diff --git a/ydb/core/viewer/browse.h b/ydb/core/viewer/browse.h
index aa29d6c0f3a4..69569a35b61c 100644
--- a/ydb/core/viewer/browse.h
+++ b/ydb/core/viewer/browse.h
@@ -1,21 +1,16 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/domain.h>
+#include "browse_events.h"
+#include "viewer.h"
+#include "wb_aggregate.h"
 #include <ydb/core/base/hive.h>
 #include <ydb/core/base/tablet.h>
 #include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
+#include <ydb/core/blobstorage/base/blobstorage_events.h>
 #include <ydb/core/tx/schemeshard/schemeshard.h>
 #include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include "browse_events.h"
-#include "viewer.h"
-#include "wb_aggregate.h"
+#include <ydb/library/actors/core/actor_bootstrapped.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -646,4 +641,3 @@ class TBrowseTabletsCommon : public TActorBootstrapped<TBrowseTabletsCommon> {
 };
 
 }
-}
diff --git a/ydb/core/viewer/browse_db.h b/ydb/core/viewer/browse_db.h
index 86c4aa264127..f794cb3bbab4 100644
--- a/ydb/core/viewer/browse_db.h
+++ b/ydb/core/viewer/browse_db.h
@@ -1,20 +1,12 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
+#include "browse.h"
+#include "viewer.h"
+#include "wb_aggregate.h"
 #include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
 #include <ydb/core/protos/table_stats.pb.h>
 #include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include "viewer.h"
-#include "browse.h"
-#include "wb_aggregate.h"
 
-namespace NKikimr {
-namespace NViewerDB {
+namespace NKikimr::NViewerDB {
 
 using namespace NViewer;
 using namespace NActors;
@@ -200,4 +192,3 @@ class TBrowseTable : public TBrowseTabletsCommon {
 };
 
 }
-}
diff --git a/ydb/core/viewer/browse_events.h b/ydb/core/viewer/browse_events.h
index ee0bbbb37572..92cc2b206bec 100644
--- a/ydb/core/viewer/browse_events.h
+++ b/ydb/core/viewer/browse_events.h
@@ -1,13 +1,12 @@
 #pragma once
 
-#include <ydb/library/actors/core/events.h>
-#include <ydb/library/actors/core/event_local.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-
 #include <util/generic/string.h>
+#include <ydb/core/base/events.h>
+#include <ydb/core/viewer/protos/viewer.pb.h>
+#include <ydb/library/actors/core/event_local.h>
+#include <ydb/library/actors/core/events.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 namespace NViewerEvents {
     enum EEv {
@@ -76,5 +75,4 @@ namespace NViewerEvents {
     };
 }   // namespace NViewerEvents
 
-}   // namespace NViewer
-}   // namespace NKikimr
+}
diff --git a/ydb/core/viewer/browse_pq.h b/ydb/core/viewer/browse_pq.h
index 1f2b5d950b16..190b72ad953b 100644
--- a/ydb/core/viewer/browse_pq.h
+++ b/ydb/core/viewer/browse_pq.h
@@ -1,20 +1,12 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/persqueue/events/global.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include "viewer.h"
 #include "browse.h"
+#include "viewer.h"
 #include "wb_aggregate.h"
+#include <ydb/core/base/tablet.h>
+#include <ydb/core/persqueue/events/global.h>
+#include <ydb/library/actors/core/actor_bootstrapped.h>
 
-namespace NKikimr {
-namespace NViewerPQ {
+namespace NKikimr::NViewerPQ {
 
 using namespace NViewer;
 using namespace NActors;
@@ -419,4 +411,3 @@ class TBrowseTopic : public TBrowseCommon {
 };
 
 }
-}
diff --git a/ydb/core/viewer/check_access.h b/ydb/core/viewer/check_access.h
deleted file mode 100644
index bf48d57f600c..000000000000
--- a/ydb/core/viewer/check_access.h
+++ /dev/null
@@ -1,226 +0,0 @@
-#pragma once
-#include <ydb/core/tx/scheme_board/cache.h>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/external_sources/external_source_factory.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/ydb_convert/ydb_convert.h>
-#include "json_pipe_req.h"
-
-namespace NKikimr {
-namespace NViewer {
-
-using namespace NActors;
-using NSchemeShard::TEvSchemeShard;
-using TNavigate = NSchemeCache::TSchemeCacheNavigate;
-
-class TCheckAccess : public TViewerPipeClient {
-    using TThis = TCheckAccess;
-    using TBase = TViewerPipeClient;
-    IViewer* Viewer;
-    NMon::TEvHttpInfo::TPtr Event;
-    TAutoPtr<TEvTxProxySchemeCache::TEvNavigateKeySetResult> CacheResult;
-    TVector<TString> Permissions;
-
-public:
-    TCheckAccess(IViewer* viewer, NMon::TEvHttpInfo::TPtr &ev)
-        : Viewer(viewer)
-        , Event(ev)
-    {}
-
-    void Bootstrap() override {
-        const auto& params(Event->Get()->Request.GetParams());
-        ui32 timeout = FromStringWithDefault<ui32>(params.Get("timeout"), 10000);
-        TString database;
-        if (params.Has("database")) {
-            database = params.Get("database");
-        } else {
-            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "field 'database' is required"));
-        }
-        if (database && database != AppData()->TenantName) {
-            BLOG_TRACE("Requesting StateStorageEndpointsLookup for " << database);
-            RequestStateStorageEndpointsLookup(database); // to find some dynamic node and redirect query there
-        } else {
-            if (params.Has("permissions")) {
-                Split(params.Get("permissions"), ",", Permissions);
-            } else {
-                return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "field 'permissions' is required"));
-            }
-            if (params.Has("path")) {
-                RequestSchemeCacheNavigate(params.Get("path"));
-            } else {
-                return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "field 'path' is required"));
-            }
-        }
-        Become(&TThis::StateRequestedNavigate, TDuration::MilliSeconds(timeout), new TEvents::TEvWakeup());
-    }
-
-    void Handle(TEvStateStorage::TEvBoardInfo::TPtr& ev) {
-        BLOG_TRACE("Received TEvBoardInfo");
-        ReplyAndPassAway(Viewer->MakeForward(Event->Get(), GetNodesFromBoardReply(ev)));
-    }
-
-    STATEFN(StateRequestedNavigate) {
-        switch (ev->GetTypeRewrite()) {
-            hFunc(TEvStateStorage::TEvBoardInfo, Handle);
-            hFunc(TEvTxProxySchemeCache::TEvNavigateKeySetResult, Handle);
-            cFunc(TEvents::TSystem::Wakeup, HandleTimeout);
-        }
-    }
-
-    void Handle(TEvTxProxySchemeCache::TEvNavigateKeySetResult::TPtr& ev) {
-        CacheResult = ev->Release();
-        RequestDone();
-    }
-
-    ui32 GetAccessType(const TString& permission) {
-        TACLAttrs attrs(0);
-        try {
-            attrs = ConvertYdbPermissionNameToACLAttrs(permission);
-        }
-        catch (const std::exception&) {
-        }
-        return attrs.AccessMask;
-    }
-
-    bool CheckAccessPermission(const NACLib::TSecurityObject* object, const NACLib::TUserToken* token, const TString& permission) {
-        const auto& kikimrRunConfig = Viewer->GetKikimrRunConfig();
-        const auto& securityConfig = kikimrRunConfig.AppConfig.GetDomainsConfig().GetSecurityConfig();
-        if (!securityConfig.GetEnforceUserTokenRequirement()) {
-            if (!securityConfig.GetEnforceUserTokenCheckRequirement() || token == nullptr) {
-                return true;
-            }
-        }
-        if (token == nullptr) {
-            return false;
-        }
-        if (object == nullptr) {
-            return false;
-        }
-        ui32 access = GetAccessType(permission);
-        if (access == 0) {
-            return false;
-        }
-        return object->CheckAccess(access, *token);
-    }
-
-    void ReplyAndPassAway() override {
-        std::unique_ptr<NACLib::TUserToken> token;
-        if (Event->Get()->UserToken) {
-            token = std::make_unique<NACLib::TUserToken>(Event->Get()->UserToken);
-        }
-        if (CacheResult == nullptr) {
-            return ReplyAndPassAway(Viewer->GetHTTPINTERNALERROR(Event->Get(), "text/plain", "no SchemeCache response"));
-        }
-        if (CacheResult->Request == nullptr) {
-            return ReplyAndPassAway(Viewer->GetHTTPINTERNALERROR(Event->Get(), "text/plain", "wrong SchemeCache response"));
-        }
-        if (CacheResult->Request.Get()->ResultSet.empty()) {
-            return ReplyAndPassAway(Viewer->GetHTTPINTERNALERROR(Event->Get(), "text/plain", "SchemeCache response is empty"));
-        }
-        if (CacheResult->Request.Get()->ErrorCount != 0) {
-            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", TStringBuilder() << "SchemeCache response error " << static_cast<int>(CacheResult->Request.Get()->ResultSet.front().Status)));
-        }
-
-
-        auto object = CacheResult->Request.Get()->ResultSet.front().SecurityObject;
-
-        NJson::TJsonValue json(NJson::JSON_MAP);
-
-        for (const TString& permission : Permissions) {
-            json[permission] = CheckAccessPermission(object.Get(), token.get(), permission);
-        }
-
-        ReplyAndPassAway(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)));
-    }
-
-    void HandleTimeout() {
-        ReplyAndPassAway(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get(), "text/plain", "Timeout receiving SchemeCache response"));
-    }
-
-    void ReplyAndPassAway(TString data) {
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(data, 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
-    }
-};
-
-template <>
-YAML::Node TJsonRequestSwagger<TCheckAccess>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        get:
-          tags:
-          - viewer
-          summary: Check access
-          description: Check access to the specified path
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            type: string
-            required: true
-          - name: path
-            in: query
-            description: path to check access
-            type: string
-            required: true
-          - name: permissions
-            in: query
-            description: permissions to check
-            required: true
-            type: array
-            items:
-              type: string
-              enum:
-               - ydb.database.connect
-               - ydb.tables.modify
-               - ydb.tables.read
-               - ydb.generic.list
-               - ydb.generic.read
-               - ydb.generic.write
-               - ydb.generic.use_legacy
-               - ydb.generic.use
-               - ydb.generic.manage
-               - ydb.generic.full_legacy
-               - ydb.generic.full
-               - ydb.database.create
-               - ydb.database.drop
-               - ydb.access.grant
-               - ydb.granular.select_row
-               - ydb.granular.update_row
-               - ydb.granular.erase_row
-               - ydb.granular.read_attributes
-               - ydb.granular.write_attributes
-               - ydb.granular.create_directory
-               - ydb.granular.create_table
-               - ydb.granular.create_queue
-               - ydb.granular.remove_schema
-               - ydb.granular.describe_schema
-               - ydb.granular.alter_schema
-          - name: timeout
-            in: query
-            description: timeout in ms
-            required: false
-            type: integer
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-
-    return node;
-}
-
-}
-}
-
diff --git a/ydb/core/viewer/counters_hosts.h b/ydb/core/viewer/counters_hosts.h
index 2232f16b00ba..b93a7cb0b485 100644
--- a/ydb/core/viewer/counters_hosts.h
+++ b/ydb/core/viewer/counters_hosts.h
@@ -1,16 +1,12 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/actors/interconnect/interconnect.h>
+#include "viewer.h"
 #include <library/cpp/json/json_writer.h>
 #include <ydb/core/base/nameservice.h>
-#include <ydb/library/services/services.pb.h>
 #include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include "viewer.h"
+#include <ydb/library/actors/core/actor_bootstrapped.h>
+#include <ydb/library/actors/interconnect/interconnect.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
@@ -173,4 +169,3 @@ class TCountersHostsList : public TActorBootstrapped<TCountersHostsList> {
 };
 
 }
-}
diff --git a/ydb/core/viewer/healthcheck_record.h b/ydb/core/viewer/healthcheck_record.h
index 39c94e288773..5b55d2bd1322 100644
--- a/ydb/core/viewer/healthcheck_record.h
+++ b/ydb/core/viewer/healthcheck_record.h
@@ -1,9 +1,8 @@
 #pragma once
+#include <util/digest/numeric.h>
+#include <util/generic/string.h>
 
 namespace NKikimr::NViewer {
-    
-using namespace NActors;
-using namespace NMonitoring;
 
 struct TMetricRecord {
     TString Database;
diff --git a/ydb/core/viewer/json_blobindexstat.h b/ydb/core/viewer/json_blobindexstat.h
deleted file mode 100644
index 2cdf56b4bc4f..000000000000
--- a/ydb/core/viewer/json_blobindexstat.h
+++ /dev/null
@@ -1,30 +0,0 @@
-#pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/util/tuples.h>
-#include "json_vdisk_req.h"
-
-namespace NKikimr {
-namespace NViewer {
-
-using TJsonBlobIndexStat = TJsonVDiskRequest<TEvGetLogoBlobIndexStatRequest, TEvGetLogoBlobIndexStatResponse>;
-
-template <>
-struct TJsonRequestSummary<TJsonBlobIndexStat> {
-    static TString GetSummary() {
-        return "\"Get logoblob index stat from VDisk\"";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonBlobIndexStat> {
-    static TString GetDescription() {
-        return "\"Get logoblob index stat from VDisk\"";
-    }
-};
-
-}
-}
diff --git a/ydb/core/viewer/json_bscontrollerinfo.h b/ydb/core/viewer/json_bscontrollerinfo.h
deleted file mode 100644
index cf1833742f57..000000000000
--- a/ydb/core/viewer/json_bscontrollerinfo.h
+++ /dev/null
@@ -1,122 +0,0 @@
-#pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include "viewer.h"
-#include "json_pipe_req.h"
-#include <ydb/core/viewer/json/json.h>
-
-namespace NKikimr {
-namespace NViewer {
-
-using namespace NActors;
-
-class TJsonBSControllerInfo : public TViewerPipeClient {
-    using TThis = TJsonBSControllerInfo;
-    using TBase = TViewerPipeClient;
-    IViewer* Viewer;
-    NMon::TEvHttpInfo::TPtr Event;
-    TAutoPtr<TEvBlobStorage::TEvResponseControllerInfo> ControllerInfo;
-    TJsonSettings JsonSettings;
-    ui32 Timeout = 0;
-
-public:
-    TJsonBSControllerInfo(IViewer* viewer, NMon::TEvHttpInfo::TPtr &ev)
-        : Viewer(viewer)
-        , Event(ev)
-    {}
-
-    void Bootstrap() override {
-        const auto& params(Event->Get()->Request.GetParams());
-        JsonSettings.EnumAsNumbers = !FromStringWithDefault<bool>(params.Get("enums"), false);
-        JsonSettings.UI64AsString = !FromStringWithDefault<bool>(params.Get("ui64"), false);
-        Timeout = FromStringWithDefault<ui32>(params.Get("timeout"), 10000);
-        InitConfig(params);
-        RequestBSControllerInfo();
-        const auto ctx = TActivationContext::ActorContextFor(SelfId());
-        Become(&TThis::StateRequestedInfo, ctx, TDuration::MilliSeconds(Timeout), new TEvents::TEvWakeup());
-    }
-
-    STATEFN(StateRequestedInfo) {
-        switch (ev->GetTypeRewrite()) {
-            hFunc(TEvBlobStorage::TEvResponseControllerInfo, Handle);
-            hFunc(TEvTabletPipe::TEvClientConnected, TBase::Handle);
-            cFunc(TEvents::TSystem::Wakeup, HandleTimeout);
-        }
-    }
-
-    void Handle(TEvBlobStorage::TEvResponseControllerInfo::TPtr& ev) {
-        ControllerInfo = ev->Release();
-        RequestDone();
-    }
-
-    void ReplyAndPassAway() override {
-        TStringStream json;
-        if (ControllerInfo != nullptr) {
-            TProtoToJson::ProtoToJson(json, ControllerInfo->Record);
-        } else {
-            json << "null";
-        }
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), json.Str()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
-    }
-
-    void HandleTimeout() {
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
-    }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonBSControllerInfo> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<TEvBlobStorage::TEvResponseControllerInfo::ProtoRecordType>();
-    }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonBSControllerInfo> {
-    static YAML::Node GetParameters() {
-        return YAML::Node(R"___(
-            - name: controller_id
-              in: query
-              description: storage controller identifier (tablet id)
-              required: true
-              type: string
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-        )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonBSControllerInfo> {
-    static TString GetSummary() {
-        return "Storage controller information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonBSControllerInfo> {
-    static TString GetDescription() {
-        return "Returns information about storage controller";
-    }
-};
-
-}
-}
diff --git a/ydb/core/viewer/json_describe_consumer.h b/ydb/core/viewer/json_describe_consumer.h
deleted file mode 100644
index 693f5cc5e065..000000000000
--- a/ydb/core/viewer/json_describe_consumer.h
+++ /dev/null
@@ -1,107 +0,0 @@
-#pragma once
-#include <ydb/public/api/grpc/ydb_topic_v1.grpc.pb.h>
-#include <ydb/core/grpc_services/rpc_calls_topic.h>
-#include "json_local_rpc.h"
-
-namespace NKikimr {
-namespace NViewer {
-
-using TDescribeConsumerRpc = TJsonLocalRpc<Ydb::Topic::DescribeConsumerRequest,
-                                         Ydb::Topic::DescribeConsumerResponse,
-                                         Ydb::Topic::DescribeConsumerResult,
-                                         Ydb::Topic::V1::TopicService,
-                                         NKikimr::NGRpcService::TEvDescribeConsumerRequest>;
-
-class TJsonDescribeConsumer : public TDescribeConsumerRpc {
-public:
-    using TBase = TDescribeConsumerRpc;
-
-    TJsonDescribeConsumer(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
-        : TBase(viewer, ev)
-    {}
-
-    void Bootstrap() override {
-        if (Event->Get()->Request.GetMethod() != HTTP_METHOD_GET) {
-            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "Only GET method is allowed"));
-        }
-        const auto& params(Event->Get()->Request.GetParams());
-        if (params.Has("database")) {
-            Database = params.Get("database");
-        } else if (params.Has("database_path")) {
-            Database = params.Get("database_path");
-        } else {
-            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "field 'database' is required"));
-        }
-
-        if (params.Has("consumer")) {
-            Request.set_consumer(params.Get("consumer"));
-        } else {
-            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "field 'consumer' is required"));
-        }
-
-        if (params.Has("include_stats")) {
-            Request.set_include_stats(FromStringWithDefault<bool>(params.Get("include_stats"), false));
-        }
-
-        TBase::Bootstrap();
-    }
-};
-
-template<>
-YAML::Node TJsonRequestSwagger<TJsonDescribeConsumer>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        get:
-          tags:
-          - viewer
-          summary: Topic schema detailed information
-          description: Returns detailed information about topic
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: consumer
-            in: query
-            description: consumer name
-            required: true
-            type: string
-          - name: include_stats
-            in: query
-            description: include stat flag
-            required: false
-            type: bool
-          - name: timeout
-            in: query
-            description: timeout in ms
-            required: false
-            type: integer
-          - name: enums
-            in: query
-            description: convert enums to strings
-            required: false
-            type: boolean
-          - name: ui64
-            in: query
-            description: return ui64 as number
-            required: false
-            type: boolean
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-    node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Topic::DescribeConsumerResult>();
-    return node;
-}
-
-}
-}
diff --git a/ydb/core/viewer/json_handlers.cpp b/ydb/core/viewer/json_handlers.cpp
new file mode 100644
index 000000000000..7f7b070dd37b
--- /dev/null
+++ b/ydb/core/viewer/json_handlers.cpp
@@ -0,0 +1,47 @@
+#include "json_handlers.h"
+#include <library/cpp/yaml/as/tstring.h>
+
+namespace NKikimr::NViewer {
+
+TSimpleYamlBuilder::TSimpleYamlBuilder(TInitializer initializer) {
+    Method = Root[TString(initializer.Method)];
+    if (initializer.Url) {
+        Method["tags"].push_back(TString(initializer.Url.After('/').Before('/')));
+    }
+    if (initializer.Tag) {
+        Method["tags"].push_back(TString(initializer.Tag));
+    }
+    if (initializer.Summary) {
+        Method["summary"] = TString(initializer.Summary);
+    }
+    if (initializer.Description) {
+        Method["description"] = TString(initializer.Description);
+    }
+}
+
+void TSimpleYamlBuilder::SetParameters(YAML::Node parameters) {
+    Method["parameters"] = parameters;
+}
+
+void TSimpleYamlBuilder::AddParameter(TParameter parameter) {
+    YAML::Node param;
+    param["in"] = "query";
+    param["name"] = TString(parameter.Name);
+    if (parameter.Description) {
+        param["description"] = TString(parameter.Description);
+    }
+    if (parameter.Type) {
+        param["type"] = TString(parameter.Type);
+    }
+    if (parameter.Default) {
+        param["default"] = TString(parameter.Default);
+    }
+    param["required"] = parameter.Required;
+    Method["parameters"].push_back(param);
+}
+
+void TSimpleYamlBuilder::SetResponseSchema(YAML::Node schema) {
+    Method["responses"]["200"]["content"]["application/json"]["schema"] = schema;
+}
+
+}
diff --git a/ydb/core/viewer/json_handlers.h b/ydb/core/viewer/json_handlers.h
index 0a994546740d..81dfe70eb016 100644
--- a/ydb/core/viewer/json_handlers.h
+++ b/ydb/core/viewer/json_handlers.h
@@ -1,7 +1,7 @@
 #pragma once
-
 #include "viewer.h"
-#include <library/cpp/yaml/as/tstring.h>
+#include <ydb/core/viewer/json/json.h>
+#include <ydb/core/viewer/yaml/yaml.h>
 
 namespace NKikimr::NViewer {
 
@@ -9,43 +9,24 @@ class TJsonHandlerBase {
 public:
     virtual ~TJsonHandlerBase() = default;
     virtual IActor* CreateRequestActor(IViewer* viewer, NMon::TEvHttpInfo::TPtr& event) = 0;
-    virtual YAML::Node GetResponseJsonSchema() = 0;
-    virtual TString GetRequestSummary() = 0;
-    virtual TString GetRequestDescription() = 0;
-    virtual YAML::Node GetRequestParameters() = 0;
     virtual YAML::Node GetRequestSwagger() = 0;
 };
 
 template <typename ActorRequestType>
 class TJsonHandler : public TJsonHandlerBase {
 public:
-    IActor* CreateRequestActor(IViewer* viewer, NMon::TEvHttpInfo::TPtr& event) override {
-        return new ActorRequestType(viewer, event);
-    }
-
-    YAML::Node GetResponseJsonSchema() override {
-        static YAML::Node jsonSchema = TJsonRequestSchema<ActorRequestType>::GetSchema();
-        return jsonSchema;
-    }
+    YAML::Node Swagger;
 
-    TString GetRequestSummary() override {
-        static TString summary = TJsonRequestSummary<ActorRequestType>::GetSummary();
-        return summary;
-    }
+    TJsonHandler(YAML::Node swagger)
+        : Swagger(swagger)
+    {}
 
-    TString GetRequestDescription() override {
-        static TString description = TJsonRequestDescription<ActorRequestType>::GetDescription();
-        return description;
-    }
-
-    YAML::Node GetRequestParameters() override {
-        static YAML::Node parameters = TJsonRequestParameters<ActorRequestType>::GetParameters();
-        return parameters;
+    IActor* CreateRequestActor(IViewer* viewer, NMon::TEvHttpInfo::TPtr& event) override {
+        return new ActorRequestType(viewer, event);
     }
 
     YAML::Node GetRequestSwagger() override {
-        static YAML::Node swagger = TJsonRequestSwagger<ActorRequestType>::GetSwagger();
-        return swagger;
+        return Swagger;
     }
 };
 
@@ -69,4 +50,35 @@ struct TJsonHandlers {
     }
 };
 
+class TSimpleYamlBuilder {
+public:
+    struct TInitializer {
+        TStringBuf Method;
+        TStringBuf Tag;
+        TStringBuf Url;
+        TStringBuf Summary;
+        TStringBuf Description;
+    };
+
+    struct TParameter {
+        TStringBuf Name;
+        TStringBuf Description;
+        TStringBuf Type;
+        TStringBuf Default;
+        bool Required = false;
+    };
+
+    YAML::Node Root;
+    YAML::Node Method;
+
+    TSimpleYamlBuilder(TInitializer initializer);
+    void SetParameters(YAML::Node parameters);
+    void AddParameter(TParameter parameter);
+    void SetResponseSchema(YAML::Node schema);
+
+    operator YAML::Node() {
+        return Root;
+    }
+};
+
 } // namespace NKikimr::NViewer
diff --git a/ydb/core/viewer/json_handlers_browse.cpp b/ydb/core/viewer/json_handlers_browse.cpp
new file mode 100644
index 000000000000..c9ec41656d8f
--- /dev/null
+++ b/ydb/core/viewer/json_handlers_browse.cpp
@@ -0,0 +1,37 @@
+#include "json_handlers.h"
+#include "browse.h"
+#include "browse_db.h"
+#include "browse_pq.h"
+#include "viewer_browse.h"
+#include "viewer_content.h"
+#include "viewer_metainfo.h"
+
+namespace NKikimr::NViewer {
+
+void SetupDBVirtualHandlers(IViewer* viewer) {
+    viewer->RegisterVirtualHandler(
+        NKikimrViewer::EObjectType::Table,
+        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
+            return new NViewerDB::TBrowseTable(owner, browseContext);
+        });
+}
+
+void InitViewerMetaInfoJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/metainfo", new TJsonHandler<TJsonMetaInfo>(TJsonMetaInfo::GetSwagger()));
+}
+
+void InitViewerBrowseJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/browse", new TJsonHandler<TJsonBrowse>(TJsonBrowse::GetSwagger()));
+}
+
+void InitViewerContentJsonHandler(TJsonHandlers &jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/content", new TJsonHandler<TJsonContent>(TJsonContent::GetSwagger()));
+}
+
+void InitViewerBrowseJsonHandlers(TJsonHandlers& jsonHandlers) {
+    InitViewerMetaInfoJsonHandler(jsonHandlers);
+    InitViewerBrowseJsonHandler(jsonHandlers);
+    InitViewerContentJsonHandler(jsonHandlers);
+}
+
+}
diff --git a/ydb/core/viewer/json_handlers_operation.cpp b/ydb/core/viewer/json_handlers_operation.cpp
index 4e9c90da6d79..7375d177983b 100644
--- a/ydb/core/viewer/json_handlers_operation.cpp
+++ b/ydb/core/viewer/json_handlers_operation.cpp
@@ -1,17 +1,32 @@
 #include "json_handlers.h"
-
-#include "operation_get.h"
-#include "operation_list.h"
 #include "operation_cancel.h"
 #include "operation_forget.h"
+#include "operation_get.h"
+#include "operation_list.h"
 
 namespace NKikimr::NViewer {
 
-void InitOperationJsonHandlers(TJsonHandlers& jsonHandlers) {
-    jsonHandlers.AddHandler("/operation/get", new TJsonHandler<TOperationGet>);
-    jsonHandlers.AddHandler("/operation/list", new TJsonHandler<TOperationList>);
-    jsonHandlers.AddHandler("/operation/cancel", new TJsonHandler<TOperationCancel>);
-    jsonHandlers.AddHandler("/operation/forget", new TJsonHandler<TOperationForget>);
+void InitOperationGetJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/operation/get", new TJsonHandler<TOperationGet>(TOperationGet::GetSwagger()));
+}
+
+void InitOperationListJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/operation/list", new TJsonHandler<TOperationList>(TOperationList::GetSwagger()));
+}
+
+void InitOperationCancelJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/operation/cancel", new TJsonHandler<TOperationCancel>(TOperationCancel::GetSwagger()));
 }
 
+void InitOperationForgetJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/operation/forget", new TJsonHandler<TOperationForget>(TOperationForget::GetSwagger()));
 }
+
+void InitOperationJsonHandlers(TJsonHandlers& jsonHandlers) {
+    InitOperationGetJsonHandler(jsonHandlers);
+    InitOperationListJsonHandler(jsonHandlers);
+    InitOperationCancelJsonHandler(jsonHandlers);
+    InitOperationForgetJsonHandler(jsonHandlers);
+}
+
+} // namespace NKikimr::NViewer
diff --git a/ydb/core/viewer/json_handlers_pdisk.cpp b/ydb/core/viewer/json_handlers_pdisk.cpp
index ef99307e25be..55845fc83cad 100644
--- a/ydb/core/viewer/json_handlers_pdisk.cpp
+++ b/ydb/core/viewer/json_handlers_pdisk.cpp
@@ -1,19 +1,26 @@
-#include <ydb/core/blobstorage/vdisk/common/vdisk_events.h>
-#include <ydb/core/blobstorage/base/blobstorage_events.h>
-
 #include "json_handlers.h"
-
-#include "json_pdisk_restart.h"
 #include "pdisk_info.h"
+#include "pdisk_restart.h"
 #include "pdisk_status.h"
 
-
 namespace NKikimr::NViewer {
 
+void InitPDiskInfoJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/pdisk/info", new TJsonHandler<TPDiskInfo>(TPDiskInfo::GetSwagger()));
+}
+
+void InitPDiskRestartJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/pdisk/restart", new TJsonHandler<TJsonPDiskRestart>(TJsonPDiskRestart::GetSwagger()));
+}
+
+void InitPDiskStatusJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/pdisk/status", new TJsonHandler<TPDiskStatus>(TPDiskStatus::GetSwagger()));
+}
+
 void InitPDiskJsonHandlers(TJsonHandlers& jsonHandlers) {
-    jsonHandlers.AddHandler("/pdisk/info", new TJsonHandler<TPDiskInfo>);
-    jsonHandlers.AddHandler("/pdisk/restart", new TJsonHandler<TJsonPDiskRestart>);
-    jsonHandlers.AddHandler("/pdisk/status", new TJsonHandler<TPDiskStatus>);
+    InitPDiskInfoJsonHandler(jsonHandlers);
+    InitPDiskRestartJsonHandler(jsonHandlers);
+    InitPDiskStatusJsonHandler(jsonHandlers);
 }
 
 }
diff --git a/ydb/core/viewer/json_handlers_pq.cpp b/ydb/core/viewer/json_handlers_pq.cpp
new file mode 100644
index 000000000000..d3503b95b7f9
--- /dev/null
+++ b/ydb/core/viewer/json_handlers_pq.cpp
@@ -0,0 +1,29 @@
+#include "viewer.h"
+#include "browse_pq.h"
+
+namespace NKikimr::NViewer {
+
+void SetupPQVirtualHandlers(IViewer* viewer) {
+    viewer->RegisterVirtualHandler(
+        NKikimrViewer::EObjectType::Root,
+        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
+            return new NViewerPQ::TBrowseRoot(owner, browseContext);
+        });
+    viewer->RegisterVirtualHandler(
+        NKikimrViewer::EObjectType::Consumers,
+        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
+            return new NViewerPQ::TBrowseConsumers(owner, browseContext);
+        });
+    viewer->RegisterVirtualHandler(
+        NKikimrViewer::EObjectType::Consumer,
+        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
+            return new NViewerPQ::TBrowseConsumer(owner, browseContext);
+        });
+    viewer->RegisterVirtualHandler(
+        NKikimrViewer::EObjectType::Topic,
+        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
+            return new NViewerPQ::TBrowseTopic(owner, browseContext);
+        });
+}
+
+}
diff --git a/ydb/core/viewer/json_handlers_scheme.cpp b/ydb/core/viewer/json_handlers_scheme.cpp
index c5dc07f28b28..2f1529393c6d 100644
--- a/ydb/core/viewer/json_handlers_scheme.cpp
+++ b/ydb/core/viewer/json_handlers_scheme.cpp
@@ -1,11 +1,14 @@
 #include "json_handlers.h"
-
 #include "scheme_directory.h"
 
 namespace NKikimr::NViewer {
 
+void InitSchemeDirectoryHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/scheme/directory", new TJsonSchemeDirectoryHandler());
+}
+
 void InitSchemeJsonHandlers(TJsonHandlers& jsonHandlers) {
-    jsonHandlers.AddHandler("/scheme/directory", new TJsonSchemeDirectoryHandler());
+    InitSchemeDirectoryHandler(jsonHandlers);
 }
 
 }
diff --git a/ydb/core/viewer/json_handlers_storage.cpp b/ydb/core/viewer/json_handlers_storage.cpp
index 352f8c3d7c4a..bcd470f1de86 100644
--- a/ydb/core/viewer/json_handlers_storage.cpp
+++ b/ydb/core/viewer/json_handlers_storage.cpp
@@ -1,9 +1,11 @@
-
 #include "json_handlers.h"
+#include "storage_groups.h"
 
 namespace NKikimr::NViewer {
 
-void InitStorageGroupsJsonHandler(TJsonHandlers& jsonHandlers);
+void InitStorageGroupsJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/storage/groups", new TJsonHandler<TStorageGroups>(TStorageGroups::GetSwagger()));
+}
 
 void InitStorageJsonHandlers(TJsonHandlers& jsonHandlers) {
     InitStorageGroupsJsonHandler(jsonHandlers);
diff --git a/ydb/core/viewer/json_handlers_vdisk.cpp b/ydb/core/viewer/json_handlers_vdisk.cpp
index 49c869692f08..633bf9c80566 100644
--- a/ydb/core/viewer/json_handlers_vdisk.cpp
+++ b/ydb/core/viewer/json_handlers_vdisk.cpp
@@ -1,20 +1,56 @@
-#include <ydb/core/blobstorage/vdisk/common/vdisk_events.h>
-#include <ydb/core/blobstorage/base/blobstorage_events.h>
-
 #include "json_handlers.h"
-
-#include "json_vdiskstat.h"
-#include "json_getblob.h"
-#include "json_blobindexstat.h"
-#include "json_vdisk_evict.h"
+#include "vdisk_vdiskstat.h"
+#include "vdisk_blobindexstat.h"
+#include "vdisk_getblob.h"
+#include "vdisk_evict.h"
 
 namespace NKikimr::NViewer {
 
+void InitVDiskStatJsonHandler(TJsonHandlers& handlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "vdisk",
+        .Summary = "VDisk statistic",
+        .Description = "VDisk statistic",
+    });
+    yaml.SetParameters(TJsonVDiskStat::GetParameters());
+    yaml.SetResponseSchema(TJsonVDiskStat::GetSchema());
+    handlers.AddHandler("/vdisk/vdiskstat", new TJsonHandler<TJsonVDiskStat>(yaml));
+}
+
+void InitVDiskGetBlobJsonHandler(TJsonHandlers& handlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "vdisk",
+        .Summary = "Get blob from VDisk",
+        .Description = "Get blob from VDisk",
+    });
+    yaml.SetParameters(TJsonGetBlob::GetParameters());
+    yaml.SetResponseSchema(TJsonGetBlob::GetSchema());
+    handlers.AddHandler("/vdisk/getblob", new TJsonHandler<TJsonGetBlob>(yaml));
+}
+
+void InitVDiskBlobIndexStatJsonHandler(TJsonHandlers& jsonHandlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "vdisk",
+        .Summary = "Get logoblob index stat from VDisk",
+        .Description = "Get logoblob index stat from VDisk",
+    });
+    yaml.SetParameters(TJsonBlobIndexStat::GetParameters());
+    yaml.SetResponseSchema(TJsonBlobIndexStat::GetSchema());
+    jsonHandlers.AddHandler("/vdisk/blobindexstat", new TJsonHandler<TJsonBlobIndexStat>(yaml));
+}
+
+void InitVDiskEvictJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/vdisk/evict", new TJsonHandler<TJsonVDiskEvict>(TJsonVDiskEvict::GetSwagger()));
+}
+
 void InitVDiskJsonHandlers(TJsonHandlers& jsonHandlers) {
-    jsonHandlers.AddHandler("/vdisk/vdiskstat", new TJsonHandler<TJsonVDiskStat>);
-    jsonHandlers.AddHandler("/vdisk/getblob", new TJsonHandler<TJsonGetBlob>);
-    jsonHandlers.AddHandler("/vdisk/blobindexstat", new TJsonHandler<TJsonBlobIndexStat>);
-    jsonHandlers.AddHandler("/vdisk/evict", new TJsonHandler<TJsonVDiskEvict>);
+    InitVDiskStatJsonHandler(jsonHandlers);
+    InitVDiskGetBlobJsonHandler(jsonHandlers);
+    InitVDiskBlobIndexStatJsonHandler(jsonHandlers);
+    InitVDiskEvictJsonHandler(jsonHandlers);
 }
 
 }
diff --git a/ydb/core/viewer/json_handlers_viewer.cpp b/ydb/core/viewer/json_handlers_viewer.cpp
index e037c4f4ea84..fcbf52aa0965 100644
--- a/ydb/core/viewer/json_handlers_viewer.cpp
+++ b/ydb/core/viewer/json_handlers_viewer.cpp
@@ -1,92 +1,308 @@
-#include <ydb/core/blobstorage/base/blobstorage_events.h>
-
 #include "json_handlers.h"
-
-#include "json_nodelist.h"
-#include "json_nodeinfo.h"
-#include "json_vdiskinfo.h"
-#include "json_pdiskinfo.h"
-#include "json_describe.h"
-#include "json_describe_topic.h"
-#include "json_describe_consumer.h"
-#include "json_hotkeys.h"
-#include "json_sysinfo.h"
-#include "json_tabletinfo.h"
-#include "json_hiveinfo.h"
-#include "json_bsgroupinfo.h"
-#include "json_bscontrollerinfo.h"
-#include "json_config.h"
-#include "json_counters.h"
-#include "json_topicinfo.h"
-#include "json_pqconsumerinfo.h"
-#include "json_tabletcounters.h"
-#include "json_storage.h"
-#include "json_storage_usage.h"
-#include "json_metainfo.h"
-#include "json_browse.h"
-#include "json_cluster.h"
-#include "json_content.h"
-#include "json_labeledcounters.h"
-#include "json_tenants.h"
-#include "json_hivestats.h"
-#include "json_tenantinfo.h"
-#include "json_whoami.h"
-#include "json_query.h"
-#include "json_netinfo.h"
-#include "json_compute.h"
-#include "json_healthcheck.h"
-#include "json_nodes.h"
-#include "json_acl.h"
-#include "json_graph.h"
-#include "json_render.h"
-#include "json_autocomplete.h"
-#include "check_access.h"
+#include "viewer_acl.h"
+#include "viewer_autocomplete.h"
+#include "viewer_bscontrollerinfo.h"
+#include "viewer_capabilities.h"
+#include "viewer_check_access.h"
+#include "viewer_cluster.h"
+#include "viewer_compute.h"
+#include "viewer_config.h"
+#include "viewer_counters.h"
+#include "viewer_describe_consumer.h"
+#include "viewer_describe.h"
+#include "viewer_describe_topic.h"
+#include "viewer_graph.h"
+#include "viewer_healthcheck.h"
+#include "viewer_hiveinfo.h"
+#include "viewer_hivestats.h"
+#include "viewer_hotkeys.h"
+#include "viewer_labeled_counters.h"
+#include "viewer_netinfo.h"
+#include "viewer_nodelist.h"
+#include "viewer_nodes.h"
+#include "viewer_pqconsumerinfo.h"
+#include "viewer_query.h"
+#include "viewer_render.h"
+#include "viewer_storage.h"
+#include "viewer_storage_usage.h"
+#include "viewer_tabletcounters.h"
+#include "viewer_tenantinfo.h"
+#include "viewer_tenants.h"
+#include "viewer_topicinfo.h"
+#include "viewer_whoami.h"
 
 namespace NKikimr::NViewer {
 
-void InitViewerCapabilitiesJsonHandler(TJsonHandlers& jsonHandlers);
+TBSGroupState GetBSGroupOverallStateWithoutLatency(
+        const NKikimrWhiteboard::TBSGroupStateInfo& info,
+        const TMap<NKikimrBlobStorage::TVDiskID, const NKikimrWhiteboard::TVDiskStateInfo&>& vDisksIndex,
+        const TMap<std::pair<ui32, ui32>, const NKikimrWhiteboard::TPDiskStateInfo&>& pDisksIndex) {
+
+    TBSGroupState groupState;
+    groupState.Overall = NKikimrViewer::EFlag::Grey;
+
+    const auto& vDiskIds = info.GetVDiskIds();
+    std::unordered_map<ui32, ui32> failedRings;
+    std::unordered_map<ui32, ui32> failedDomains;
+    TVector<NKikimrViewer::EFlag> vDiskFlags;
+    vDiskFlags.reserve(vDiskIds.size());
+    for (auto iv = vDiskIds.begin(); iv != vDiskIds.end(); ++iv) {
+        const NKikimrBlobStorage::TVDiskID& vDiskId = *iv;
+        NKikimrViewer::EFlag flag = NKikimrViewer::EFlag::Grey;
+        auto ie = vDisksIndex.find(vDiskId);
+        if (ie != vDisksIndex.end()) {
+            auto pDiskId = std::make_pair(ie->second.GetNodeId(), ie->second.GetPDiskId());
+            auto ip = pDisksIndex.find(pDiskId);
+            if (ip != pDisksIndex.end()) {
+                const NKikimrWhiteboard::TPDiskStateInfo& pDiskInfo(ip->second);
+                flag = Max(flag, GetPDiskOverallFlag(pDiskInfo));
+            } else {
+                flag = NKikimrViewer::EFlag::Red;
+            }
+            const NKikimrWhiteboard::TVDiskStateInfo& vDiskInfo(ie->second);
+            flag = Max(flag, GetVDiskOverallFlag(vDiskInfo));
+            if (vDiskInfo.GetDiskSpace() > NKikimrWhiteboard::EFlag::Green) {
+                groupState.SpaceProblems++;
+            }
+        } else {
+            flag = NKikimrViewer::EFlag::Red;
+        }
+        vDiskFlags.push_back(flag);
+        if (flag == NKikimrViewer::EFlag::Red || flag == NKikimrViewer::EFlag::Blue) {
+            groupState.MissingDisks++;
+            ++failedRings[vDiskId.GetRing()];
+            ++failedDomains[vDiskId.GetDomain()];
+        }
+        groupState.Overall = Max(groupState.Overall, flag);
+    }
+
+    groupState.Overall = Min(groupState.Overall, NKikimrViewer::EFlag::Yellow); // without failed rings we only allow to raise group status up to Blue/Yellow
+    TString erasure = info.GetErasureSpecies();
+    if (erasure == TErasureType::ErasureSpeciesName(TErasureType::ErasureNone)) {
+        if (!failedDomains.empty()) {
+            groupState.Overall = NKikimrViewer::EFlag::Red;
+        }
+    } else if (erasure == TErasureType::ErasureSpeciesName(TErasureType::ErasureMirror3dc)) {
+        if (failedRings.size() > 2) {
+            groupState.Overall = NKikimrViewer::EFlag::Red;
+        } else if (failedRings.size() == 2) { // TODO: check for 1 ring - 1 domain rule
+            groupState.Overall = NKikimrViewer::EFlag::Orange;
+        } else if (failedRings.size() > 0) {
+            groupState.Overall = Min(groupState.Overall, NKikimrViewer::EFlag::Yellow);
+        }
+    } else if (erasure == TErasureType::ErasureSpeciesName(TErasureType::Erasure4Plus2Block)) {
+        if (failedDomains.size() > 2) {
+            groupState.Overall = NKikimrViewer::EFlag::Red;
+        } else if (failedDomains.size() > 1) {
+            groupState.Overall = NKikimrViewer::EFlag::Orange;
+        } else if (failedDomains.size() > 0) {
+            groupState.Overall = Min(groupState.Overall, NKikimrViewer::EFlag::Yellow);
+        }
+    }
+    return groupState;
+}
+
+NKikimrViewer::EFlag GetBSGroupOverallFlagWithoutLatency(
+        const NKikimrWhiteboard::TBSGroupStateInfo& info,
+        const TMap<NKikimrBlobStorage::TVDiskID, const NKikimrWhiteboard::TVDiskStateInfo&>& vDisksIndex,
+        const TMap<std::pair<ui32, ui32>, const NKikimrWhiteboard::TPDiskStateInfo&>& pDisksIndex) {
+    return GetBSGroupOverallStateWithoutLatency(info, vDisksIndex, pDisksIndex).Overall;
+}
+
+TBSGroupState GetBSGroupOverallState(
+        const NKikimrWhiteboard::TBSGroupStateInfo& info,
+        const TMap<NKikimrBlobStorage::TVDiskID, const NKikimrWhiteboard::TVDiskStateInfo&>& vDisksIndex,
+        const TMap<std::pair<ui32, ui32>, const NKikimrWhiteboard::TPDiskStateInfo&>& pDisksIndex) {
+    TBSGroupState state = GetBSGroupOverallStateWithoutLatency(info, vDisksIndex, pDisksIndex);
+    if (info.HasLatency()) {
+        state.Overall = Max(state.Overall, Min(NKikimrViewer::EFlag::Yellow, GetViewerFlag(info.GetLatency())));
+    }
+    return state;
+}
+
+NKikimrViewer::EFlag GetBSGroupOverallFlag(
+        const NKikimrWhiteboard::TBSGroupStateInfo& info,
+        const TMap<NKikimrBlobStorage::TVDiskID, const NKikimrWhiteboard::TVDiskStateInfo&>& vDisksIndex,
+        const TMap<std::pair<ui32, ui32>, const NKikimrWhiteboard::TPDiskStateInfo&>& pDisksIndex) {
+    return GetBSGroupOverallState(info, vDisksIndex, pDisksIndex).Overall;
+}
+
+void InitViewerCapabilitiesJsonHandler(TJsonHandlers& jsonHandlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "viewer",
+        .Summary = "Viewer capabilities",
+        .Description = "Viewer capabilities",
+    });
+    jsonHandlers.AddHandler("/viewer/capabilities", new TJsonHandler<TViewerCapabilities>(yaml));
+}
+
+void InitViewerNodelistJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/nodelist", new TJsonHandler<TJsonNodeList>(TJsonNodeList::GetSwagger()));
+}
+
+void InitViewerNodeInfoJsonHandler(TJsonHandlers& jsonHandlers);
+void InitViewerSysInfoJsonHandler(TJsonHandlers& jsonHandlers);
+void InitViewerVDiskInfoJsonHandler(TJsonHandlers& jsonHandlers);
+void InitViewerPDiskInfoJsonHandler(TJsonHandlers& jsonHandlers);
+void InitViewerTabletInfoJsonHandler(TJsonHandlers& jsonHandlers);
+
+void InitViewerDescribeJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/describe", new TJsonHandler<TJsonDescribe>(TJsonDescribe::GetSwagger()));
+}
+
+void InitViewerDescribeTopicJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/describe_topic", new TJsonHandler<TJsonDescribeTopic>(TJsonDescribeTopic::GetSwagger()));
+}
+
+void InitViewerDescribeConsumerJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/describe_consumer", new TJsonHandler<TJsonDescribeConsumer>(TJsonDescribeConsumer::GetSwagger()));
+}
+
+void InitViewerHotkeysJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/hotkeys", new TJsonHandler<TJsonHotkeys>(TJsonHotkeys::GetSwagger()));
+}
+
+void InitViewerHiveInfoJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/hiveinfo", new TJsonHandler<TJsonHiveInfo>(TJsonHiveInfo::GetSwagger()));
+}
+
+void InitViewerBSGroupInfoJsonHandler(TJsonHandlers& jsonHandlers);
+
+void InitViewerBSControllerInfoJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/bscontrollerinfo", new TJsonHandler<TJsonBSControllerInfo>(TJsonBSControllerInfo::GetSwagger()));
+}
+
+void InitViewerConfigJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/config", new TJsonHandler<TJsonConfig>(TJsonConfig::GetSwagger()));
+}
+
+void InitViewerCountersJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/counters", new TJsonHandler<TJsonCounters>(TJsonCounters::GetSwagger()));
+}
+
+void InitViewerTopicInfoJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/topicinfo", new TJsonHandler<TJsonTopicInfo>(TJsonTopicInfo::GetSwagger()));
+}
+
+void InitViewerPQConsumerInfoJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/pqconsumerinfo", new TJsonHandler<TJsonPQConsumerInfo>(TJsonPQConsumerInfo::GetSwagger()));
+}
+
+void InitViewerTabletCountersJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/tabletcounters", new TJsonHandler<TJsonTabletCounters>(TJsonTabletCounters::GetSwagger()));
+}
+
+void InitViewerStorageJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/storage", new TJsonHandler<TJsonStorage>(TJsonStorage::GetSwagger()));
+}
+
+void InitViewerStorageUsageJsonHandler(TJsonHandlers &handlers) {
+    handlers.AddHandler("/viewer/storage_usage", new TJsonHandler<TJsonStorageUsage>(TJsonStorageUsage::GetSwagger()));
+}
+
+void InitViewerClusterJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/cluster", new TJsonHandler<TJsonCluster>(TJsonCluster::GetSwagger()));
+}
+
+void InitViewerLabeledCountersJsonHandler(TJsonHandlers &handlers) {
+    handlers.AddHandler("/viewer/labeledcounters", new TJsonHandler<TJsonLabeledCounters>(TJsonLabeledCounters::GetSwagger()));
+}
+
+void InitViewerTenantsJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/tenants", new TJsonHandler<TJsonTenants>(TJsonTenants::GetSwagger()));
+}
+
+void InitViewerHiveStatsJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/hivestats", new TJsonHandler<TJsonHiveStats>(TJsonHiveStats::GetSwagger()));
+}
+
+void InitViewerTenantInfoJsonHandler(TJsonHandlers &handlers) {
+    handlers.AddHandler("/viewer/tenantinfo", new TJsonHandler<TJsonTenantInfo>(TJsonTenantInfo::GetSwagger()));
+}
+
+void InitViewerWhoAmIJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/whoami", new TJsonHandler<TJsonWhoAmI>(TJsonWhoAmI::GetSwagger()));
+}
+
+void InitViewerQueryJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/query", new TJsonHandler<TJsonQuery>(TJsonQuery::GetSwagger()));
+}
+
+void InitViewerNetInfoJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/netinfo", new TJsonHandler<TJsonNetInfo>(TJsonNetInfo::GetSwagger()));
+}
+
+void InitViewerComputeJsonHandler(TJsonHandlers &handlers) {
+    handlers.AddHandler("/viewer/compute", new TJsonHandler<TJsonCompute>(TJsonCompute::GetSwagger()));
+}
+
+void InitViewerHealthCheckJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/healthcheck", new TJsonHandler<TJsonHealthCheck>(TJsonHealthCheck::GetSwagger()));
+}
+
+void InitViewerNodesJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/nodes", new TJsonHandler<TJsonNodes>(TJsonNodes::GetSwagger()));
+}
+
+void InitViewerACLJsonHandler(TJsonHandlers &jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/acl", new TJsonHandler<TJsonACL>(TJsonACL::GetSwagger()));
+}
+
+void InitViewerGraphJsonHandler(TJsonHandlers &handlers) {
+    handlers.AddHandler("/viewer/graph", new TJsonHandler<TJsonGraph>(TJsonGraph::GetSwagger()));
+}
+
+void InitViewerRenderJsonHandler(TJsonHandlers& handlers) {
+    handlers.AddHandler("/viewer/render", new TJsonHandler<TJsonRender>(TJsonRender::GetSwagger()));
+}
+
+void InitViewerAutocompleteJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/autocomplete", new TJsonHandler<TJsonAutocomplete>(TJsonAutocomplete::GetSwagger()));
+}
+
+void InitViewerCheckAccessJsonHandler(TJsonHandlers& jsonHandlers) {
+    jsonHandlers.AddHandler("/viewer/check_access", new TJsonHandler<TCheckAccess>(TCheckAccess::GetSwagger()));
+}
 
 void InitViewerJsonHandlers(TJsonHandlers& jsonHandlers) {
     InitViewerCapabilitiesJsonHandler(jsonHandlers);
-    jsonHandlers.AddHandler("/viewer/nodelist", new TJsonHandler<TJsonNodeList>);
-    jsonHandlers.AddHandler("/viewer/nodeinfo", new TJsonHandler<TJsonNodeInfo>);
-    jsonHandlers.AddHandler("/viewer/sysinfo", new TJsonHandler<TJsonSysInfo>);
-    jsonHandlers.AddHandler("/viewer/vdiskinfo", new TJsonHandler<TJsonVDiskInfo>);
-    jsonHandlers.AddHandler("/viewer/pdiskinfo", new TJsonHandler<TJsonPDiskInfo>);
-    jsonHandlers.AddHandler("/viewer/tabletinfo", new TJsonHandler<TJsonTabletInfo>);
-    jsonHandlers.AddHandler("/viewer/describe", new TJsonHandler<TJsonDescribe>);
-    jsonHandlers.AddHandler("/viewer/describe_topic", new TJsonHandler<TJsonDescribeTopic>);
-    jsonHandlers.AddHandler("/viewer/describe_consumer", new TJsonHandler<TJsonDescribeConsumer>);
-    jsonHandlers.AddHandler("/viewer/hotkeys", new TJsonHandler<TJsonHotkeys>);
-    jsonHandlers.AddHandler("/viewer/hiveinfo", new TJsonHandler<TJsonHiveInfo>);
-    jsonHandlers.AddHandler("/viewer/bsgroupinfo", new TJsonHandler<TJsonBSGroupInfo>);
-    jsonHandlers.AddHandler("/viewer/bscontrollerinfo", new TJsonHandler<TJsonBSControllerInfo>);
-    jsonHandlers.AddHandler("/viewer/config", new TJsonHandler<TJsonConfig>);
-    jsonHandlers.AddHandler("/viewer/counters", new TJsonHandler<TJsonCounters>);
-    jsonHandlers.AddHandler("/viewer/topicinfo", new TJsonHandler<TJsonTopicInfo>);
-    jsonHandlers.AddHandler("/viewer/pqconsumerinfo", new TJsonHandler<TJsonPQConsumerInfo>);
-    jsonHandlers.AddHandler("/viewer/tabletcounters", new TJsonHandler<TJsonTabletCounters>);
-    jsonHandlers.AddHandler("/viewer/storage", new TJsonHandler<TJsonStorage>);
-    jsonHandlers.AddHandler("/viewer/storage_usage", new TJsonHandler<TJsonStorageUsage>);
-    jsonHandlers.AddHandler("/viewer/metainfo", new TJsonHandler<TJsonMetaInfo>);
-    jsonHandlers.AddHandler("/viewer/browse", new TJsonHandler<TJsonBrowse>);
-    jsonHandlers.AddHandler("/viewer/cluster", new TJsonHandler<TJsonCluster>);
-    jsonHandlers.AddHandler("/viewer/content", new TJsonHandler<TJsonContent>);
-    jsonHandlers.AddHandler("/viewer/labeledcounters", new TJsonHandler<TJsonLabeledCounters>);
-    jsonHandlers.AddHandler("/viewer/tenants", new TJsonHandler<TJsonTenants>);
-    jsonHandlers.AddHandler("/viewer/hivestats", new TJsonHandler<TJsonHiveStats>);
-    jsonHandlers.AddHandler("/viewer/tenantinfo", new TJsonHandler<TJsonTenantInfo>);
-    jsonHandlers.AddHandler("/viewer/whoami", new TJsonHandler<TJsonWhoAmI>);
-    jsonHandlers.AddHandler("/viewer/query", new TJsonHandler<TJsonQuery>);
-    jsonHandlers.AddHandler("/viewer/netinfo", new TJsonHandler<TJsonNetInfo>);
-    jsonHandlers.AddHandler("/viewer/compute", new TJsonHandler<TJsonCompute>);
-    jsonHandlers.AddHandler("/viewer/healthcheck", new TJsonHandler<TJsonHealthCheck>);
-    jsonHandlers.AddHandler("/viewer/nodes", new TJsonHandler<TJsonNodes>);
-    jsonHandlers.AddHandler("/viewer/acl", new TJsonHandler<TJsonACL>);
-    jsonHandlers.AddHandler("/viewer/graph", new TJsonHandler<TJsonGraph>);
-    jsonHandlers.AddHandler("/viewer/render", new TJsonHandler<TJsonRender>);
-    jsonHandlers.AddHandler("/viewer/autocomplete", new TJsonHandler<TJsonAutocomplete>);
-    jsonHandlers.AddHandler("/viewer/check_access", new TJsonHandler<TCheckAccess>);
+    InitViewerNodelistJsonHandler(jsonHandlers);
+    InitViewerNodeInfoJsonHandler(jsonHandlers);
+    InitViewerSysInfoJsonHandler(jsonHandlers);
+    InitViewerVDiskInfoJsonHandler(jsonHandlers);
+    InitViewerPDiskInfoJsonHandler(jsonHandlers);
+    InitViewerTabletInfoJsonHandler(jsonHandlers);
+    InitViewerDescribeJsonHandler(jsonHandlers);
+    InitViewerDescribeTopicJsonHandler(jsonHandlers);
+    InitViewerDescribeConsumerJsonHandler(jsonHandlers);
+    InitViewerHotkeysJsonHandler(jsonHandlers);
+    InitViewerHiveInfoJsonHandler(jsonHandlers);
+    InitViewerBSGroupInfoJsonHandler(jsonHandlers);
+    InitViewerBSControllerInfoJsonHandler(jsonHandlers);
+    InitViewerConfigJsonHandler(jsonHandlers);
+    InitViewerCountersJsonHandler(jsonHandlers);
+    InitViewerTopicInfoJsonHandler(jsonHandlers);
+    InitViewerPQConsumerInfoJsonHandler(jsonHandlers);
+    InitViewerTabletCountersJsonHandler(jsonHandlers);
+    InitViewerStorageJsonHandler(jsonHandlers);
+    InitViewerStorageUsageJsonHandler(jsonHandlers);
+    InitViewerClusterJsonHandler(jsonHandlers);
+    InitViewerLabeledCountersJsonHandler(jsonHandlers);
+    InitViewerTenantsJsonHandler(jsonHandlers);
+    InitViewerHiveStatsJsonHandler(jsonHandlers);
+    InitViewerTenantInfoJsonHandler(jsonHandlers);
+    InitViewerWhoAmIJsonHandler(jsonHandlers);
+    InitViewerQueryJsonHandler(jsonHandlers);
+    InitViewerNetInfoJsonHandler(jsonHandlers);
+    InitViewerComputeJsonHandler(jsonHandlers);
+    InitViewerHealthCheckJsonHandler(jsonHandlers);
+    InitViewerNodesJsonHandler(jsonHandlers);
+    InitViewerACLJsonHandler(jsonHandlers);
+    InitViewerGraphJsonHandler(jsonHandlers);
+    InitViewerRenderJsonHandler(jsonHandlers);
+    InitViewerAutocompleteJsonHandler(jsonHandlers);
+    InitViewerCheckAccessJsonHandler(jsonHandlers);
 }
 
 }
diff --git a/ydb/core/viewer/json_local_rpc.h b/ydb/core/viewer/json_local_rpc.h
index 00cd683cbb72..f8aabfe71ca6 100644
--- a/ydb/core/viewer/json_local_rpc.h
+++ b/ydb/core/viewer/json_local_rpc.h
@@ -1,17 +1,8 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <library/cpp/protobuf/json/json2proto.h>
-#include <library/cpp/json/json_writer.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include "viewer.h"
 #include "json_pipe_req.h"
-
+#include "viewer.h"
+#include <library/cpp/json/json_writer.h>
 #include <ydb/core/grpc_services/local_rpc/local_rpc.h>
-#include <ydb/public/sdk/cpp/client/ydb_types/status/status.h>
 
 namespace NKikimr {
 namespace NViewer {
diff --git a/ydb/core/viewer/json_pipe_req.cpp b/ydb/core/viewer/json_pipe_req.cpp
index b759922719c9..49f683caf101 100644
--- a/ydb/core/viewer/json_pipe_req.cpp
+++ b/ydb/core/viewer/json_pipe_req.cpp
@@ -1,4 +1,5 @@
 #include "json_pipe_req.h"
+#include <library/cpp/json/json_writer.h>
 
 namespace NKikimr::NViewer {
 
@@ -410,6 +411,10 @@ TString TViewerPipeClient::GetHTTPOKJSON(TString response, TInstant lastModified
     return Viewer->GetHTTPOKJSON(GetRequest(), std::move(response), lastModified);
 }
 
+TString TViewerPipeClient::GetHTTPOKJSON(const NJson::TJsonValue& response, TInstant lastModified) {
+    return GetHTTPOKJSON(NJson::WriteJson(response, false), lastModified);
+}
+
 TString TViewerPipeClient::GetHTTPGATEWAYTIMEOUT(TString contentType, TString response) {
     return Viewer->GetHTTPGATEWAYTIMEOUT(GetRequest(), std::move(contentType), std::move(response));
 }
@@ -422,6 +427,10 @@ TString TViewerPipeClient::GetHTTPINTERNALERROR(TString contentType, TString res
     return Viewer->GetHTTPINTERNALERROR(GetRequest(), std::move(contentType), std::move(response));
 }
 
+TString TViewerPipeClient::GetHTTPFORBIDDEN(TString contentType, TString response) {
+    return Viewer->GetHTTPFORBIDDEN(GetRequest(), std::move(contentType), std::move(response));
+}
+
 TString TViewerPipeClient::MakeForward(const std::vector<ui32>& nodes) {
     return Viewer->MakeForward(GetRequest(), nodes);
 }
@@ -443,6 +452,10 @@ void TViewerPipeClient::Handle(TEvTabletPipe::TEvClientConnected::TPtr& ev) {
     }
 }
 
+void TViewerPipeClient::HandleTimeout() {
+    ReplyAndPassAway(GetHTTPGATEWAYTIMEOUT());
+}
+
 void TViewerPipeClient::PassAway() {
     ClosePipes();
     TBase::PassAway();
diff --git a/ydb/core/viewer/json_pipe_req.h b/ydb/core/viewer/json_pipe_req.h
index d7ecd55d6c9c..0ae68e68f277 100644
--- a/ydb/core/viewer/json_pipe_req.h
+++ b/ydb/core/viewer/json_pipe_req.h
@@ -1,28 +1,26 @@
 #pragma once
-
-#include <ydb/library/actors/core/actor.h>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/wilson_ids/wilson.h>
-#include <ydb/library/actors/wilson/wilson_span.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/cms/console/console.h>
+#include "viewer.h"
 #include <ydb/core/base/hive.h>
 #include <ydb/core/base/statestorage.h>
+#include <ydb/core/base/tablet_pipe.h>
 #include <ydb/core/blobstorage/base/blobstorage_events.h>
+#include <ydb/core/cms/console/console.h>
 #include <ydb/core/grpc_services/db_metadata_cache.h>
 #include <ydb/core/node_whiteboard/node_whiteboard.h>
+#include <ydb/core/sys_view/common/events.h>
 #include <ydb/core/tx/scheme_cache/scheme_cache.h>
 #include <ydb/core/tx/schemeshard/schemeshard.h>
 #include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/sys_view/common/events.h>
-#include "viewer.h"
+#include <ydb/library/actors/core/actor_bootstrapped.h>
+#include <ydb/library/actors/wilson/wilson_span.h>
+#include <ydb/library/wilson_ids/wilson.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NKikimr;
 using namespace NSchemeCache;
 using NNodeWhiteboard::TNodeId;
+using NNodeWhiteboard::TTabletId;
 
 class TViewerPipeClient : public TActorBootstrapped<TViewerPipeClient> {
     using TBase = TActorBootstrapped<TViewerPipeClient>;
@@ -50,7 +48,7 @@ class TViewerPipeClient : public TActorBootstrapped<TViewerPipeClient> {
         ui32 Requests = 0;
     };
 
-    std::unordered_map<NNodeWhiteboard::TTabletId, TPipeInfo> PipeInfo;
+    std::unordered_map<TTabletId, TPipeInfo> PipeInfo;
 
     struct TDelayedRequest {
         std::unique_ptr<IEventHandle> Event;
@@ -152,17 +150,11 @@ class TViewerPipeClient : public TActorBootstrapped<TViewerPipeClient> {
     NTabletPipe::TClientConfig GetPipeClientConfig();
 
     ~TViewerPipeClient();
-
     TViewerPipeClient();
-
     TViewerPipeClient(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev);
-
-    TActorId ConnectTabletPipe(NNodeWhiteboard::TTabletId tabletId);
-
+    TActorId ConnectTabletPipe(TTabletId tabletId);
     void SendEvent(std::unique_ptr<IEventHandle> event);
-
     void SendRequest(TActorId recipient, IEventBase* ev, ui32 flags = 0, ui64 cookie = 0, NWilson::TTraceId traceId = {});
-
     void SendRequestToPipe(TActorId pipe, IEventBase* ev, ui64 cookie = 0, NWilson::TTraceId traceId = {});
 
     template<typename TResponse>
@@ -180,109 +172,70 @@ class TViewerPipeClient : public TActorBootstrapped<TViewerPipeClient> {
     }
 
     void SendDelayedRequests();
+    void RequestHiveDomainStats(TTabletId hiveId);
+    void RequestHiveNodeStats(TTabletId hiveId, TPathId pathId);
+    void RequestHiveStorageStats(TTabletId hiveId);
 
-    void RequestHiveDomainStats(NNodeWhiteboard::TTabletId hiveId);
-
-    void RequestHiveNodeStats(NNodeWhiteboard::TTabletId hiveId, TPathId pathId);
-
-    void RequestHiveStorageStats(NNodeWhiteboard::TTabletId hiveId);
-
-    NNodeWhiteboard::TTabletId GetConsoleId() {
+    TTabletId GetConsoleId() {
         return MakeConsoleID();
     }
 
-    TRequestResponse<TEvHive::TEvResponseHiveStorageStats> MakeRequestHiveStorageStats(NNodeWhiteboard::TTabletId hiveId);
+    TTabletId GetBSControllerId() {
+        return MakeBSControllerID();
+    }
 
+    TRequestResponse<TEvHive::TEvResponseHiveStorageStats> MakeRequestHiveStorageStats(TTabletId hiveId);
     void RequestConsoleListTenants();
-
     TRequestResponse<NConsole::TEvConsole::TEvListTenantsResponse> MakeRequestConsoleListTenants();
-
     void RequestConsoleGetTenantStatus(const TString& path);
-
-    NNodeWhiteboard::TTabletId GetBSControllerId() {
-        return MakeBSControllerID();
-    }
-
     void RequestBSControllerConfig();
-
     void RequestBSControllerConfigWithStoragePools();
-
     TRequestResponse<TEvBlobStorage::TEvControllerConfigResponse> MakeRequestBSControllerConfigWithStoragePools();
-
     void RequestBSControllerInfo();
-
     void RequestBSControllerSelectGroups(THolder<TEvBlobStorage::TEvControllerSelectGroups> request);
-
     TRequestResponse<TEvBlobStorage::TEvControllerSelectGroupsResult> MakeRequestBSControllerSelectGroups(THolder<TEvBlobStorage::TEvControllerSelectGroups> request, ui64 cookie = 0);
-
     void RequestBSControllerPDiskRestart(ui32 nodeId, ui32 pdiskId, bool force = false);
-
     void RequestBSControllerVDiskEvict(ui32 groupId, ui32 groupGeneration, ui32 failRealmIdx, ui32 failDomainIdx, ui32 vdiskIdx, bool force = false);
-
     TRequestResponse<NSysView::TEvSysView::TEvGetPDisksResponse> RequestBSControllerPDiskInfo(ui32 nodeId, ui32 pdiskId);
-
     TRequestResponse<NSysView::TEvSysView::TEvGetVSlotsResponse> RequestBSControllerVDiskInfo(ui32 nodeId, ui32 pdiskId);
-
     TRequestResponse<NSysView::TEvSysView::TEvGetGroupsResponse> RequestBSControllerGroups();
-
     TRequestResponse<NSysView::TEvSysView::TEvGetStoragePoolsResponse> RequestBSControllerPools();
-
     TRequestResponse<NSysView::TEvSysView::TEvGetVSlotsResponse> RequestBSControllerVSlots();
-
     TRequestResponse<NSysView::TEvSysView::TEvGetPDisksResponse> RequestBSControllerPDisks();
-
     void RequestBSControllerPDiskUpdateStatus(const NKikimrBlobStorage::TUpdateDriveStatus& driveStatus, bool force = false);
-
     void RequestSchemeCacheNavigate(const TString& path);
-
     void RequestSchemeCacheNavigate(const TPathId& pathId);
-
     TRequestResponse<TEvTxProxySchemeCache::TEvNavigateKeySetResult> MakeRequestSchemeCacheNavigate(const TString& path, ui64 cookie = 0);
-
     TRequestResponse<TEvTxProxySchemeCache::TEvNavigateKeySetResult> MakeRequestSchemeCacheNavigate(TPathId pathId, ui64 cookie = 0);
-
     void RequestTxProxyDescribe(const TString& path);
-
     void RequestStateStorageEndpointsLookup(const TString& path);
-
     void RequestStateStorageMetadataCacheEndpointsLookup(const TString& path);
-
     std::vector<TNodeId> GetNodesFromBoardReply(TEvStateStorage::TEvBoardInfo::TPtr& ev);
-
     void InitConfig(const TCgiParameters& params);
-
     void InitConfig(const TRequestSettings& settings);
-
     void ClosePipes();
-
-    ui32 FailPipeConnect(NNodeWhiteboard::TTabletId tabletId);
+    ui32 FailPipeConnect(TTabletId tabletId);
 
     bool IsLastRequest() const {
         return Requests == 1;
     }
 
     TRequestState GetRequest() const;
-
     void ReplyAndPassAway(TString data, const TString& error = {});
 
     TString GetHTTPOK(TString contentType = {}, TString response = {}, TInstant lastModified = {});
-
     TString GetHTTPOKJSON(TString response = {}, TInstant lastModified = {});
-
+    TString GetHTTPOKJSON(const NJson::TJsonValue& response, TInstant lastModified = {});
     TString GetHTTPGATEWAYTIMEOUT(TString contentType = {}, TString response = {});
-
     TString GetHTTPBADREQUEST(TString contentType = {}, TString response = {});
-
     TString GetHTTPINTERNALERROR(TString contentType = {}, TString response = {});
-
+    TString GetHTTPFORBIDDEN(TString contentType = {}, TString response = {});
     TString MakeForward(const std::vector<ui32>& nodes);
 
     void RequestDone(ui32 requests = 1);
-
     void Handle(TEvTabletPipe::TEvClientConnected::TPtr& ev);
-
+    void HandleTimeout();
     void PassAway() override;
 };
 
 }
-}
diff --git a/ydb/core/viewer/json_storage_base.h b/ydb/core/viewer/json_storage_base.h
index 986127c6e231..1f8616ce6bbc 100644
--- a/ydb/core/viewer/json_storage_base.h
+++ b/ydb/core/viewer/json_storage_base.h
@@ -1,17 +1,11 @@
 #pragma once
-#include <unordered_map>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/protos/node_whiteboard.pb.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
+#include "json_pipe_req.h"
 #include "viewer.h"
+#include "viewer_bsgroupinfo.h"
+#include "viewer_vdiskinfo.h"
+#include "viewer_pdiskinfo.h"
 #include "viewer_helper.h"
-#include "json_pipe_req.h"
-#include "json_vdiskinfo.h"
-#include "json_pdiskinfo.h"
+#include "wb_merge.h"
 
 template<>
 struct std::hash<NKikimrBlobStorage::TVSlotId> {
@@ -31,8 +25,7 @@ struct std::equal_to<NKikimrBlobStorage::TVSlotId> {
     }
 };
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
@@ -104,10 +97,10 @@ class TJsonStorageBase : public TViewerPipeClient {
         TString Erasure;
         ui32 Degraded;
         float Usage;
-        uint64 Used;
-        uint64 Limit;
-        uint64 Read;
-        uint64 Write;
+        ui64 Used;
+        ui64 Limit;
+        ui64 Read;
+        ui64 Write;
 
         TGroupRow()
             : Used(0)
@@ -561,4 +554,3 @@ class TJsonStorageBase : public TViewerPipeClient {
 };
 
 }
-}
diff --git a/ydb/core/viewer/json_vdisk_req.h b/ydb/core/viewer/json_vdisk_req.h
index 09d1ad1ab64b..71ccc636ca7f 100644
--- a/ydb/core/viewer/json_vdisk_req.h
+++ b/ydb/core/viewer/json_vdisk_req.h
@@ -1,18 +1,12 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include "viewer.h"
 #include "json_pipe_req.h"
+#include "viewer.h"
+#include <ydb/core/viewer/yaml/yaml.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
-
 template <typename RequestType, typename ResponseType>
 struct TJsonVDiskRequestHelper  {
     static std::unique_ptr<RequestType> MakeRequest(NMon::TEvHttpInfo::TPtr &, TString *) {
@@ -24,7 +18,6 @@ struct TJsonVDiskRequestHelper  {
     }
 };
 
-
 template <typename RequestType, typename ResponseType>
 class TJsonVDiskRequest : public TViewerPipeClient {
     enum EEv {
@@ -199,10 +192,11 @@ class TJsonVDiskRequest : public TViewerPipeClient {
     void ReplyAndPassAway() override {
         ReplyAndPassAway({});
     }
-};
 
-template <typename RequestType, typename ResponseType>
-struct TJsonRequestParameters<TJsonVDiskRequest<RequestType, ResponseType>> {
+    static YAML::Node GetSchema() {
+        return TProtoToYaml::ProtoToYamlSchema<typename ResponseType::ProtoRecordType>();
+    }
+
     static YAML::Node GetParameters() {
         return YAML::Load(R"___(
             - name: node_id
@@ -251,12 +245,4 @@ struct TJsonRequestParameters<TJsonVDiskRequest<RequestType, ResponseType>> {
     }
 };
 
-template <typename RequestType, typename ResponseType>
-struct TJsonRequestSchema<TJsonVDiskRequest<RequestType, ResponseType>> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<typename ResponseType::ProtoRecordType>();
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_vdiskstat.h b/ydb/core/viewer/json_vdiskstat.h
deleted file mode 100644
index 8aaa81ed1a9d..000000000000
--- a/ydb/core/viewer/json_vdiskstat.h
+++ /dev/null
@@ -1,30 +0,0 @@
-#pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/util/tuples.h>
-#include "json_vdisk_req.h"
-
-namespace NKikimr {
-namespace NViewer {
-
-using TJsonVDiskStat = TJsonVDiskRequest<TEvVDiskStatRequest, TEvVDiskStatResponse>;
-
-template <>
-struct TJsonRequestSummary<TJsonVDiskStat> {
-    static TString GetSummary() {
-        return "VDisk statistic";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonVDiskStat> {
-    static TString GetDescription() {
-        return "VDisk statistic";
-    }
-};
-
-}
-}
diff --git a/ydb/core/viewer/json_wb_req.cpp b/ydb/core/viewer/json_wb_req.cpp
new file mode 100644
index 000000000000..cb430846abc8
--- /dev/null
+++ b/ydb/core/viewer/json_wb_req.cpp
@@ -0,0 +1,226 @@
+#include "viewer_bsgroupinfo.h"
+#include "viewer_nodeinfo.h"
+#include "viewer_pdiskinfo.h"
+#include "viewer_sysinfo.h"
+#include "viewer_tabletinfo.h"
+#include "viewer_vdiskinfo.h"
+#include "json_handlers.h"
+
+namespace NKikimr::NViewer {
+
+YAML::Node GetWhiteboardRequestParameters() {
+    return YAML::Load(R"___(
+            - name: node_id
+              in: query
+              description: node identifier
+              required: false
+              type: integer
+            - name: merge
+              in: query
+              description: merge information from nodes
+              required: false
+              type: boolean
+            - name: group
+              in: query
+              description: group information by field
+              required: false
+              type: string
+            - name: all
+              in: query
+              description: return all possible key combinations (for enums only)
+              required: false
+              type: boolean
+            - name: filter
+              in: query
+              description: filter information by field
+              required: false
+              type: string
+            - name: alive
+              in: query
+              description: request from alive (connected) nodes only
+              required: false
+              type: boolean
+            - name: enums
+              in: query
+              description: convert enums to strings
+              required: false
+              type: boolean
+            - name: ui64
+              in: query
+              description: return ui64 as number
+              required: false
+              type: boolean
+            - name: timeout
+              in: query
+              description: timeout in ms
+              required: false
+              type: integer
+            - name: retries
+              in: query
+              description: number of retries
+              required: false
+              type: integer
+            - name: retry_period
+              in: query
+              description: retry period in ms
+              required: false
+              type: integer
+              default: 500
+            - name: static
+              in: query
+              description: request from static nodes only
+              required: false
+              type: boolean
+            - name: since
+              in: query
+              description: filter by update time
+              required: false
+              type: string
+            )___");
+}
+
+void InitViewerBSGroupInfoJsonHandler(TJsonHandlers& jsonHandlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "viewer",
+        .Summary = "Storage groups information",
+        .Description = "Returns information about storage groups"
+    });
+    yaml.SetParameters(GetWhiteboardRequestParameters());
+    yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TJsonBSGroupInfo::TResponseType>());
+    jsonHandlers.AddHandler("/viewer/bsgroupinfo", new TJsonHandler<TJsonBSGroupInfo>(yaml));
+    TWhiteboardInfo<NKikimrWhiteboard::TEvBSGroupStateResponse>::InitMerger();
+}
+
+void InitViewerNodeInfoJsonHandler(TJsonHandlers& jsonHandlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "viewer",
+        .Summary = "Interconnect information",
+        .Description = "Returns information about node connections"
+    });
+    yaml.SetParameters(GetWhiteboardRequestParameters());
+    yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TJsonNodeInfo::TResponseType>());
+    jsonHandlers.AddHandler("/viewer/nodeinfo", new TJsonHandler<TJsonNodeInfo>(yaml));
+    TWhiteboardInfo<NKikimrWhiteboard::TEvNodeStateResponse>::InitMerger();
+}
+
+void InitViewerPDiskInfoJsonHandler(TJsonHandlers& jsonHandlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "viewer",
+        .Summary = "PDisk information",
+        .Description = "Returns information about PDisks"
+    });
+    yaml.SetParameters(GetWhiteboardRequestParameters());
+    yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TJsonPDiskInfo::TResponseType>());
+    jsonHandlers.AddHandler("/viewer/pdiskinfo", new TJsonHandler<TJsonPDiskInfo>(yaml));
+}
+
+void InitViewerSysInfoJsonHandler(TJsonHandlers& jsonHandlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "viewer",
+        .Summary = "System information",
+        .Description = "Returns system information"
+    });
+    yaml.SetParameters(GetWhiteboardRequestParameters());
+    yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TJsonSysInfo::TResponseType>());
+    jsonHandlers.AddHandler("/viewer/sysinfo", new TJsonHandler<TJsonSysInfo>(yaml));
+}
+
+void InitViewerTabletInfoJsonHandler(TJsonHandlers& jsonHandlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "viewer",
+        .Summary = "Tablet information",
+        .Description = "Returns information about tablets"
+    });
+    yaml.AddParameter({
+        .Name = "node_id",
+        .Description = "node identifier",
+        .Type = "integer",
+    });
+    yaml.AddParameter({
+        .Name = "path",
+        .Description = "schema path",
+        .Type = "string",
+    });
+    yaml.AddParameter({
+        .Name = "merge",
+        .Description = "merge information from nodes",
+        .Type = "boolean",
+    });
+    yaml.AddParameter({
+        .Name = "group",
+        .Description = "group information by field",
+        .Type = "string",
+    });
+    yaml.AddParameter({
+        .Name = "all",
+        .Description = "return all possible key combinations (for enums only)",
+        .Type = "boolean",
+    });
+    yaml.AddParameter({
+        .Name = "filter",
+        .Description = "filter information by field",
+        .Type = "string",
+    });
+    yaml.AddParameter({
+        .Name = "alive",
+        .Description = "request from alive (connected) nodes only",
+        .Type = "boolean",
+    });
+    yaml.AddParameter({
+        .Name = "enums",
+        .Description = "convert enums to strings",
+        .Type = "boolean",
+    });
+    yaml.AddParameter({
+        .Name = "ui64",
+        .Description = "return ui64 as number",
+        .Type = "boolean",
+    });
+    yaml.AddParameter({
+        .Name = "timeout",
+        .Description = "timeout in ms",
+        .Type = "integer",
+    });
+    yaml.AddParameter({
+        .Name = "retries",
+        .Description = "number of retries",
+        .Type = "integer",
+    });
+    yaml.AddParameter({
+        .Name = "retry_period",
+        .Description = "retry period in ms",
+        .Type = "integer",
+        .Default = "500",
+    });
+    yaml.AddParameter({
+        .Name = "static",
+        .Description = "request from static nodes only",
+        .Type = "boolean",
+    });
+    yaml.AddParameter({
+        .Name = "since",
+        .Description = "filter by update time",
+        .Type = "string",
+    });
+    yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TJsonTabletInfo::TResponseType>());
+    jsonHandlers.AddHandler("/viewer/tabletinfo", new TJsonHandler<TJsonTabletInfo>(yaml));
+}
+
+void InitViewerVDiskInfoJsonHandler(TJsonHandlers& jsonHandlers) {
+    TSimpleYamlBuilder yaml({
+        .Method = "get",
+        .Tag = "viewer",
+        .Summary = "VDisk information",
+        .Description = "Returns information about VDisks"
+    });
+    yaml.SetParameters(GetWhiteboardRequestParameters());
+    yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TJsonVDiskInfo::TResponseType>());
+    jsonHandlers.AddHandler("/viewer/vdiskinfo", new TJsonHandler<TJsonVDiskInfo>(yaml));
+}
+
+}
diff --git a/ydb/core/viewer/json_wb_req.h b/ydb/core/viewer/json_wb_req.h
index 03bc949d4ebf..235b8e52eeec 100644
--- a/ydb/core/viewer/json_wb_req.h
+++ b/ydb/core/viewer/json_wb_req.h
@@ -1,28 +1,26 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/library/actors/interconnect/interconnect.h>
-#include "viewer.h"
 #include "json_pipe_req.h"
-#include "wb_merge.h"
-#include "wb_group.h"
+#include "log.h"
+#include "viewer.h"
 #include "wb_filter.h"
+#include "wb_group.h"
+#include "wb_merge.h"
 #include "wb_req.h"
-#include "log.h"
+#include <ydb/core/node_whiteboard/node_whiteboard.h>
+#include <ydb/core/viewer/json/json.h>
+#include <ydb/core/viewer/yaml/yaml.h>
+#include <ydb/library/actors/interconnect/interconnect.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
 
+YAML::Node GetWhiteboardRequestParameters();
+
 template<typename TRequestEventType, typename TResponseEventType>
 class TJsonWhiteboardRequest : public TWhiteboardRequest<TRequestEventType, TResponseEventType> {
-protected:
+public:
     using TThis = TJsonWhiteboardRequest<TRequestEventType, TResponseEventType>;
     using TBase = TWhiteboardRequest<TRequestEventType, TResponseEventType>;
     using TResponseType = typename TResponseEventType::ProtoRecordType;
@@ -30,7 +28,6 @@ class TJsonWhiteboardRequest : public TWhiteboardRequest<TRequestEventType, TRes
     NMon::TEvHttpInfo::TPtr Event;
     TJsonSettings JsonSettings;
 
-public:
     static constexpr NKikimrServices::TActivity::EType ActorActivityType() {
         return NKikimrServices::TActivity::VIEWER_HANDLER;
     }
@@ -131,86 +128,4 @@ class TJsonWhiteboardRequest : public TWhiteboardRequest<TRequestEventType, TRes
     }
 };
 
-template <typename RequestType, typename ResponseType>
-struct TJsonRequestParameters<TJsonWhiteboardRequest<RequestType, ResponseType>> {
-    static YAML::Node GetParameters() {
-            return YAML::Load(R"___(
-                    - name: node_id
-                      in: query
-                      description: node identifier
-                      required: false
-                      type: integer
-                    - name: merge
-                      in: query
-                      description: merge information from nodes
-                      required: false
-                      type: boolean
-                    - name: group
-                      in: query
-                      description: group information by field
-                      required: false
-                      type: string
-                    - name: all
-                      in: query
-                      description: return all possible key combinations (for enums only)
-                      required: false
-                      type: boolean
-                    - name: filter
-                      in: query
-                      description: filter information by field
-                      required: false
-                      type: string
-                    - name: alive
-                      in: query
-                      description: request from alive (connected) nodes only
-                      required: false
-                      type: boolean
-                    - name: enums
-                      in: query
-                      description: convert enums to strings
-                      required: false
-                      type: boolean
-                    - name: ui64
-                      in: query
-                      description: return ui64 as number
-                      required: false
-                      type: boolean
-                    - name: timeout
-                      in: query
-                      description: timeout in ms
-                      required: false
-                      type: integer
-                    - name: retries
-                      in: query
-                      description: number of retries
-                      required: false
-                      type: integer
-                    - name: retry_period
-                      in: query
-                      description: retry period in ms
-                      required: false
-                      type: integer
-                      default: 500
-                    - name: static
-                      in: query
-                      description: request from static nodes only
-                      required: false
-                      type: boolean
-                    - name: since
-                      in: query
-                      description: filter by update time
-                      required: false
-                      type: string
-            )___");
-    }
-};
-
-template <typename RequestType, typename ResponseType>
-struct TJsonRequestSchema<TJsonWhiteboardRequest<RequestType, ResponseType>> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<typename ResponseType::ProtoRecordType>();
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/log.h b/ydb/core/viewer/log.h
index 8a0fe6dcf054..da5229ff0c68 100644
--- a/ydb/core/viewer/log.h
+++ b/ydb/core/viewer/log.h
@@ -1,16 +1,13 @@
 #pragma once
-
-#include <ydb/library/services/services.pb.h>
 #include <ydb/library/actors/core/log.h>
+#include <ydb/library/services/services.pb.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 inline TString GetLogPrefix() {
     return {};
 }
 
-}
 }
 
 #define BLOG_D(stream) LOG_DEBUG_S(*TlsActivationContext, NKikimrServices::VIEWER, GetLogPrefix() << stream)
diff --git a/ydb/core/viewer/operation_cancel.h b/ydb/core/viewer/operation_cancel.h
index eea1a238bb88..dc55fc145fdb 100644
--- a/ydb/core/viewer/operation_cancel.h
+++ b/ydb/core/viewer/operation_cancel.h
@@ -1,10 +1,10 @@
 #pragma once
-#include <ydb/public/api/grpc/ydb_operation_v1.grpc.pb.h>
-#include <ydb/core/grpc_services/rpc_calls.h>
 #include "json_local_rpc.h"
+#include <ydb/core/grpc_services/rpc_calls.h>
+#include <ydb/core/viewer/yaml/yaml.h>
+#include <ydb/public/api/grpc/ydb_operation_v1.grpc.pb.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using TOperationCancelRpc = TJsonLocalRpc<Ydb::Operations::CancelOperationRequest,
                                           Ydb::Operations::CancelOperationResponse,
@@ -48,51 +48,50 @@ class TOperationCancel : public TOperationCancelRpc {
 
         TBase::Bootstrap();
     }
-};
 
-template<>
-YAML::Node TJsonRequestSwagger<TOperationCancel>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
         post:
-          tags:
-          - operation
-          summary: Cancels operation
-          description: >
-            Starts cancellation of a long-running operation,
-            Clients can use GetOperation to check whether the cancellation succeeded
-            or whether the operation completed despite cancellation.
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: id
-            in: query
-            description: operation id
-            required: true
-            type: string
-          requestBody:
-            content:
-              application/json:
-                schema: {}
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-    node["post"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::CancelOperationResponse>();
-    node["post"]["requestBody"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::CancelOperationRequest>();
-    return node;
-}
+            tags:
+              - operation
+            summary: Cancels operation
+            description: >
+                Starts cancellation of a long-running operation,
+                Clients can use GetOperation to check whether the cancellation succeeded
+                or whether the operation completed despite cancellation.
+            parameters:
+              - name: database
+                in: query
+                description: database name
+                required: true
+                type: string
+              - name: id
+                in: query
+                description: operation id
+                required: true
+                type: string
+            requestBody:
+                content:
+                    application/json:
+                        schema: {}
+            responses:
+                200:
+                    description: OK
+                    content:
+                        application/json:
+                            schema: {}
+                400:
+                    description: Bad Request
+                403:
+                    description: Forbidden
+                504:
+                    description: Gateway Timeout
+            )___");
+        node["post"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::CancelOperationResponse>();
+        node["post"]["requestBody"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::CancelOperationRequest>();
+        return node;
+    }
+};
 
 }
-}
+
diff --git a/ydb/core/viewer/operation_forget.h b/ydb/core/viewer/operation_forget.h
index b8338ae78409..2ba961755530 100644
--- a/ydb/core/viewer/operation_forget.h
+++ b/ydb/core/viewer/operation_forget.h
@@ -1,10 +1,10 @@
 #pragma once
-#include <ydb/public/api/grpc/ydb_operation_v1.grpc.pb.h>
-#include <ydb/core/grpc_services/rpc_calls.h>
 #include "json_local_rpc.h"
+#include <ydb/core/grpc_services/rpc_calls.h>
+#include <ydb/core/viewer/yaml/yaml.h>
+#include <ydb/public/api/grpc/ydb_operation_v1.grpc.pb.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using TOperationForgetRpc = TJsonLocalRpc<Ydb::Operations::ForgetOperationRequest,
                                           Ydb::Operations::ForgetOperationResponse,
@@ -48,50 +48,48 @@ class TOperationForget : public TOperationForgetRpc {
 
         TBase::Bootstrap();
     }
-};
 
-template<>
-YAML::Node TJsonRequestSwagger<TOperationForget>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        post:
-          tags:
-          - operation
-          summary: Forgets operation
-          description: >
-            Forgets long-running operation. It does not cancel the operation and returns
-            an error if operation was not completed.
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: id
-            in: query
-            description: operation id
-            required: true
-            type: string
-          requestBody:
-            content:
-              application/json:
-                schema: {}
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-    node["post"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::ForgetOperationResponse>();
-    node["post"]["requestBody"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::ForgetOperationRequest>();
-    return node;
-}
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
+            post:
+                tags:
+                  - operation
+                summary: Forgets operation
+                description: >
+                    Forgets long-running operation. It does not cancel the operation and returns
+                    an error if operation was not completed.
+                parameters:
+                  - name: database
+                    in: query
+                    description: database name
+                    required: true
+                    type: string
+                  - name: id
+                    in: query
+                    description: operation id
+                    required: true
+                    type: string
+                requestBody:
+                    content:
+                        application/json:
+                            schema: {}
+                responses:
+                    200:
+                        description: OK
+                        content:
+                            application/json:
+                                schema: {}
+                    400:
+                        description: Bad Request
+                    403:
+                        description: Forbidden
+                    504:
+                        description: Gateway Timeout
+            )___");
+        node["post"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::ForgetOperationResponse>();
+        node["post"]["requestBody"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::ForgetOperationRequest>();
+        return node;
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/operation_get.h b/ydb/core/viewer/operation_get.h
index 5fd4a0b61f4c..3b9ffeb4b48f 100644
--- a/ydb/core/viewer/operation_get.h
+++ b/ydb/core/viewer/operation_get.h
@@ -1,10 +1,10 @@
 #pragma once
-#include <ydb/public/api/grpc/ydb_operation_v1.grpc.pb.h>
-#include <ydb/core/grpc_services/rpc_calls.h>
 #include "json_local_rpc.h"
+#include <ydb/core/grpc_services/rpc_calls.h>
+#include <ydb/core/viewer/yaml/yaml.h>
+#include <ydb/public/api/grpc/ydb_operation_v1.grpc.pb.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using TOperationGetRpc = TJsonLocalRpc<Ydb::Operations::GetOperationRequest,
                                        Ydb::Operations::GetOperationResponse,
@@ -39,43 +39,41 @@ class TOperationGet : public TOperationGetRpc {
 
         TBase::Bootstrap();
     }
-};
 
-template<>
-YAML::Node TJsonRequestSwagger<TOperationGet>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        get:
-          tags:
-          - operation
-          summary: Get operation
-          description: Check status for a given operation
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: id
-            in: query
-            description: operation id
-            required: true
-            type: string
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-    node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::Operation>();
-    return node;
-}
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
+            get:
+                tags:
+                  - operation
+                summary: Get operation
+                description: Check status for a given operation
+                parameters:
+                  - name: database
+                    in: query
+                    description: database name
+                    required: true
+                    type: string
+                  - name: id
+                    in: query
+                    description: operation id
+                    required: true
+                    type: string
+                responses:
+                    200:
+                        description: OK
+                        content:
+                            application/json:
+                                schema: {}
+                    400:
+                        description: Bad Request
+                    403:
+                        description: Forbidden
+                    504:
+                        description: Gateway Timeout
+            )___");
+        node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::Operation>();
+        return node;
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/operation_list.h b/ydb/core/viewer/operation_list.h
index e78b59188101..585f1812c17d 100644
--- a/ydb/core/viewer/operation_list.h
+++ b/ydb/core/viewer/operation_list.h
@@ -1,10 +1,10 @@
 #pragma once
-#include <ydb/public/api/grpc/ydb_operation_v1.grpc.pb.h>
-#include <ydb/core/grpc_services/rpc_calls.h>
 #include "json_local_rpc.h"
+#include <ydb/core/grpc_services/rpc_calls.h>
+#include <ydb/core/viewer/yaml/yaml.h>
+#include <ydb/public/api/grpc/ydb_operation_v1.grpc.pb.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using TOperationListRpc = TJsonLocalRpc<Ydb::Operations::ListOperationsRequest,
                                         Ydb::Operations::ListOperationsResponse,
@@ -47,57 +47,55 @@ class TOperationList : public TOperationListRpc {
 
         TBase::Bootstrap();
     }
-};
 
-template<>
-YAML::Node TJsonRequestSwagger<TOperationList>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        get:
-          tags:
-          - operation
-          summary: List operations
-          description: Lists operations that match the specified filter in the request
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: kind
-            in: query
-            description: kind
-            required: true
-            type: string
-          - name: page_size
-            in: query
-            description: page size
-            required: false
-            type: integer
-          - name: page_token
-            in: query
-            description: page token
-            required: false
-            type: string
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-    node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::ListOperationsResponse>();
-    TProtoToYaml::FillEnum(node["get"]["parameters"][1]["enum"], NProtoBuf::GetEnumDescriptor<Ydb::TOperationId::EKind>(), {
-        .ConvertToLowerCase = true,
-        .SkipDefaultValue = true
-    });
-    return node;
-}
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
+            get:
+                tags:
+                  - operation
+                summary: List operations
+                description: Lists operations that match the specified filter in the request
+                parameters:
+                  - name: database
+                    in: query
+                    description: database name
+                    required: true
+                    type: string
+                  - name: kind
+                    in: query
+                    description: kind
+                    required: true
+                    type: string
+                  - name: page_size
+                    in: query
+                    description: page size
+                    required: false
+                    type: integer
+                  - name: page_token
+                    in: query
+                    description: page token
+                    required: false
+                    type: string
+                responses:
+                    200:
+                        description: OK
+                        content:
+                            application/json:
+                                schema: {}
+                    400:
+                        description: Bad Request
+                    403:
+                        description: Forbidden
+                    504:
+                        description: Gateway Timeout
+            )___");
+        node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Operations::ListOperationsResponse>();
+        TProtoToYaml::FillEnum(node["get"]["parameters"][1]["enum"], NProtoBuf::GetEnumDescriptor<Ydb::TOperationId::EKind>(), {
+            .ConvertToLowerCase = true,
+            .SkipDefaultValue = true
+        });
+        return node;
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/pdisk_info.h b/ydb/core/viewer/pdisk_info.h
index 844f939275da..78b105f6b891 100644
--- a/ydb/core/viewer/pdisk_info.h
+++ b/ydb/core/viewer/pdisk_info.h
@@ -1,17 +1,9 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/viewer/yaml/yaml.h>
-#include <ydb/core/util/wildcard.h>
-#include <library/cpp/json/json_writer.h>
-#include "viewer.h"
 #include "json_pipe_req.h"
+#include "viewer.h"
+#include <ydb/core/viewer/yaml/yaml.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -231,53 +223,51 @@ class TPDiskInfo : public TViewerPipeClient {
         });
         TBase::ReplyAndPassAway(GetHTTPOKJSON(json.Str()));
     }
-};
 
-template <>
-YAML::Node TJsonRequestSwagger<TPDiskInfo>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        get:
-          tags:
-          - pdisk
-          summary: Gets PDisk info
-          description: Gets PDisk information from Whiteboard and BSC
-          parameters:
-          - name: node_id
-            in: query
-            description: node identifier
-            type: integer
-          - name: pdisk_id
-            in: query
-            description: pdisk identifier
-            required: true
-            type: integer
-          - name: timeout
-            in: query
-            description: timeout in ms
-            required: false
-            type: integer
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-
-    node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TPDiskInfo>();
-    YAML::Node properties(node["get"]["responses"]["200"]["content"]["application/json"]["schema"]["properties"]["BSC"]["properties"]);
-    TProtoToYaml::FillEnum(properties["PDisk"]["properties"]["StatusV2"], NProtoBuf::GetEnumDescriptor<NKikimrBlobStorage::EDriveStatus>());
-    TProtoToYaml::FillEnum(properties["PDisk"]["properties"]["DecommitStatus"], NProtoBuf::GetEnumDescriptor<NKikimrBlobStorage::EDecommitStatus>());
-    TProtoToYaml::FillEnum(properties["PDisk"]["properties"]["Type"], NProtoBuf::GetEnumDescriptor<NKikimrBlobStorage::EPDiskType>());
-    TProtoToYaml::FillEnum(properties["VDisks"]["items"]["properties"]["StatusV2"], NProtoBuf::GetEnumDescriptor<NKikimrBlobStorage::EVDiskStatus>());
-    return node;
-}
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
+          get:
+            tags:
+            - pdisk
+            summary: Gets PDisk info
+            description: Gets PDisk information from Whiteboard and BSC
+            parameters:
+            - name: node_id
+              in: query
+              description: node identifier
+              type: integer
+            - name: pdisk_id
+              in: query
+              description: pdisk identifier
+              required: true
+              type: integer
+            - name: timeout
+              in: query
+              description: timeout in ms
+              required: false
+              type: integer
+            responses:
+              200:
+                description: OK
+                content:
+                  application/json:
+                    schema: {}
+              400:
+                description: Bad Request
+              403:
+                description: Forbidden
+              504:
+                description: Gateway Timeout
+            )___");
+
+        node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TPDiskInfo>();
+        YAML::Node properties(node["get"]["responses"]["200"]["content"]["application/json"]["schema"]["properties"]["BSC"]["properties"]);
+        TProtoToYaml::FillEnum(properties["PDisk"]["properties"]["StatusV2"], NProtoBuf::GetEnumDescriptor<NKikimrBlobStorage::EDriveStatus>());
+        TProtoToYaml::FillEnum(properties["PDisk"]["properties"]["DecommitStatus"], NProtoBuf::GetEnumDescriptor<NKikimrBlobStorage::EDecommitStatus>());
+        TProtoToYaml::FillEnum(properties["PDisk"]["properties"]["Type"], NProtoBuf::GetEnumDescriptor<NKikimrBlobStorage::EPDiskType>());
+        TProtoToYaml::FillEnum(properties["VDisks"]["items"]["properties"]["StatusV2"], NProtoBuf::GetEnumDescriptor<NKikimrBlobStorage::EVDiskStatus>());
+        return node;
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/json_pdisk_restart.h b/ydb/core/viewer/pdisk_restart.h
similarity index 71%
rename from ydb/core/viewer/json_pdisk_restart.h
rename to ydb/core/viewer/pdisk_restart.h
index ff92e7011a63..440a4429a082 100644
--- a/ydb/core/viewer/json_pdisk_restart.h
+++ b/ydb/core/viewer/pdisk_restart.h
@@ -1,16 +1,10 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/util/wildcard.h>
-#include <library/cpp/json/json_writer.h>
-#include "viewer.h"
 #include "json_pipe_req.h"
+#include "viewer.h"
+#include <library/cpp/json/json_writer.h>
+#include <ydb/core/viewer/yaml/yaml.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -161,61 +155,60 @@ class TJsonPDiskRestart : public TViewerPipeClient {
         }
         PassAway();
     }
-};
 
-template <>
-YAML::Node TJsonRequestSwagger<TJsonPDiskRestart>::GetSwagger() {
-    return YAML::Load(R"___(
-        post:
-          tags:
-          - pdisk
-          summary: Restart PDisk
-          description: Restart PDisk on the specified node
-          parameters:
-          - name: node_id
-            in: query
-            description: node identifier
-            type: integer
-          - name: pdisk_id
-            in: query
-            description: pdisk identifier
-            required: true
-            type: integer
-          - name: timeout
-            in: query
-            description: timeout in ms
-            required: false
-            type: integer
-          - name: force
-            in: query
-            description: attempt forced operation, ignore warnings
-            required: false
-            type: boolean
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema:
-                    type: object
-                    properties:
-                      result:
-                        type: boolean
-                        description: was operation successful or not
-                      error:
-                        type: string
-                        description: details about failed operation
-                      forceRetryPossible:
-                        type: boolean
-                        description: if true, operation can be retried with force flag
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-}
+    static YAML::Node GetSwagger() {
+        return YAML::Load(R"___(
+            post:
+                tags:
+                  - pdisk
+                summary: Restart PDisk
+                description: Restart PDisk on the specified node
+                parameters:
+                  - name: node_id
+                    in: query
+                    description: node identifier
+                    type: integer
+                  - name: pdisk_id
+                    in: query
+                    description: pdisk identifier
+                    required: true
+                    type: integer
+                  - name: timeout
+                    in: query
+                    description: timeout in ms
+                    required: false
+                    type: integer
+                  - name: force
+                    in: query
+                    description: attempt forced operation, ignore warnings
+                    required: false
+                    type: boolean
+                responses:
+                    200:
+                        description: OK
+                        content:
+                            application/json:
+                                schema:
+                                    type: object
+                                    properties:
+                                    result:
+                                        type: boolean
+                                        description: was operation successful or not
+                                    error:
+                                        type: string
+                                        description: details about failed operation
+                                    forceRetryPossible:
+                                        type: boolean
+                                        description: if true, operation can be retried with force flag
+                    400:
+                        description: Bad Request
+                    403:
+                        description: Forbidden
+                    504:
+                        description: Gateway Timeout
+            )___");
+    }
+
+};
 
-}
 }
diff --git a/ydb/core/viewer/pdisk_status.h b/ydb/core/viewer/pdisk_status.h
index 783d7a7f1db7..a8330716ef46 100644
--- a/ydb/core/viewer/pdisk_status.h
+++ b/ydb/core/viewer/pdisk_status.h
@@ -1,17 +1,10 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/viewer/yaml/yaml.h>
-#include <ydb/core/util/wildcard.h>
-#include <library/cpp/json/json_writer.h>
-#include "viewer.h"
 #include "json_pipe_req.h"
+#include "viewer.h"
+#include <library/cpp/json/json_writer.h>
+#include <ydb/core/viewer/yaml/yaml.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 extern bool IsPostContent(const NMon::TEvHttpInfo::TPtr& event);
@@ -154,89 +147,87 @@ class TPDiskStatus : public TViewerPipeClient {
         }
         PassAway();
     }
-};
 
-template <>
-YAML::Node TJsonRequestSwagger<TPDiskStatus>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
         post:
-          tags:
-          - pdisk
-          summary: Updates PDisk status
-          description: Updates PDisk status in BSC
-          parameters:
-          - name: node_id
-            in: query
-            description: node identifier
-            type: integer
-          - name: pdisk_id
-            in: query
-            description: pdisk identifier
-            required: true
-            type: integer
-          - name: timeout
-            in: query
-            description: timeout in ms
-            required: false
-            type: integer
-          - name: force
-            in: query
-            description: attempt forced operation, ignore warnings
-            required: false
-            type: boolean
-          requestBody:
-            description: Updates of PDisk statuses
-            required: true
-            content:
-              application/json:
-                schema:
-                  type: object
-                  properties:
-                    status:
-                      type: string
-                      enum: [ACTIVE, INACTIVE, BROKEN, FAULTY, TO_BE_REMOVED, UNKNOWN]
-                      description: >
-                        PDisk operational status:
-                         * `ACTIVE` - working as expected
-                         * `INACTIVE` - new groups are not created using this drive, but existing ones continue to work as expected
-                         * `BROKEN` - drive is marked as not working, groups will be immediately moved out of this drive upon receiving this status
-                         * `FAULTY` - drive is expected to become BROKEN soon, new groups are not created, old groups are asynchronously moved out from this drive
-                         * `TO_BE_REMOVED` - same as INACTIVE, but drive is counted in fault model as not working
-                    decommit_status:
-                      type: string
-                      enum: [DECOMMIT_NONE, DECOMMIT_PENDING, DECOMMIT_IMMINENT, DECOMMIT_REJECTED]
-                      description: >
-                        PDisk decommission status:
-                         * `DECOMMIT_NONE` - disk is not in decomission state
-                         * `DECOMMIT_PENDING` - decomission is planned for this disk, but not started yet. existing slots are not moved from the disk, but no new slots are allocated on it
-                         * `DECOMMIT_IMMINENT` - decomission has started for this disk. existing slots are moved from the disk
-                         * `DECOMMIT_REJECTED` - no slots from other disks are placed on this disk in the process of decommission
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema:
-                    type: object
-                    properties:
-                      result:
-                        type: boolean
-                        description: was operation successful or not
-                      error:
-                        type: string
-                        description: details about failed operation
-                      forceRetryPossible:
-                        type: boolean
-                        description: if true, operation can be retried with force flag
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-    return node;
-}
+            tags:
+              - pdisk
+            summary: Updates PDisk status
+            description: Updates PDisk status in BSC
+            parameters:
+              - name: node_id
+                in: query
+                description: node identifier
+                type: integer
+              - name: pdisk_id
+                in: query
+                description: pdisk identifier
+                required: true
+                type: integer
+              - name: timeout
+                in: query
+                description: timeout in ms
+                required: false
+                type: integer
+              - name: force
+                in: query
+                description: attempt forced operation, ignore warnings
+                required: false
+                type: boolean
+            requestBody:
+                description: Updates of PDisk statuses
+                required: true
+                content:
+                    application/json:
+                        schema:
+                            type: object
+                            properties:
+                                status:
+                                    type: string
+                                    enum: [ACTIVE, INACTIVE, BROKEN, FAULTY, TO_BE_REMOVED, UNKNOWN]
+                                    description: >
+                                        PDisk operational status:
+                                        * `ACTIVE` - working as expected
+                                        * `INACTIVE` - new groups are not created using this drive, but existing ones continue to work as expected
+                                        * `BROKEN` - drive is marked as not working, groups will be immediately moved out of this drive upon receiving this status
+                                        * `FAULTY` - drive is expected to become BROKEN soon, new groups are not created, old groups are asynchronously moved out from this drive
+                                        * `TO_BE_REMOVED` - same as INACTIVE, but drive is counted in fault model as not working
+                                decommit_status:
+                                    type: string
+                                    enum: [DECOMMIT_NONE, DECOMMIT_PENDING, DECOMMIT_IMMINENT, DECOMMIT_REJECTED]
+                                    description: >
+                                        PDisk decommission status:
+                                        * `DECOMMIT_NONE` - disk is not in decomission state
+                                        * `DECOMMIT_PENDING` - decomission is planned for this disk, but not started yet. existing slots are not moved from the disk, but no new slots are allocated on it
+                                        * `DECOMMIT_IMMINENT` - decomission has started for this disk. existing slots are moved from the disk
+                                        * `DECOMMIT_REJECTED` - no slots from other disks are placed on this disk in the process of decommission
+            responses:
+                200:
+                    description: OK
+                    content:
+                        application/json:
+                            schema:
+                                type: object
+                                properties:
+                                result:
+                                    type: boolean
+                                    description: was operation successful or not
+                                error:
+                                    type: string
+                                    description: details about failed operation
+                                forceRetryPossible:
+                                    type: boolean
+                                    description: if true, operation can be retried with force flag
+                400:
+                    description: Bad Request
+                403:
+                    description: Forbidden
+                504:
+                    description: Gateway Timeout
+            )___");
+        return node;
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/protos/viewer.proto b/ydb/core/viewer/protos/viewer.proto
index 0232a1b03fbf..ba88f0b2db0d 100644
--- a/ydb/core/viewer/protos/viewer.proto
+++ b/ydb/core/viewer/protos/viewer.proto
@@ -638,18 +638,17 @@ message TEvDescribeSchemeInfo {
         Cache = 2;
     }
 
-    optional string Status = 1;
-    optional string Reason = 2;
-    optional string Path = 3;
-    optional NKikimrSchemeOp.TPathDescription PathDescription = 4;
-    optional fixed64 DEPRECATED_PathOwner = 5;  // replaced by PathOwnerId
-    optional fixed64 PathId = 6;
-
-    optional string LastExistedPrefixPath = 7;
-    optional fixed64 LastExistedPrefixPathId = 8;
-    optional NKikimrSchemeOp.TPathDescription LastExistedPrefixDescription = 9;
-    optional fixed64 PathOwnerId = 10;
-    optional ESource Source = 11;
+    string Status = 1;
+    string Reason = 2;
+    string Path = 3;
+    NKikimrSchemeOp.TPathDescription PathDescription = 4;
+    fixed64 DEPRECATED_PathOwner = 5;  // replaced by PathOwnerId
+    fixed64 PathId = 6;
+    string LastExistedPrefixPath = 7;
+    fixed64 LastExistedPrefixPathId = 8;
+    NKikimrSchemeOp.TPathDescription LastExistedPrefixDescription = 9;
+    fixed64 PathOwnerId = 10;
+    ESource Source = 11;
 }
 
 enum EAutocompleteType {
diff --git a/ydb/core/viewer/query_autocomplete_helper.h b/ydb/core/viewer/query_autocomplete_helper.h
index e523ceb029bb..9096a0f4261e 100644
--- a/ydb/core/viewer/query_autocomplete_helper.h
+++ b/ydb/core/viewer/query_autocomplete_helper.h
@@ -1,6 +1,8 @@
 #pragma once
-
+#include <queue>
 #include <util/generic/algorithm.h>
+#include <util/generic/string.h>
+#include <util/generic/vector.h>
 
 namespace NKikimr::NViewer {
 
diff --git a/ydb/core/viewer/scheme_directory.h b/ydb/core/viewer/scheme_directory.h
index 400504fbd822..8198b0a8e597 100644
--- a/ydb/core/viewer/scheme_directory.h
+++ b/ydb/core/viewer/scheme_directory.h
@@ -1,11 +1,10 @@
 #pragma once
-#include <ydb/public/api/grpc/ydb_scheme_v1.grpc.pb.h>
-#include <ydb/core/grpc_services/rpc_calls.h>
-#include "json_local_rpc.h"
 #include "json_handlers.h"
+#include "json_local_rpc.h"
+#include <ydb/core/grpc_services/rpc_calls.h>
+#include <ydb/public/api/grpc/ydb_scheme_v1.grpc.pb.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 class TSchemeDirectory : public IActor {
 public:
@@ -66,6 +65,10 @@ class TSchemeDirectoryRequest : public LocalRpcType {
 
 class TJsonSchemeDirectoryHandler : public TJsonHandler<TSchemeDirectory> {
 public:
+    TJsonSchemeDirectoryHandler()
+        : TJsonHandler<TSchemeDirectory>(GetSwagger())
+    {}
+
     IActor* CreateRequestActor(IViewer* viewer, NMon::TEvHttpInfo::TPtr& event) override {
         switch (event->Get()->Request.GetMethod()) {
             case HTTP_METHOD_GET:
@@ -78,102 +81,100 @@ class TJsonSchemeDirectoryHandler : public TJsonHandler<TSchemeDirectory> {
                 throw std::logic_error("Bad request method");
         }
     }
-};
 
-template<>
-YAML::Node TJsonRequestSwagger<TSchemeDirectory>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
         get:
-          tags:
-          - scheme
-          summary: List directory
-          description: Returns information about given directory and objects inside it
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: path
-            in: query
-            description: path to directory
-            required: true
-            type: string
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
+            tags:
+              - scheme
+            summary: List directory
+            description: Returns information about given directory and objects inside it
+            parameters:
+              - name: database
+                in: query
+                description: database name
+                required: true
+                type: string
+              - name: path
+                in: query
+                description: path to directory
+                required: true
+                type: string
+            responses:
+                200:
+                    description: OK
+                    content:
+                        application/json:
+                            schema: {}
+                400:
+                    description: Bad Request
+                403:
+                    description: Forbidden
+                504:
+                    description: Gateway Timeout
         post:
-          tags:
-          - scheme
-          summary: Make directory
-          description: Makes directory
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: path
-            in: query
-            description: path to directory
-            required: true
-            type: string
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
+            tags:
+              - scheme
+            summary: Make directory
+            description: Makes directory
+            parameters:
+              - name: database
+                in: query
+                description: database name
+                required: true
+                type: string
+              - name: path
+                in: query
+                description: path to directory
+                required: true
+                type: string
+            responses:
+                200:
+                    description: OK
+                    content:
+                        application/json:
+                            schema: {}
+                400:
+                    description: Bad Request
+                403:
+                    description: Forbidden
+                504:
+                    description: Gateway Timeout
         delete:
-          tags:
-          - scheme
-          summary: Remove directory
-          description: Removes directory
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: path
-            in: query
-            description: path to directory
-            required: true
-            type: string
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-
-    node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Scheme::ListDirectoryResult>();
-    node["post"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Scheme::MakeDirectoryResponse>();
-    node["delete"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Scheme::RemoveDirectoryResponse>();
-    return node;
-}
+            tags:
+              - scheme
+            summary: Remove directory
+            description: Removes directory
+            parameters:
+              - name: database
+                in: query
+                description: database name
+                required: true
+                type: string
+              - name: path
+                in: query
+                description: path to directory
+                required: true
+                type: string
+            responses:
+                200:
+                    description: OK
+                    content:
+                        application/json:
+                            schema: {}
+                400:
+                    description: Bad Request
+                403:
+                    description: Forbidden
+                504:
+                    description: Gateway Timeout
+            )___");
+
+        node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Scheme::ListDirectoryResult>();
+        node["post"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Scheme::MakeDirectoryResponse>();
+        node["delete"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Scheme::RemoveDirectoryResponse>();
+        return node;
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/storage_groups.cpp b/ydb/core/viewer/storage_groups.h
similarity index 94%
rename from ydb/core/viewer/storage_groups.cpp
rename to ydb/core/viewer/storage_groups.h
index 8046767b86be..897332a5d176 100644
--- a/ydb/core/viewer/storage_groups.cpp
+++ b/ydb/core/viewer/storage_groups.h
@@ -1,24 +1,12 @@
-#include <unordered_map>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/protos/sys_view.pb.h>
-#include <ydb/core/protos/node_whiteboard.pb.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-#include <library/cpp/json/json_writer.h>
-#include <library/cpp/protobuf/json/proto2json.h>
-#include "viewer.h"
-#include "viewer_helper.h"
+#pragma once
 #include "json_handlers.h"
 #include "json_pipe_req.h"
-#include "json_vdiskinfo.h"
-#include "json_pdiskinfo.h"
-#include "json_bsgroupinfo.h"
+#include "log.h"
+#include "viewer_helper.h"
+#include <library/cpp/protobuf/json/proto2json.h>
+#include <ydb/library/actors/interconnect/interconnect.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NProtobufJson;
 
@@ -74,7 +62,6 @@ struct TVSlotId : TPDiskId {
     bool operator ==(const TVSlotId& a) const = default;
 };
 
-}
 }
 
 template<>
@@ -94,14 +81,11 @@ struct std::hash<NKikimr::NViewer::TVSlotId> {
     }
 };
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
 
-using ::google::protobuf::FieldDescriptor;
-
 enum class EGroupFields : ui8 {
     GroupId,
     PoolName,
@@ -1689,118 +1673,111 @@ class TStorageGroups : public TViewerPipeClient {
         });
         TBase::ReplyAndPassAway(GetHTTPOKJSON(out.Str()));
     }
-};
-
-template <>
-YAML::Node TJsonRequestSwagger<TStorageGroups>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        post:
-          tags:
-          - storage
-          summary: Storage groups
-          description: Information about storage groups
-          parameters:
-              - name: database
-                in: query
-                description: database name
-                required: false
-                type: string
-              - name: pool
-                in: query
-                description: storage pool name
-                required: false
-                type: string
-              - name: node_id
-                in: query
-                description: node id
-                required: false
-                type: integer
-              - name: pdisk_id
-                in: query
-                description: pdisk id
-                required: false
-                type: integer
-              - name: group_id
-                in: query
-                description: group id
-                required: false
-                type: integer
-              - name: need_groups
-                in: query
-                description: return groups information
-                required: false
-                type: boolean
-                default: true
-              - name: need_disks
-                in: query
-                description: return disks information
-                required: false
-                type: boolean
-                default: true
-              - name: with
-                in: query
-                description: >
-                   filter groups by missing or space:
-                    * `missing`
-                    * `space`
-                required: false
-                type: string
-              - name: sort
-                in: query
-                description: >
-                  sort by:
-                   * `PoolName`
-                   * `Kind`
-                   * `MediaType`
-                   * `Erasure`
-                   * `MissingDisks`
-                   * `Usage`
-                   * `GroupId`
-                   * `Used`
-                   * `Limit`
-                   * `Usage`
-                   * `Read`
-                   * `Write`
-                required: false
-                type: string
-              - name: offset
-                in: query
-                description: skip N nodes
-                required: false
-                type: integer
-              - name: limit
-                in: query
-                description: limit to N nodes
-                required: false
-                type: integer
-              - name: timeout
-                in: query
-                description: timeout in ms
-                required: false
-                type: integer
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema:
-                    type: object
-                    description: format depends on schema parameter
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-            )___");
-    node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TStorageGroupsInfo>();
-    return node;
-}
 
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
+            post:
+                tags:
+                  - storage
+                summary: Storage groups
+                description: Information about storage groups
+                parameters:
+                  - name: database
+                    in: query
+                    description: database name
+                    required: false
+                    type: string
+                  - name: pool
+                    in: query
+                    description: storage pool name
+                    required: false
+                    type: string
+                  - name: node_id
+                    in: query
+                    description: node id
+                    required: false
+                    type: integer
+                  - name: pdisk_id
+                    in: query
+                    description: pdisk id
+                    required: false
+                    type: integer
+                  - name: group_id
+                    in: query
+                    description: group id
+                    required: false
+                    type: integer
+                  - name: need_groups
+                    in: query
+                    description: return groups information
+                    required: false
+                    type: boolean
+                    default: true
+                  - name: need_disks
+                    in: query
+                    description: return disks information
+                    required: false
+                    type: boolean
+                    default: true
+                  - name: with
+                    in: query
+                    description: >
+                        filter groups by missing or space:
+                            * `missing`
+                            * `space`
+                    required: false
+                    type: string
+                  - name: sort
+                    in: query
+                    description: >
+                        sort by:
+                            * `PoolName`
+                            * `Kind`
+                            * `MediaType`
+                            * `Erasure`
+                            * `MissingDisks`
+                            * `Usage`
+                            * `GroupId`
+                            * `Used`
+                            * `Limit`
+                            * `Usage`
+                            * `Read`
+                            * `Write`
+                    required: false
+                    type: string
+                  - name: offset
+                    in: query
+                    description: skip N nodes
+                    required: false
+                    type: integer
+                  - name: limit
+                    in: query
+                    description: limit to N nodes
+                    required: false
+                    type: integer
+                  - name: timeout
+                    in: query
+                    description: timeout in ms
+                    required: false
+                    type: integer
+                responses:
+                    200:
+                        description: OK
+                        content:
+                            application/json:
+                                schema:
+                                    type: object
+                                    description: format depends on schema parameter
+                    400:
+                        description: Bad Request
+                    403:
+                        description: Forbidden
+                    504:
+                        description: Gateway Timeout
+                )___");
+        node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TStorageGroupsInfo>();
+        return node;
+    }
+};
 
-void InitStorageGroupsJsonHandler(TJsonHandlers& jsonHandlers) {
-    jsonHandlers.AddHandler("/storage/groups", new TJsonHandler<TStorageGroups>);
 }
-
-} // namespace NViewer
-} // namespace NKikimr
diff --git a/ydb/core/viewer/vdisk_blobindexstat.h b/ydb/core/viewer/vdisk_blobindexstat.h
new file mode 100644
index 000000000000..37e1aa39ea9e
--- /dev/null
+++ b/ydb/core/viewer/vdisk_blobindexstat.h
@@ -0,0 +1,10 @@
+#pragma once
+#include "json_vdisk_req.h"
+#include <ydb/core/blobstorage/vdisk/common/vdisk_events.h>
+
+namespace NKikimr::NViewer {
+
+using TJsonBlobIndexStat = TJsonVDiskRequest<TEvGetLogoBlobIndexStatRequest, TEvGetLogoBlobIndexStatResponse>;
+
+
+}
diff --git a/ydb/core/viewer/json_vdisk_evict.h b/ydb/core/viewer/vdisk_evict.h
similarity index 71%
rename from ydb/core/viewer/json_vdisk_evict.h
rename to ydb/core/viewer/vdisk_evict.h
index c37c5ab5e803..624762654ad1 100644
--- a/ydb/core/viewer/json_vdisk_evict.h
+++ b/ydb/core/viewer/vdisk_evict.h
@@ -1,16 +1,10 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/util/wildcard.h>
-#include <library/cpp/json/json_writer.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
+#include "viewer.h"
+#include <library/cpp/json/json_writer.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -184,82 +178,80 @@ class TJsonVDiskEvict : public TViewerPipeClient {
         TBase::Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json)), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         PassAway();
     }
-};
 
-template <>
-YAML::Node TJsonRequestSwagger<TJsonVDiskEvict>::GetSwagger() {
-    return YAML::Load(R"___(
+    static YAML::Node GetSwagger() {
+        return YAML::Load(R"___(
         post:
-          tags:
-          - vdisk
-          summary: VDisk evict
-          description: VDisk evict
-          parameters:
-          - name: vdisk_id
-            in: query
-            description: vdisk identifier
-            required: false
-            type: string
-          - name: group_id
-            in: query
-            description: group identifier
-            required: false
-            type: integer
-          - name: group_generation_id
-            in: query
-            description: group generation identifier
-            required: false
-            type: integer
-          - name: fail_realm_idx
-            in: query
-            description: fail realm identifier
-            required: false
-            type: integer
-          - name: fail_domain_ids
-            in: query
-            description: fail domain identifier
-            required: false
-            type: integer
-          - name: vdisk_idx
-            in: query
-            description: vdisk idx identifier
-            required: false
-            type: integer
-          - name: timeout
-            in: query
-            description: timeout in ms
-            required: false
-            type: integer
-          - name: force
-            in: query
-            description: attempt forced operation, ignore warnings
-            required: false
-            type: boolean
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema:
-                    type: object
-                    properties:
-                      result:
-                        type: boolean
-                        description: was operation successful or not
-                      error:
-                        type: string
-                        description: details about failed operation
-                      forceRetryPossible:
-                        type: boolean
-                        description: if true, operation can be retried with force flag
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-}
+            tags:
+              - vdisk
+            summary: VDisk evict
+            description: VDisk evict
+            parameters:
+              - name: vdisk_id
+                in: query
+                description: vdisk identifier
+                required: false
+                type: string
+              - name: group_id
+                in: query
+                description: group identifier
+                required: false
+                type: integer
+              - name: group_generation_id
+                in: query
+                description: group generation identifier
+                required: false
+                type: integer
+              - name: fail_realm_idx
+                in: query
+                description: fail realm identifier
+                required: false
+                type: integer
+              - name: fail_domain_ids
+                in: query
+                description: fail domain identifier
+                required: false
+                type: integer
+              - name: vdisk_idx
+                in: query
+                description: vdisk idx identifier
+                required: false
+                type: integer
+              - name: timeout
+                in: query
+                description: timeout in ms
+                required: false
+                type: integer
+              - name: force
+                in: query
+                description: attempt forced operation, ignore warnings
+                required: false
+                type: boolean
+            responses:
+                200:
+                    description: OK
+                    content:
+                        application/json:
+                            schema:
+                                type: object
+                                properties:
+                                    result:
+                                        type: boolean
+                                        description: was operation successful or not
+                                    error:
+                                        type: string
+                                        description: details about failed operation
+                                    forceRetryPossible:
+                                        type: boolean
+                                        description: if true, operation can be retried with force flag
+                400:
+                    description: Bad Request
+                403:
+                    description: Forbidden
+                504:
+                    description: Gateway Timeout
+            )___");
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/json_getblob.h b/ydb/core/viewer/vdisk_getblob.h
similarity index 80%
rename from ydb/core/viewer/json_getblob.h
rename to ydb/core/viewer/vdisk_getblob.h
index d09c691dcb90..71340249b78e 100644
--- a/ydb/core/viewer/json_getblob.h
+++ b/ydb/core/viewer/vdisk_getblob.h
@@ -1,14 +1,9 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/util/tuples.h>
+#include "json_handlers.h"
 #include "json_vdisk_req.h"
+#include <ydb/core/blobstorage/vdisk/common/vdisk_events.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using TJsonGetBlob = TJsonVDiskRequest<TEvGetLogoBlobRequest, TEvGetLogoBlobResponse>;
 
@@ -79,20 +74,4 @@ struct TJsonVDiskRequestHelper<TEvGetLogoBlobRequest, TEvGetLogoBlobResponse>  {
     }
 };
 
-
-template <>
-struct TJsonRequestSummary<TJsonGetBlob> {
-    static TString GetSummary() {
-        return "Get blob from VDisk";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonGetBlob> {
-    static TString GetDescription() {
-        return "Get blob from VDisk";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/vdisk_vdiskstat.h b/ydb/core/viewer/vdisk_vdiskstat.h
new file mode 100644
index 000000000000..8d71da596369
--- /dev/null
+++ b/ydb/core/viewer/vdisk_vdiskstat.h
@@ -0,0 +1,9 @@
+#pragma once
+#include "json_vdisk_req.h"
+#include <ydb/core/blobstorage/vdisk/common/vdisk_events.h>
+
+namespace NKikimr::NViewer {
+
+using TJsonVDiskStat = TJsonVDiskRequest<TEvVDiskStatRequest, TEvVDiskStatResponse>;
+
+}
diff --git a/ydb/core/viewer/viewer.cpp b/ydb/core/viewer/viewer.cpp
index ea22224d02ab..fb8a9f5c2734 100644
--- a/ydb/core/viewer/viewer.cpp
+++ b/ydb/core/viewer/viewer.cpp
@@ -1,83 +1,40 @@
-#include <ydb/core/blobstorage/base/blobstorage_events.h>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/core/mon/mon.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/appdata.h>
+#include "viewer.h"
+#include "counters_hosts.h"
+#include "json_handlers.h"
+#include "log.h"
+#include "viewer_request.h"
+#include <library/cpp/mime/types/mime.h>
 #include <library/cpp/monlib/service/pages/templates.h>
-#include <ydb/library/actors/core/interconnect.h>
+#include <library/cpp/protobuf/json/proto2json.h>
 #include <util/generic/algorithm.h>
+#include <util/stream/file.h>
+#include <util/system/fstat.h>
+#include <ydb/core/base/appdata.h>
 #include <ydb/core/base/path.h>
+#include <ydb/core/base/statestorage.h>
 #include <ydb/core/base/tablet_types.h>
+#include <ydb/core/mon/mon.h>
 #include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/base/statestorage.h>
-#include <library/cpp/mime/types/mime.h>
-#include <library/cpp/lwtrace/all.h>
-#include <library/cpp/lwtrace/mon/mon_lwtrace.h>
-#include <contrib/libs/yaml-cpp/include/yaml-cpp/yaml.h>
-#include <library/cpp/yaml/as/tstring.h>
-#include <library/cpp/protobuf/json/proto2json.h>
-#include <util/system/fstat.h>
-#include <util/stream/file.h>
-#include "viewer.h"
-#include "viewer_request.h"
-#include "viewer_probes.h"
-#include <ydb/core/viewer/json/json.h>
 #include <ydb/core/util/wildcard.h>
-#include "browse_pq.h"
-#include "browse_db.h"
-#include "counters_hosts.h"
-#include "json_healthcheck.h"
-
-#include "json_handlers.h"
-
-#include "json_bsgroupinfo.h"
-#include "json_nodeinfo.h"
-#include "json_vdiskinfo.h"
-
+#include <ydb/library/aclib/aclib.h>
+#include <ydb/library/actors/core/actor_bootstrapped.h>
+#include <util/system/hostname.h>
+#include <ydb/library/actors/core/mon.h>
+#include <ydb/library/yql/public/issue/yql_issue_message.h>
+#include <ydb/public/api/protos/ydb_monitoring.pb.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NNodeWhiteboard;
 
 extern void InitViewerJsonHandlers(TJsonHandlers& jsonHandlers);
+extern void InitViewerBrowseJsonHandlers(TJsonHandlers& jsonHandlers);
 extern void InitPDiskJsonHandlers(TJsonHandlers& jsonHandlers);
 extern void InitVDiskJsonHandlers(TJsonHandlers& jsonHandlers);
 extern void InitOperationJsonHandlers(TJsonHandlers& jsonHandlers);
 extern void InitSchemeJsonHandlers(TJsonHandlers& jsonHandlers);
 extern void InitStorageJsonHandlers(TJsonHandlers& jsonHandlers);
 
-void SetupPQVirtualHandlers(IViewer* viewer) {
-    viewer->RegisterVirtualHandler(
-        NKikimrViewer::EObjectType::Root,
-        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
-            return new NViewerPQ::TBrowseRoot(owner, browseContext);
-        });
-    viewer->RegisterVirtualHandler(
-        NKikimrViewer::EObjectType::Consumers,
-        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
-            return new NViewerPQ::TBrowseConsumers(owner, browseContext);
-        });
-    viewer->RegisterVirtualHandler(
-        NKikimrViewer::EObjectType::Consumer,
-        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
-            return new NViewerPQ::TBrowseConsumer(owner, browseContext);
-        });
-    viewer->RegisterVirtualHandler(
-        NKikimrViewer::EObjectType::Topic,
-        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
-            return new NViewerPQ::TBrowseTopic(owner, browseContext);
-        });
-}
-
-void SetupDBVirtualHandlers(IViewer* viewer) {
-    viewer->RegisterVirtualHandler(
-        NKikimrViewer::EObjectType::Table,
-        [] (const TActorId& owner, const IViewer::TBrowseContext& browseContext) -> IActor* {
-            return new NViewerDB::TBrowseTable(owner, browseContext);
-        });
-}
-
 class TViewer : public TActorBootstrapped<TViewer>, public IViewer {
 public:
     static constexpr NKikimrServices::TActivity::EType ActorActivityType() {
@@ -95,7 +52,6 @@ class TViewer : public TActorBootstrapped<TViewer>, public IViewer {
         Become(&TThis::StateWork);
         NActors::TMon* mon = AppData(ctx)->Mon;
         if (mon) {
-            NLwTraceMonPage::ProbeRegistry().AddProbesList(LWTRACE_GET_PROBES(VIEWER_PROVIDER));
             TVector<TString> viewerAllowedSIDs;
             TVector<TString> monitoringAllowedSIDs;
             {
@@ -189,6 +145,7 @@ class TViewer : public TActorBootstrapped<TViewer>, public IViewer {
             InitStorageJsonHandlers(JsonHandlers);
             InitOperationJsonHandlers(JsonHandlers);
             InitSchemeJsonHandlers(JsonHandlers);
+            InitViewerBrowseJsonHandlers(JsonHandlers);
 
             for (const auto& handler : JsonHandlers.JsonHandlersList) {
                 // temporary handling of old paths
@@ -206,9 +163,6 @@ class TViewer : public TActorBootstrapped<TViewer>, public IViewer {
             JsonHandlers.JsonHandlersIndex["/viewer/v2/json/nodelist"] = JsonHandlers.JsonHandlersIndex["/viewer/nodelist"];
             JsonHandlers.JsonHandlersIndex["/viewer/v2/json/tabletinfo"] = JsonHandlers.JsonHandlersIndex["/viewer/tabletinfo"];
             JsonHandlers.JsonHandlersIndex["/viewer/v2/json/nodeinfo"] = JsonHandlers.JsonHandlersIndex["/viewer/nodeinfo"];
-
-            TWhiteboardInfo<NKikimrWhiteboard::TEvNodeStateResponse>::InitMerger();
-            TWhiteboardInfo<NKikimrWhiteboard::TEvBSGroupStateResponse>::InitMerger();
         }
     }
 
@@ -414,24 +368,9 @@ class TViewer : public TActorBootstrapped<TViewer>, public IViewer {
         YAML::Node paths;
         for (const TString& name : JsonHandlers.JsonHandlersList) {
             const auto& handler = JsonHandlers.JsonHandlersIndex[name];
-            TString tag = TString(TStringBuf(name.substr(1)).Before('/'));
-            auto path = paths[name];
             auto swagger = handler->GetRequestSwagger();
-            if (swagger.IsNull()) {
-                auto get = path["get"];
-                get["tags"].push_back(tag);
-                if (auto summary = handler->GetRequestSummary()) {
-                    get["summary"] = summary;
-                }
-                if (auto description = handler->GetRequestDescription()) {
-                    get["description"] = description;
-                }
-                get["parameters"] = handler->GetRequestParameters();
-                auto responses = get["responses"];
-                auto response200 = responses["200"];
-                response200["content"]["application/json"]["schema"] = handler->GetResponseJsonSchema();
-            } else {
-                path = swagger;
+            if (!swagger.IsNull()) {
+                paths[name] = swagger;
             }
         }
         return paths;
@@ -987,100 +926,6 @@ NKikimrViewer::EFlag GetVDiskOverallFlag(const NKikimrWhiteboard::TVDiskStateInf
     return flag;
 }
 
-TBSGroupState GetBSGroupOverallStateWithoutLatency(
-        const NKikimrWhiteboard::TBSGroupStateInfo& info,
-        const TMap<NKikimrBlobStorage::TVDiskID, const NKikimrWhiteboard::TVDiskStateInfo&>& vDisksIndex,
-        const TMap<std::pair<ui32, ui32>, const NKikimrWhiteboard::TPDiskStateInfo&>& pDisksIndex) {
-
-    TBSGroupState groupState;
-    groupState.Overall = NKikimrViewer::EFlag::Grey;
-
-    const auto& vDiskIds = info.GetVDiskIds();
-    std::unordered_map<ui32, ui32> failedRings;
-    std::unordered_map<ui32, ui32> failedDomains;
-    TVector<NKikimrViewer::EFlag> vDiskFlags;
-    vDiskFlags.reserve(vDiskIds.size());
-    for (auto iv = vDiskIds.begin(); iv != vDiskIds.end(); ++iv) {
-        const NKikimrBlobStorage::TVDiskID& vDiskId = *iv;
-        NKikimrViewer::EFlag flag = NKikimrViewer::EFlag::Grey;
-        auto ie = vDisksIndex.find(vDiskId);
-        if (ie != vDisksIndex.end()) {
-            auto pDiskId = std::make_pair(ie->second.GetNodeId(), ie->second.GetPDiskId());
-            auto ip = pDisksIndex.find(pDiskId);
-            if (ip != pDisksIndex.end()) {
-                const NKikimrWhiteboard::TPDiskStateInfo& pDiskInfo(ip->second);
-                flag = Max(flag, GetPDiskOverallFlag(pDiskInfo));
-            } else {
-                flag = NKikimrViewer::EFlag::Red;
-            }
-            const NKikimrWhiteboard::TVDiskStateInfo& vDiskInfo(ie->second);
-            flag = Max(flag, GetVDiskOverallFlag(vDiskInfo));
-            if (vDiskInfo.GetDiskSpace() > NKikimrWhiteboard::EFlag::Green) {
-                groupState.SpaceProblems++;
-            }
-        } else {
-            flag = NKikimrViewer::EFlag::Red;
-        }
-        vDiskFlags.push_back(flag);
-        if (flag == NKikimrViewer::EFlag::Red || flag == NKikimrViewer::EFlag::Blue) {
-            groupState.MissingDisks++;
-            ++failedRings[vDiskId.GetRing()];
-            ++failedDomains[vDiskId.GetDomain()];
-        }
-        groupState.Overall = Max(groupState.Overall, flag);
-    }
-
-    groupState.Overall = Min(groupState.Overall, NKikimrViewer::EFlag::Yellow); // without failed rings we only allow to raise group status up to Blue/Yellow
-    TString erasure = info.GetErasureSpecies();
-    if (erasure == TErasureType::ErasureSpeciesName(TErasureType::ErasureNone)) {
-        if (!failedDomains.empty()) {
-            groupState.Overall = NKikimrViewer::EFlag::Red;
-        }
-    } else if (erasure == TErasureType::ErasureSpeciesName(TErasureType::ErasureMirror3dc)) {
-        if (failedRings.size() > 2) {
-            groupState.Overall = NKikimrViewer::EFlag::Red;
-        } else if (failedRings.size() == 2) { // TODO: check for 1 ring - 1 domain rule
-            groupState.Overall = NKikimrViewer::EFlag::Orange;
-        } else if (failedRings.size() > 0) {
-            groupState.Overall = Min(groupState.Overall, NKikimrViewer::EFlag::Yellow);
-        }
-    } else if (erasure == TErasureType::ErasureSpeciesName(TErasureType::Erasure4Plus2Block)) {
-        if (failedDomains.size() > 2) {
-            groupState.Overall = NKikimrViewer::EFlag::Red;
-        } else if (failedDomains.size() > 1) {
-            groupState.Overall = NKikimrViewer::EFlag::Orange;
-        } else if (failedDomains.size() > 0) {
-            groupState.Overall = Min(groupState.Overall, NKikimrViewer::EFlag::Yellow);
-        }
-    }
-    return groupState;
-}
-
-NKikimrViewer::EFlag GetBSGroupOverallFlagWithoutLatency(
-        const NKikimrWhiteboard::TBSGroupStateInfo& info,
-        const TMap<NKikimrBlobStorage::TVDiskID, const NKikimrWhiteboard::TVDiskStateInfo&>& vDisksIndex,
-        const TMap<std::pair<ui32, ui32>, const NKikimrWhiteboard::TPDiskStateInfo&>& pDisksIndex) {
-    return GetBSGroupOverallStateWithoutLatency(info, vDisksIndex, pDisksIndex).Overall;
-}
-
-TBSGroupState GetBSGroupOverallState(
-        const NKikimrWhiteboard::TBSGroupStateInfo& info,
-        const TMap<NKikimrBlobStorage::TVDiskID, const NKikimrWhiteboard::TVDiskStateInfo&>& vDisksIndex,
-        const TMap<std::pair<ui32, ui32>, const NKikimrWhiteboard::TPDiskStateInfo&>& pDisksIndex) {
-    TBSGroupState state = GetBSGroupOverallStateWithoutLatency(info, vDisksIndex, pDisksIndex);
-    if (info.HasLatency()) {
-        state.Overall = Max(state.Overall, Min(NKikimrViewer::EFlag::Yellow, GetViewerFlag(info.GetLatency())));
-    }
-    return state;
-}
-
-NKikimrViewer::EFlag GetBSGroupOverallFlag(
-        const NKikimrWhiteboard::TBSGroupStateInfo& info,
-        const TMap<NKikimrBlobStorage::TVDiskID, const NKikimrWhiteboard::TVDiskStateInfo&>& vDisksIndex,
-        const TMap<std::pair<ui32, ui32>, const NKikimrWhiteboard::TPDiskStateInfo&>& pDisksIndex) {
-    return GetBSGroupOverallState(info, vDisksIndex, pDisksIndex).Overall;
-}
-
 NKikimrViewer::EFlag GetViewerFlag(Ydb::Monitoring::StatusFlag::Status flag) {
     switch (flag) {
     case Ydb::Monitoring::StatusFlag::GREY:
@@ -1136,5 +981,4 @@ NKikimrViewer::EFlag GetViewerFlag(NKikimrWhiteboard::EFlag flag) {
     return static_cast<NKikimrViewer::EFlag>((int)flag);
 }
 
-} // NNodeTabletMonitor
-} // NKikimr
+}
diff --git a/ydb/core/viewer/viewer.h b/ydb/core/viewer/viewer.h
index 67cac550005c..b41bd789c1a5 100644
--- a/ydb/core/viewer/viewer.h
+++ b/ydb/core/viewer/viewer.h
@@ -1,21 +1,14 @@
 #pragma once
-
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/viewer/yaml/yaml.h>
-
+#include <ydb/core/driver_lib/run/config.h>
 #include <ydb/core/tablet/defs.h>
-#include <ydb/library/actors/core/defs.h>
+#include <ydb/core/viewer/json/json.h>
+#include <ydb/core/viewer/protos/viewer.pb.h>
 #include <ydb/library/actors/core/actor.h>
+#include <ydb/library/actors/core/defs.h>
 #include <ydb/library/actors/core/event.h>
-#include <ydb/library/actors/wilson/wilson_span.h>
-#include <ydb/core/driver_lib/run/config.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-#include <ydb/public/api/protos/ydb_monitoring.pb.h>
 #include <ydb/public/sdk/cpp/client/ydb_types/status/status.h>
-#include <util/system/hostname.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 inline TActorId MakeViewerID(ui32 node) {
     char x[12] = {'v','i','e','w','e','r'};
@@ -214,32 +207,6 @@ void SetupPQVirtualHandlers(IViewer* viewer);
 void SetupDBVirtualHandlers(IViewer* viewer);
 void SetupKqpContentHandler(IViewer* viewer);
 
-template <typename RequestType>
-struct TJsonRequestSchema {
-    static YAML::Node GetSchema() { return {}; }
-};
-
-template <typename RequestType>
-struct TJsonRequestSummary {
-    static TString GetSummary() { return {}; }
-};
-
-template <typename RequestType>
-struct TJsonRequestDescription {
-    static TString GetDescription() { return {}; }
-};
-
-template <typename RequestType>
-struct TJsonRequestParameters {
-    static YAML::Node GetParameters() { return {}; }
-};
-
-template <typename RequestType>
-struct TJsonRequestSwagger {
-    static YAML::Node GetSwagger() { return {}; }
-};
-
-
 template <typename ValueType, typename OutputIteratorType>
 void GenericSplitIds(TStringBuf source, char delim, OutputIteratorType it) {
     for (TStringBuf value = source.NextTok(delim); !value.empty(); value = source.NextTok(delim)) {
@@ -300,8 +267,5 @@ NKikimrViewer::EFlag GetFlagFromUsage(double usage);
 
 NKikimrWhiteboard::EFlag GetWhiteboardFlag(NKikimrViewer::EFlag flag);
 NKikimrViewer::EFlag GetViewerFlag(NKikimrWhiteboard::EFlag flag);
-NKikimrViewer::EFlag GetViewerFlag(Ydb::Monitoring::StatusFlag::Status flag);
 
-
-} // NViewer
-} // NKikimr
+}
diff --git a/ydb/core/viewer/json_acl.h b/ydb/core/viewer/viewer_acl.h
similarity index 56%
rename from ydb/core/viewer/json_acl.h
rename to ydb/core/viewer/viewer_acl.h
index 14055628e0db..2a2147b507f5 100644
--- a/ydb/core/viewer/json_acl.h
+++ b/ydb/core/viewer/viewer_acl.h
@@ -1,33 +1,24 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
+#include "log.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
-using NSchemeShard::TEvSchemeShard;
 
 class TJsonACL : public TViewerPipeClient {
     using TThis = TJsonACL;
     using TBase = TViewerPipeClient;
-    IViewer* Viewer;
-    NMon::TEvHttpInfo::TPtr Event;
+    using TBase::ReplyAndPassAway;
     TAutoPtr<TEvTxProxySchemeCache::TEvNavigateKeySetResult> CacheResult;
     TJsonSettings JsonSettings;
     bool MergeRules = false;
     ui32 Timeout = 0;
 
 public:
-    TJsonACL(IViewer* viewer, NMon::TEvHttpInfo::TPtr &ev)
-        : Viewer(viewer)
-        , Event(ev)
+    TJsonACL(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TViewerPipeClient(viewer, ev)
     {}
 
     void Bootstrap() override {
@@ -150,23 +141,18 @@ class TJsonACL : public TViewerPipeClient {
         }
     }
 
-    void ReplyAndPassAway(TString data) {
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(data, 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
-    }
-
     void ReplyAndPassAway() override {
         if (CacheResult == nullptr) {
-            return ReplyAndPassAway(Viewer->GetHTTPINTERNALERROR(Event->Get(), "text/plain", "no SchemeCache response"));
+            return ReplyAndPassAway(GetHTTPINTERNALERROR("text/plain", "no SchemeCache response"));
         }
         if (CacheResult->Request == nullptr) {
-            return ReplyAndPassAway(Viewer->GetHTTPINTERNALERROR(Event->Get(), "text/plain", "wrong SchemeCache response"));
+            return ReplyAndPassAway(GetHTTPINTERNALERROR("text/plain", "wrong SchemeCache response"));
         }
         if (CacheResult->Request.Get()->ResultSet.empty()) {
-            return ReplyAndPassAway(Viewer->GetHTTPINTERNALERROR(Event->Get(), "text/plain", "SchemeCache response is empty"));
+            return ReplyAndPassAway(GetHTTPINTERNALERROR("text/plain", "SchemeCache response is empty"));
         }
         if (CacheResult->Request.Get()->ErrorCount != 0) {
-            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", TStringBuilder() << "SchemeCache response error " << static_cast<int>(CacheResult->Request.Get()->ResultSet.front().Status)));
+            return ReplyAndPassAway(GetHTTPBADREQUEST("text/plain", TStringBuilder() << "SchemeCache response error " << static_cast<int>(CacheResult->Request.Get()->ResultSet.front().Status)));
         }
         const auto& entry = CacheResult->Request.Get()->ResultSet.front();
         NKikimrViewer::TMetaInfo metaInfo;
@@ -191,110 +177,103 @@ class TJsonACL : public TViewerPipeClient {
         TStringStream json;
         TProtoToJson::ProtoToJson(json, metaInfo, JsonSettings);
 
-        ReplyAndPassAway(Viewer->GetHTTPOKJSON(Event->Get(), json.Str()));
+        ReplyAndPassAway(GetHTTPOKJSON(json.Str()));
     }
 
-    void HandleTimeout() {
-        ReplyAndPassAway(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()));
-    }
-};
-
-template <>
-YAML::Node TJsonRequestSwagger<TJsonACL>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
         get:
-          tags:
-          - viewer
-          summary: ACL information
-          description: Returns information about ACL of an object
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            type: string
-            required: false
-          - name: path
-            in: query
-            description: schema path
-            required: true
-            type: string
-          - name: merge_rules
-            in: query
-            description: merge access rights into access rules
-            type: boolean
-          - name: timeout
-            in: query
-            description: timeout in ms
-            required: false
-            type: integer
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema:
-                    type: object
-                    properties:
-                      Common:
-                        type: object
-                        properties:
-                          Path:
-                            type: string
-                          Owner:
-                            type: string
-                          ACL:
-                            type: array
-                            items:
-                              type: object
-                              properties:
-                                AccessType:
-                                  type: string
-                                Subject:
-                                  type: string
-                                AccessRules:
-                                  type: array
-                                  items:
-                                    type: string
-                                AccessRights:
-                                  type: array
-                                  items:
-                                    type: string
-                                InheritanceType:
-                                  type: array
-                                  items:
-                                    type: string
-                          EffectiveACL:
-                            type: array
-                            items:
-                              type: object
-                              properties:
-                                AccessType:
-                                  type: string
-                                Subject:
-                                  type: string
-                                AccessRules:
-                                  type: array
-                                  items:
-                                    type: string
-                                AccessRights:
-                                  type: array
-                                  items:
-                                    type: string
-                                InheritanceType:
-                                  type: array
-                                  items:
-                                    type: string
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
+            tags:
+              - viewer
+            summary: ACL information
+            description: Returns information about ACL of an object
+            parameters:
+              - name: database
+                in: query
+                description: database name
+                type: string
+                required: false
+              - name: path
+                in: query
+                description: schema path
+                required: true
+                type: string
+              - name: merge_rules
+                in: query
+                description: merge access rights into access rules
+                type: boolean
+              - name: timeout
+                in: query
+                description: timeout in ms
+                required: false
+                type: integer
+            responses:
+                200:
+                    description: OK
+                    content:
+                        application/json:
+                            schema:
+                                type: object
+                                properties:
+                                    Common:
+                                        type: object
+                                        properties:
+                                            Path:
+                                                type: string
+                                            Owner:
+                                                type: string
+                                            ACL:
+                                                type: array
+                                                items:
+                                                    type: object
+                                                    properties:
+                                                        AccessType:
+                                                            type: string
+                                                        Subject:
+                                                            type: string
+                                                        AccessRules:
+                                                            type: array
+                                                            items:
+                                                                type: string
+                                                        AccessRights:
+                                                            type: array
+                                                            items:
+                                                                type: string
+                                                        InheritanceType:
+                                                            type: array
+                                                            items:
+                                                                type: string
+                                            EffectiveACL:
+                                                type: array
+                                                items:
+                                                    type: object
+                                                properties:
+                                                    AccessType:
+                                                        type: string
+                                                    Subject:
+                                                        type: string
+                                                    AccessRules:
+                                                        type: array
+                                                        items:
+                                                            type: string
+                                                    AccessRights:
+                                                        type: array
+                                                        items:
+                                                            type: string
+                                                    InheritanceType:
+                                                        type: array
+                                                        items:
+                                                            type: string
+                400:
+                    description: Bad Request
+                403:
+                    description: Forbidden
+                504:
+                    description: Gateway Timeout
+                )___");
 
-            )___");
-
-    return node;
-}
+        return node;
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/json_autocomplete.h b/ydb/core/viewer/viewer_autocomplete.h
similarity index 88%
rename from ydb/core/viewer/json_autocomplete.h
rename to ydb/core/viewer/viewer_autocomplete.h
index d9733e4550a1..396e5d98b111 100644
--- a/ydb/core/viewer/json_autocomplete.h
+++ b/ydb/core/viewer/viewer_autocomplete.h
@@ -1,16 +1,11 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/viewer/json/json.h>
-
+#include "json_handlers.h"
+#include "json_pipe_req.h"
+#include "log.h"
 #include "query_autocomplete_helper.h"
 #include "viewer_request.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using TNavigate = NSchemeCache::TSchemeCacheNavigate;
@@ -439,78 +434,58 @@ class TJsonAutocomplete : public TViewerPipeClient {
             Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
             PassAway();
         }
-
     }
-};
 
-template <>
-struct TJsonRequestSchema<TJsonAutocomplete> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TQueryAutocomplete>();
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Autocomplete information",
+            .Description = "Returns autocomplete information about objects in the database"
+        });
+        yaml.AddParameter({
+            .Name = "database",
+            .Description = "database name",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "table",
+            .Description = "table list",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "prefix",
+            .Description = "known part of the word",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "limit",
+            .Description = "limit of entities",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "direct",
+            .Description = "force execution on current node",
+            .Type = "boolean",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TQueryAutocomplete>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestParameters<TJsonAutocomplete> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: database
-              in: query
-              description: database name
-              required: false
-              type: string
-            - name: table
-              in: query
-              description: table list
-              required: false
-              type: string
-            - name: prefix
-              in: query
-              description: known part of the word
-              required: false
-              type: string
-            - name: limit
-              in: query
-              description: limit of entities
-              required: false
-              type: integer
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: direct
-              in: query
-              description: force execution on current node
-              required: false
-              type: boolean
-            )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonAutocomplete> {
-    static TString GetSummary() {
-        return "Autocomplete information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonAutocomplete> {
-    static TString GetDescription() {
-        return "Returns autocomplete information about objects in the database";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_browse.h b/ydb/core/viewer/viewer_browse.h
similarity index 80%
rename from ydb/core/viewer/json_browse.h
rename to ydb/core/viewer/viewer_browse.h
index 223e91571b6a..82bc218c97e6 100644
--- a/ydb/core/viewer/json_browse.h
+++ b/ydb/core/viewer/viewer_browse.h
@@ -1,21 +1,10 @@
-#pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
 #include "browse.h"
 #include "browse_db.h"
-#include "browse_pq.h"
-#include <ydb/core/viewer/json/json.h>
+#include "json_handlers.h"
 #include "viewer.h"
 #include "wb_aggregate.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -199,56 +188,37 @@ class TJsonBrowse : public TActorBootstrapped<TJsonBrowse> {
             html << request << Endl;
         }
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonBrowse> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TBrowseInfo>();
-    }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonBrowse> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: path
-              in: query
-              description: schema path
-              required: true
-              type: string
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-        )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonBrowse> {
-    static TString GetSummary() {
-        return "Schema information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonBrowse> {
-    static TString GetDescription() {
-        return "Returns brief information about schema object";
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "obsolete",
+            .Summary = "Schema information",
+            .Description = "Returns brief information about schema object"
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+            .Required = true
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean"
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean"
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer"
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TBrowseInfo>());
+        return yaml;
     }
 };
 
 }
-}
diff --git a/ydb/core/viewer/viewer_bscontrollerinfo.h b/ydb/core/viewer/viewer_bscontrollerinfo.h
new file mode 100644
index 000000000000..95b7c51be01a
--- /dev/null
+++ b/ydb/core/viewer/viewer_bscontrollerinfo.h
@@ -0,0 +1,88 @@
+#pragma once
+#include "json_handlers.h"
+#include "json_pipe_req.h"
+#include "viewer.h"
+
+namespace NKikimr::NViewer {
+
+using namespace NActors;
+
+class TJsonBSControllerInfo : public TViewerPipeClient {
+    using TThis = TJsonBSControllerInfo;
+    using TBase = TViewerPipeClient;
+    using TBase::ReplyAndPassAway;
+    TAutoPtr<TEvBlobStorage::TEvResponseControllerInfo> ControllerInfo;
+    TJsonSettings JsonSettings;
+    ui32 Timeout = 0;
+
+public:
+    TJsonBSControllerInfo(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TViewerPipeClient(viewer, ev)
+    {}
+
+    void Bootstrap() override {
+        const auto& params(Event->Get()->Request.GetParams());
+        JsonSettings.EnumAsNumbers = !FromStringWithDefault<bool>(params.Get("enums"), false);
+        JsonSettings.UI64AsString = !FromStringWithDefault<bool>(params.Get("ui64"), false);
+        Timeout = FromStringWithDefault<ui32>(params.Get("timeout"), 10000);
+        InitConfig(params);
+        RequestBSControllerInfo();
+        Become(&TThis::StateRequestedInfo, TDuration::MilliSeconds(Timeout), new TEvents::TEvWakeup());
+    }
+
+    STATEFN(StateRequestedInfo) {
+        switch (ev->GetTypeRewrite()) {
+            hFunc(TEvBlobStorage::TEvResponseControllerInfo, Handle);
+            hFunc(TEvTabletPipe::TEvClientConnected, TBase::Handle);
+            cFunc(TEvents::TSystem::Wakeup, TBase::HandleTimeout);
+        }
+    }
+
+    void Handle(TEvBlobStorage::TEvResponseControllerInfo::TPtr& ev) {
+        ControllerInfo = ev->Release();
+        RequestDone();
+    }
+
+    void ReplyAndPassAway() override {
+        TStringStream json;
+        if (ControllerInfo != nullptr) {
+            TProtoToJson::ProtoToJson(json, ControllerInfo->Record);
+        } else {
+            json << "null";
+        }
+        ReplyAndPassAway(GetHTTPOKJSON(json.Str()));
+    }
+
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Storage controller information",
+            .Description = "Returns information about storage controller"
+        });
+        yaml.AddParameter({
+            .Name = "controller_id",
+            .Description = "storage controller identifier (tablet id)",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TEvBlobStorage::TEvResponseControllerInfo::ProtoRecordType>());
+        return yaml;
+    }
+};
+
+}
diff --git a/ydb/core/viewer/json_bsgroupinfo.h b/ydb/core/viewer/viewer_bsgroupinfo.h
similarity index 75%
rename from ydb/core/viewer/json_bsgroupinfo.h
rename to ydb/core/viewer/viewer_bsgroupinfo.h
index 24c05ffe5d7a..ba8f6a63835c 100644
--- a/ydb/core/viewer/json_bsgroupinfo.h
+++ b/ydb/core/viewer/viewer_bsgroupinfo.h
@@ -1,14 +1,7 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include "wb_merge.h"
 #include "json_wb_req.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 template <>
 struct TWhiteboardInfo<NKikimrWhiteboard::TEvBSGroupStateResponse> {
@@ -55,19 +48,4 @@ struct TWhiteboardMergerComparator<NKikimrWhiteboard::TBSGroupStateInfo> {
 
 using TJsonBSGroupInfo = TJsonWhiteboardRequest<TEvWhiteboard::TEvBSGroupStateRequest, TEvWhiteboard::TEvBSGroupStateResponse>;
 
-template <>
-struct TJsonRequestSummary<TJsonBSGroupInfo> {
-    static TString GetSummary() {
-        return "Storage groups information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonBSGroupInfo> {
-    static TString GetDescription() {
-        return "Returns information about storage groups";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/viewer_capabilities.cpp b/ydb/core/viewer/viewer_capabilities.cpp
deleted file mode 100644
index ee96e078bb96..000000000000
--- a/ydb/core/viewer/viewer_capabilities.cpp
+++ /dev/null
@@ -1,65 +0,0 @@
-#include <unordered_map>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <library/cpp/json/json_writer.h>
-#include "viewer.h"
-#include "json_handlers.h"
-#include "json_pipe_req.h"
-
-namespace NKikimr {
-namespace NViewer {
-
-using namespace NActors;
-
-class TViewerCapabilities : public TViewerPipeClient {
-public:
-    using TThis = TViewerCapabilities;
-    using TBase = TViewerPipeClient;
-
-    TViewerCapabilities(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
-        : TBase(viewer, ev)
-    {}
-
-    void Bootstrap() override {
-        ReplyAndPassAway();
-    }
-
-    void ReplyAndPassAway() override {
-        NJson::TJsonValue json;
-        json["Capabilities"] = Viewer->GetCapabilities();
-        TBase::ReplyAndPassAway(GetHTTPOKJSON(NJson::WriteJson(json, false)));
-    }
-};
-
-template <>
-YAML::Node TJsonRequestSwagger<TViewerCapabilities>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        post:
-          tags:
-          - viewer
-          summary: Viewer capabilities
-          description: Viewer capabilities
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema:
-                    type: object
-                    description: format depends on schema parameter
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-            )___");
-    return node;
-}
-
-
-void InitViewerCapabilitiesJsonHandler(TJsonHandlers& jsonHandlers) {
-    jsonHandlers.AddHandler("/viewer/capabilities", new TJsonHandler<TViewerCapabilities>());
-}
-
-} // namespace NViewer
-} // namespace NKikimr
diff --git a/ydb/core/viewer/viewer_capabilities.h b/ydb/core/viewer/viewer_capabilities.h
new file mode 100644
index 000000000000..3804ecbede94
--- /dev/null
+++ b/ydb/core/viewer/viewer_capabilities.h
@@ -0,0 +1,28 @@
+#pragma once
+#include "json_pipe_req.h"
+
+namespace NKikimr::NViewer {
+
+using namespace NActors;
+
+class TViewerCapabilities : public TViewerPipeClient {
+public:
+    using TThis = TViewerCapabilities;
+    using TBase = TViewerPipeClient;
+
+    TViewerCapabilities(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TBase(viewer, ev)
+    {}
+
+    void Bootstrap() override {
+        ReplyAndPassAway();
+    }
+
+    void ReplyAndPassAway() override {
+        NJson::TJsonValue json;
+        json["Capabilities"] = Viewer->GetCapabilities();
+        TBase::ReplyAndPassAway(GetHTTPOKJSON(json));
+    }
+};
+
+}
diff --git a/ydb/core/viewer/viewer_check_access.h b/ydb/core/viewer/viewer_check_access.h
new file mode 100644
index 000000000000..55c088413111
--- /dev/null
+++ b/ydb/core/viewer/viewer_check_access.h
@@ -0,0 +1,208 @@
+#pragma once
+#include "json_handlers.h"
+#include "json_pipe_req.h"
+#include "log.h"
+#include <ydb/core/ydb_convert/ydb_convert.h>
+
+namespace NKikimr::NViewer {
+
+using namespace NActors;
+using TNavigate = NSchemeCache::TSchemeCacheNavigate;
+
+class TCheckAccess : public TViewerPipeClient {
+    using TThis = TCheckAccess;
+    using TBase = TViewerPipeClient;
+    using TBase::ReplyAndPassAway;
+    TAutoPtr<TEvTxProxySchemeCache::TEvNavigateKeySetResult> CacheResult;
+    TVector<TString> Permissions;
+
+public:
+    TCheckAccess(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TViewerPipeClient(viewer, ev)
+    {}
+
+    void Bootstrap() override {
+        const auto& params(Event->Get()->Request.GetParams());
+        ui32 timeout = FromStringWithDefault<ui32>(params.Get("timeout"), 10000);
+        TString database;
+        if (params.Has("database")) {
+            database = params.Get("database");
+        } else {
+            return ReplyAndPassAway(GetHTTPBADREQUEST("text/plain", "field 'database' is required"));
+        }
+        if (database && database != AppData()->TenantName) {
+            BLOG_TRACE("Requesting StateStorageEndpointsLookup for " << database);
+            RequestStateStorageEndpointsLookup(database); // to find some dynamic node and redirect query there
+        } else {
+            if (params.Has("permissions")) {
+                Split(params.Get("permissions"), ",", Permissions);
+            } else {
+                return ReplyAndPassAway(GetHTTPBADREQUEST("text/plain", "field 'permissions' is required"));
+            }
+            if (params.Has("path")) {
+                RequestSchemeCacheNavigate(params.Get("path"));
+            } else {
+                return ReplyAndPassAway(GetHTTPBADREQUEST("text/plain", "field 'path' is required"));
+            }
+        }
+        Become(&TThis::StateRequestedNavigate, TDuration::MilliSeconds(timeout), new TEvents::TEvWakeup());
+    }
+
+    void Handle(TEvStateStorage::TEvBoardInfo::TPtr& ev) {
+        BLOG_TRACE("Received TEvBoardInfo");
+        ReplyAndPassAway(Viewer->MakeForward(Event->Get(), GetNodesFromBoardReply(ev)));
+    }
+
+    STATEFN(StateRequestedNavigate) {
+        switch (ev->GetTypeRewrite()) {
+            hFunc(TEvStateStorage::TEvBoardInfo, Handle);
+            hFunc(TEvTxProxySchemeCache::TEvNavigateKeySetResult, Handle);
+            cFunc(TEvents::TSystem::Wakeup, HandleTimeout);
+        }
+    }
+
+    void Handle(TEvTxProxySchemeCache::TEvNavigateKeySetResult::TPtr& ev) {
+        CacheResult = ev->Release();
+        RequestDone();
+    }
+
+    ui32 GetAccessType(const TString& permission) {
+        TACLAttrs attrs(0);
+        try {
+            attrs = ConvertYdbPermissionNameToACLAttrs(permission);
+        }
+        catch (const std::exception&) {
+        }
+        return attrs.AccessMask;
+    }
+
+    bool CheckAccessPermission(const NACLib::TSecurityObject* object, const NACLib::TUserToken* token, const TString& permission) {
+        const auto& kikimrRunConfig = Viewer->GetKikimrRunConfig();
+        const auto& securityConfig = kikimrRunConfig.AppConfig.GetDomainsConfig().GetSecurityConfig();
+        if (!securityConfig.GetEnforceUserTokenRequirement()) {
+            if (!securityConfig.GetEnforceUserTokenCheckRequirement() || token == nullptr) {
+                return true;
+            }
+        }
+        if (token == nullptr) {
+            return false;
+        }
+        if (object == nullptr) {
+            return false;
+        }
+        ui32 access = GetAccessType(permission);
+        if (access == 0) {
+            return false;
+        }
+        return object->CheckAccess(access, *token);
+    }
+
+    void ReplyAndPassAway() override {
+        std::unique_ptr<NACLib::TUserToken> token;
+        if (Event->Get()->UserToken) {
+            token = std::make_unique<NACLib::TUserToken>(Event->Get()->UserToken);
+        }
+        if (CacheResult == nullptr) {
+            return ReplyAndPassAway(GetHTTPINTERNALERROR("text/plain", "no SchemeCache response"));
+        }
+        if (CacheResult->Request == nullptr) {
+            return ReplyAndPassAway(GetHTTPINTERNALERROR("text/plain", "wrong SchemeCache response"));
+        }
+        if (CacheResult->Request.Get()->ResultSet.empty()) {
+            return ReplyAndPassAway(GetHTTPINTERNALERROR("text/plain", "SchemeCache response is empty"));
+        }
+        if (CacheResult->Request.Get()->ErrorCount != 0) {
+            return ReplyAndPassAway(GetHTTPBADREQUEST("text/plain", TStringBuilder() << "SchemeCache response error " << static_cast<int>(CacheResult->Request.Get()->ResultSet.front().Status)));
+        }
+
+
+        auto object = CacheResult->Request.Get()->ResultSet.front().SecurityObject;
+
+        NJson::TJsonValue json(NJson::JSON_MAP);
+
+        for (const TString& permission : Permissions) {
+            json[permission] = CheckAccessPermission(object.Get(), token.get(), permission);
+        }
+
+        ReplyAndPassAway(GetHTTPOKJSON(json));
+    }
+
+    void HandleTimeout() {
+        ReplyAndPassAway(GetHTTPGATEWAYTIMEOUT("text/plain", "Timeout receiving SchemeCache response"));
+    }
+
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
+            get:
+                tags:
+                  - viewer
+                summary: Check access
+                description: Check access to the specified path
+                parameters:
+                  - name: database
+                    in: query
+                    description: database name
+                    type: string
+                    required: true
+                  - name: path
+                    in: query
+                    description: path to check access
+                    type: string
+                    required: true
+                  - name: permissions
+                    in: query
+                    description: permissions to check
+                    required: true
+                    type: array
+                    items:
+                        type: string
+                        enum:
+                          - ydb.database.connect
+                          - ydb.tables.modify
+                          - ydb.tables.read
+                          - ydb.generic.list
+                          - ydb.generic.read
+                          - ydb.generic.write
+                          - ydb.generic.use_legacy
+                          - ydb.generic.use
+                          - ydb.generic.manage
+                          - ydb.generic.full_legacy
+                          - ydb.generic.full
+                          - ydb.database.create
+                          - ydb.database.drop
+                          - ydb.access.grant
+                          - ydb.granular.select_row
+                          - ydb.granular.update_row
+                          - ydb.granular.erase_row
+                          - ydb.granular.read_attributes
+                          - ydb.granular.write_attributes
+                          - ydb.granular.create_directory
+                          - ydb.granular.create_table
+                          - ydb.granular.create_queue
+                          - ydb.granular.remove_schema
+                          - ydb.granular.describe_schema
+                          - ydb.granular.alter_schema
+                  - name: timeout
+                    in: query
+                    description: timeout in ms
+                    required: false
+                    type: integer
+                responses:
+                    200:
+                        description: OK
+                        content:
+                            application/json:
+                                schema: {}
+                    400:
+                        description: Bad Request
+                    403:
+                        description: Forbidden
+                    504:
+                        description: Gateway Timeout
+            )___");
+
+        return node;
+    }
+};
+
+}
diff --git a/ydb/core/viewer/json_cluster.h b/ydb/core/viewer/viewer_cluster.h
similarity index 88%
rename from ydb/core/viewer/json_cluster.h
rename to ydb/core/viewer/viewer_cluster.h
index c1e7d6e421df..d78f7a2b4d91 100644
--- a/ydb/core/viewer/json_cluster.h
+++ b/ydb/core/viewer/viewer_cluster.h
@@ -1,23 +1,16 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/json/json.h>
+#include "json_handlers.h"
 #include "json_pipe_req.h"
 #include "viewer.h"
-#include "viewer_probes.h"
+#include "viewer_bsgroupinfo.h"
+#include "viewer_pdiskinfo.h"
+#include "viewer_tabletinfo.h"
+#include "viewer_vdiskinfo.h"
 
-LWTRACE_USING(VIEWER_PROVIDER);
-
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
-using ::google::protobuf::FieldDescriptor;
 
 class TJsonCluster : public TViewerPipeClient {
     using TThis = TJsonCluster;
@@ -462,20 +455,6 @@ class TJsonCluster : public TViewerPipeClient {
         TProtoToJson::ProtoToJson(json, pbCluster, JsonSettings);
         Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), std::move(json.Str())), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
 
-        const TInstant now = TActivationContext::Now();
-        LWPROBE(ViewerClusterHandler, TBase::SelfId().NodeId(), Tablets, EventLog.IsTimeout,
-            EventLog.StartTime.MilliSeconds(),
-            (now - EventLog.StartTime).MilliSeconds(),
-            (EventLog.StartHandleListTenantsResponseTime - EventLog.StartTime).MilliSeconds(),
-            (EventLog.StartHandleNodesInfoTime - EventLog.StartTime).MilliSeconds(),
-            (EventLog.StartMergeBSGroupsTime - EventLog.StartTime).MilliSeconds(),
-            (EventLog.StartMergeVDisksTime - EventLog.StartMergeBSGroupsTime).MilliSeconds(),
-            (EventLog.StartMergePDisksTime - EventLog.StartMergeVDisksTime).MilliSeconds(),
-            (EventLog.StartMergeTabletsTime - EventLog.StartMergePDisksTime).MilliSeconds(),
-            (EventLog.StartResponseBuildingTime - EventLog.StartMergeTabletsTime).MilliSeconds(),
-            (now - EventLog.StartResponseBuildingTime).MilliSeconds()
-        );
-
         PassAway();
     }
 
@@ -483,56 +462,37 @@ class TJsonCluster : public TViewerPipeClient {
         EventLog.IsTimeout = true;
         ReplyAndPassAway();
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonCluster> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TClusterInfo>();
-    }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonCluster> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: tablets
-              in: query
-              description: return system tablets state
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonCluster> {
-    static TString GetSummary() {
-        return "Cluster information";
-    }
-};
 
-template <>
-struct TJsonRequestDescription<TJsonCluster> {
-    static TString GetDescription() {
-        return "Returns information about cluster";
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Cluster information",
+            .Description = "Returns information about cluster"
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "tablets",
+            .Description = "return system tablets state",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TClusterInfo>());
+        return yaml;
     }
 };
 
 }
-}
diff --git a/ydb/core/viewer/json_compute.h b/ydb/core/viewer/viewer_compute.h
similarity index 89%
rename from ydb/core/viewer/json_compute.h
rename to ydb/core/viewer/viewer_compute.h
index 21ac3f0a60ea..19ff4a470cbe 100644
--- a/ydb/core/viewer/json_compute.h
+++ b/ydb/core/viewer/viewer_compute.h
@@ -1,25 +1,13 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/base/subdomain.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/cms/console/console.h>
-#include <ydb/core/base/hive.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include "viewer.h"
-#include "viewer_helper.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
+#include "log.h"
+#include "viewer_helper.h"
+#include "viewer_tabletinfo.h"
 #include "wb_aggregate.h"
 #include "wb_merge.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -617,91 +605,72 @@ class TJsonCompute : public TViewerPipeClient {
         Result.AddErrors("Timeout occurred");
         ReplyAndPassAway();
     }
-};
 
-template <>
-struct TJsonRequestSchema<TJsonCompute> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TNetInfo>();
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Compute information",
+            .Description = "Returns information about compute layer of database",
+        });
+        yaml.AddParameter({
+            .Name = "version",
+            .Description = "query version (v1, v2)",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "uptime",
+            .Description = "return only nodes with less uptime in sec.",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "problems_only",
+            .Description = "return only problem nodes",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "filter",
+            .Description = "filter nodes by id or host",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "sort",
+            .Description = "sort by (NodeId,Host,DC,Rack,Version,Uptime,Memory,CPU,LoadAverage)",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "offset",
+            .Description = "skip N nodes",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "limit",
+            .Description = "limit to N nodes",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TComputeInfo>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestParameters<TJsonCompute> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: version
-              in: query
-              description: query version (v1, v2)
-              required: false
-              type: string
-            - name: path
-              in: query
-              description: schema path
-              required: false
-              type: string
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            - name: uptime
-              in: query
-              description: return only nodes with less uptime in sec.
-              required: false
-              type: integer
-            - name: problems_only
-              in: query
-              description: return only problem nodes
-              required: false
-              type: boolean
-            - name: filter
-              in: query
-              description: filter nodes by id or host
-              required: false
-              type: string
-            - name: sort
-              in: query
-              description: sort by (NodeId,Host,DC,Rack,Version,Uptime,Memory,CPU,LoadAverage)
-              required: false
-              type: string
-            - name: offset
-              in: query
-              description: skip N nodes
-              required: false
-              type: integer
-            - name: limit
-              in: query
-              description: limit to N nodes
-              required: false
-              type: integer
-        )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonCompute> {
-    static TString GetSummary() {
-        return "Database compute information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonCompute> {
-    static TString GetDescription() {
-        return "Returns information about compute layer of database";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_config.h b/ydb/core/viewer/viewer_config.h
similarity index 62%
rename from ydb/core/viewer/json_config.h
rename to ydb/core/viewer/viewer_config.h
index e239c82fc4f8..b8e68bcd305e 100644
--- a/ydb/core/viewer/json_config.h
+++ b/ydb/core/viewer/viewer_config.h
@@ -1,14 +1,10 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/hive.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
+#include "json_handlers.h"
 #include "viewer.h"
+#include <ydb/core/viewer/yaml/yaml.h>
+#include <ydb/library/actors/core/actor_bootstrapped.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -38,28 +34,17 @@ class TJsonConfig : public TActorBootstrapped<TJsonConfig> {
         ctx.Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), json.Str()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         Die(ctx);
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonConfig> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrConfig::TAppConfig>();
-    }
-};
 
-template <>
-struct TJsonRequestSummary<TJsonConfig> {
-    static TString GetSummary() {
-        return "Configuration";
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Configuration",
+            .Description = "Returns configuration",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrConfig::TAppConfig>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestDescription<TJsonConfig> {
-    static TString GetDescription() {
-        return "Returns configuration";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_content.h b/ydb/core/viewer/viewer_content.h
similarity index 70%
rename from ydb/core/viewer/json_content.h
rename to ydb/core/viewer/viewer_content.h
index 0d9399d36022..1ce656981f29 100644
--- a/ydb/core/viewer/json_content.h
+++ b/ydb/core/viewer/viewer_content.h
@@ -1,17 +1,10 @@
-#pragma once
-#include <unordered_map>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include "viewer.h"
 #include "browse.h"
+#include "json_handlers.h"
+#include "viewer.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
-using ::google::protobuf::FieldDescriptor;
 
 class TJsonContent : public TActorBootstrapped<TJsonContent> {
     using TThis = TJsonContent;
@@ -135,65 +128,52 @@ class TJsonContent : public TActorBootstrapped<TJsonContent> {
 
         Die(ctx);
     }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonContent> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: path
-              in: query
-              description: schema path
-              required: true
-              type: string
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: key
-              in: query
-              description: key for positioning
-              required: false
-              type: string
-            - name: limit
-              in: query
-              description: rows limit
-              required: false
-              type: integer
-            - name: offset
-              in: query
-              description: offset in rows
-              required: false
-              type: integer
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-        )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonContent> {
-    static TString GetSummary() {
-        return "Schema content preview";
-    }
-};
 
-template <>
-struct TJsonRequestDescription<TJsonContent> {
-    static TString GetDescription() {
-        return "Return schema preview";
+public:
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "obsolete",
+            .Summary = "Schema content preview",
+            .Description = "Return schema preview"
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "key",
+            .Description = "key for positioning",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "limit",
+            .Description = "rows limit",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "offset",
+            .Description = "offset in rows",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        return yaml;
     }
 };
 
-
-}
 }
diff --git a/ydb/core/viewer/json_counters.h b/ydb/core/viewer/viewer_counters.h
similarity index 97%
rename from ydb/core/viewer/json_counters.h
rename to ydb/core/viewer/viewer_counters.h
index 8ad296bcbe43..6bb10f92d5ce 100644
--- a/ydb/core/viewer/json_counters.h
+++ b/ydb/core/viewer/viewer_counters.h
@@ -1,14 +1,12 @@
 #pragma once
-#include <unordered_map>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
+#include "json_handlers.h"
 #include "viewer.h"
-#include "json_tabletinfo.h"
+#include "viewer_bsgroupinfo.h"
+#include "viewer_pdiskinfo.h"
+#include "viewer_tabletinfo.h"
+#include "viewer_vdiskinfo.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using ::google::protobuf::FieldDescriptor;
@@ -433,7 +431,17 @@ class TJsonCounters : public TActorBootstrapped<TJsonCounters> {
         ctx.Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         Die(ctx);
     }
+
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "counters",
+            .Description = "counters",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TStorageUsageStats>());
+        return yaml;
+    }
 };
 
 }
-}
diff --git a/ydb/core/viewer/json_describe.h b/ydb/core/viewer/viewer_describe.h
similarity index 78%
rename from ydb/core/viewer/json_describe.h
rename to ydb/core/viewer/viewer_describe.h
index 27280609dda4..bac7c46aec89 100644
--- a/ydb/core/viewer/json_describe.h
+++ b/ydb/core/viewer/viewer_describe.h
@@ -1,17 +1,11 @@
 #pragma once
-#include <ydb/core/tx/scheme_board/cache.h>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/external_sources/external_source_factory.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
+#include "log.h"
+#include "viewer.h"
+#include <ydb/core/external_sources/external_source_factory.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using NSchemeShard::TEvSchemeShard;
@@ -20,8 +14,7 @@ using TNavigate = NSchemeCache::TSchemeCacheNavigate;
 class TJsonDescribe : public TViewerPipeClient {
     using TThis = TJsonDescribe;
     using TBase = TViewerPipeClient;
-    IViewer* Viewer;
-    NMon::TEvHttpInfo::TPtr Event;
+    using TBase::ReplyAndPassAway;
     TAutoPtr<TEvSchemeShard::TEvDescribeSchemeResult> SchemeShardResult;
     TAutoPtr<TEvTxProxySchemeCache::TEvNavigateKeySetResult> CacheResult;
     TAutoPtr<NKikimrViewer::TEvDescribeSchemeInfo> DescribeResult;
@@ -31,9 +24,8 @@ class TJsonDescribe : public TViewerPipeClient {
     int Requests = 0;
 
 public:
-    TJsonDescribe(IViewer* viewer, NMon::TEvHttpInfo::TPtr &ev)
-        : Viewer(viewer)
-        , Event(ev)
+    TJsonDescribe(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TViewerPipeClient(viewer, ev)
     {}
 
     void FillParams(NKikimrSchemeOp::TDescribePath* record, const TCgiParameters& params) {
@@ -269,8 +261,7 @@ class TJsonDescribe : public TViewerPipeClient {
             json << "null";
         }
 
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), json.Str()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
+        ReplyAndPassAway(GetHTTPOKJSON(json.Str()));
     }
 
     void DecodeExternalTableContent(TStringStream& json) const {
@@ -310,111 +301,91 @@ class TJsonDescribe : public TViewerPipeClient {
     }
 
     void HandleTimeout() {
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
+        ReplyAndPassAway(GetHTTPGATEWAYTIMEOUT());
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonDescribe> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NSchemeShard::TEvSchemeShard::TEvDescribeSchemeResult::ProtoRecordType>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonDescribe> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: path
-              in: query
-              description: schema path
-              required: false
-              type: string
-            - name: schemeshard_id
-              in: query
-              description: schemeshard identifier (tablet id)
-              required: false
-              type: integer
-            - name: path_id
-              in: query
-              description: path id
-              required: false
-              type: integer
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: backup
-              in: query
-              description: return backup information
-              required: false
-              type: boolean
-              default: true
-            - name: private
-              in: query
-              description: return private tables
-              required: false
-              type: boolean
-              default: true
-            - name: children
-              in: query
-              description: return children
-              required: false
-              type: boolean
-              default: true
-            - name: boundaries
-              in: query
-              description: return boundaries
-              required: false
-              type: boolean
-              default: false
-            - name: partition_config
-              in: query
-              description: return partition configuration
-              required: false
-              type: boolean
-              default: true
-            - name: partition_stats
-              in: query
-              description: return partitions statistics
-              required: false
-              type: boolean
-              default: false
-            - name: partitioning_info
-              in: query
-              description: return partitioning information
-              required: false
-              type: boolean
-              default: true
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Schema detailed information",
+            .Description = "Returns detailed information about schema object"
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "schemeshard_id",
+            .Description = "schemeshard identifier (tablet id)",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "path_id",
+            .Description = "path id",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "backup",
+            .Description = "return backup information",
+            .Type = "boolean",
+            .Default = "true",
+        });
+        yaml.AddParameter({
+            .Name = "private",
+            .Description = "return private tables",
+            .Type = "boolean",
+            .Default = "true",
+        });
+        yaml.AddParameter({
+            .Name = "children",
+            .Description = "return children",
+            .Type = "boolean",
+            .Default = "true",
+        });
+        yaml.AddParameter({
+            .Name = "boundaries",
+            .Description = "return boundaries",
+            .Type = "boolean",
+            .Default = "false",
+        });
+        yaml.AddParameter({
+            .Name = "partition_config",
+            .Description = "return partition configuration",
+            .Type = "boolean",
+            .Default = "true",
+        });
+        yaml.AddParameter({
+            .Name = "partition_stats",
+            .Description = "return partitions statistics",
+            .Type = "boolean",
+            .Default = "false",
+        });
+        yaml.AddParameter({
+            .Name = "partitioning_info",
+            .Description = "return partitioning information",
+            .Type = "boolean",
+            .Default = "true",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TEvDescribeSchemeInfo>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonDescribe> {
-    static TString GetSummary() {
-        return "Schema detailed information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonDescribe> {
-    static TString GetDescription() {
-        return "Returns detailed information about schema object";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/viewer_describe_consumer.h b/ydb/core/viewer/viewer_describe_consumer.h
new file mode 100644
index 000000000000..bdc4f0d84516
--- /dev/null
+++ b/ydb/core/viewer/viewer_describe_consumer.h
@@ -0,0 +1,105 @@
+#pragma once
+#include "json_handlers.h"
+#include "json_local_rpc.h"
+#include <ydb/core/grpc_services/rpc_calls_topic.h>
+#include <ydb/public/api/grpc/ydb_topic_v1.grpc.pb.h>
+
+namespace NKikimr::NViewer {
+
+using TDescribeConsumerRpc = TJsonLocalRpc<Ydb::Topic::DescribeConsumerRequest,
+                                         Ydb::Topic::DescribeConsumerResponse,
+                                         Ydb::Topic::DescribeConsumerResult,
+                                         Ydb::Topic::V1::TopicService,
+                                         NKikimr::NGRpcService::TEvDescribeConsumerRequest>;
+
+class TJsonDescribeConsumer : public TDescribeConsumerRpc {
+public:
+    using TBase = TDescribeConsumerRpc;
+
+    TJsonDescribeConsumer(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TBase(viewer, ev)
+    {}
+
+    void Bootstrap() override {
+        if (Event->Get()->Request.GetMethod() != HTTP_METHOD_GET) {
+            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "Only GET method is allowed"));
+        }
+        const auto& params(Event->Get()->Request.GetParams());
+        if (params.Has("database")) {
+            Database = params.Get("database");
+        } else if (params.Has("database_path")) {
+            Database = params.Get("database_path");
+        } else {
+            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "field 'database' is required"));
+        }
+
+        if (params.Has("consumer")) {
+            Request.set_consumer(params.Get("consumer"));
+        } else {
+            return ReplyAndPassAway(Viewer->GetHTTPBADREQUEST(Event->Get(), "text/plain", "field 'consumer' is required"));
+        }
+
+        if (params.Has("include_stats")) {
+            Request.set_include_stats(FromStringWithDefault<bool>(params.Get("include_stats"), false));
+        }
+
+        TBase::Bootstrap();
+    }
+
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
+            get:
+              tags:
+              - viewer
+              summary: Topic schema detailed information
+              description: Returns detailed information about topic
+              parameters:
+              - name: database
+                in: query
+                description: database name
+                required: true
+                type: string
+              - name: consumer
+                in: query
+                description: consumer name
+                required: true
+                type: string
+              - name: include_stats
+                in: query
+                description: include stat flag
+                required: false
+                type: bool
+              - name: timeout
+                in: query
+                description: timeout in ms
+                required: false
+                type: integer
+              - name: enums
+                in: query
+                description: convert enums to strings
+                required: false
+                type: boolean
+              - name: ui64
+                in: query
+                description: return ui64 as number
+                required: false
+                type: boolean
+              responses:
+                200:
+                  description: OK
+                  content:
+                    application/json:
+                      schema: {}
+                400:
+                  description: Bad Request
+                403:
+                  description: Forbidden
+                504:
+                  description: Gateway Timeout
+            )___");
+        node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Topic::DescribeConsumerResult>();
+        return node;
+    }
+};
+
+}
diff --git a/ydb/core/viewer/json_describe_topic.h b/ydb/core/viewer/viewer_describe_topic.h
similarity index 50%
rename from ydb/core/viewer/json_describe_topic.h
rename to ydb/core/viewer/viewer_describe_topic.h
index 2a7a8fb418dc..5e94d20097b5 100644
--- a/ydb/core/viewer/json_describe_topic.h
+++ b/ydb/core/viewer/viewer_describe_topic.h
@@ -1,10 +1,9 @@
-#pragma once
-#include <ydb/public/api/grpc/ydb_topic_v1.grpc.pb.h>
-#include <ydb/core/grpc_services/rpc_calls_topic.h>
+#include "json_handlers.h"
 #include "json_local_rpc.h"
+#include <ydb/core/grpc_services/rpc_calls_topic.h>
+#include <ydb/public/api/grpc/ydb_topic_v1.grpc.pb.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using TDescribeTopicRpc = TJsonLocalRpc<Ydb::Topic::DescribeTopicRequest,
                                          Ydb::Topic::DescribeTopicResponse,
@@ -45,63 +44,49 @@ class TJsonDescribeTopic : public TDescribeTopicRpc {
 
         TBase::Bootstrap();
     }
-};
 
-template<>
-YAML::Node TJsonRequestSwagger<TJsonDescribeTopic>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
-        get:
-          tags:
-          - viewer
-          summary: Topic schema detailed information
-          description: Returns detailed information about topic
-          parameters:
-          - name: database
-            in: query
-            description: database name
-            required: true
-            type: string
-          - name: path
-            in: query
-            description: schema path
-            required: true
-            type: string
-          - name: include_stats
-            in: query
-            description: include stat flag
-            required: false
-            type: bool
-          - name: timeout
-            in: query
-            description: timeout in ms
-            required: false
-            type: integer
-          - name: enums
-            in: query
-            description: convert enums to strings
-            required: false
-            type: boolean
-          - name: ui64
-            in: query
-            description: return ui64 as number
-            required: false
-            type: boolean
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema: {}
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-    node["get"]["responses"]["200"]["content"]["application/json"]["schema"] = TProtoToYaml::ProtoToYamlSchema<Ydb::Topic::DescribeTopicResult>();
-    return node;
-}
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Topic schema detailed information",
+            .Description = "Returns detailed information about topic",
+        });
+        yaml.AddParameter({
+            .Name = "database",
+            .Description = "database name",
+            .Type = "string",
+            .Required = true,
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+            .Required = true,
+        });
+        yaml.AddParameter({
+            .Name = "include_stats",
+            .Description = "include stat flag",
+            .Type = "bool",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Required = false,
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<Ydb::Topic::DescribeTopicResult>());
+        return yaml;
+    }
+};
 
 }
-}
diff --git a/ydb/core/viewer/json_graph.h b/ydb/core/viewer/viewer_graph.h
similarity index 60%
rename from ydb/core/viewer/json_graph.h
rename to ydb/core/viewer/viewer_graph.h
index 20fa68980227..de5de41ba1da 100644
--- a/ydb/core/viewer/json_graph.h
+++ b/ydb/core/viewer/viewer_graph.h
@@ -1,33 +1,27 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/graph/api/service.h>
-#include <ydb/core/graph/api/events.h>
-#include <library/cpp/json/json_writer.h>
-#include "viewer.h"
+#include "json_handlers.h"
+#include "json_pipe_req.h"
 #include "log.h"
+#include "viewer.h"
+#include <ydb/core/graph/api/events.h>
+#include <ydb/core/graph/api/service.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
-class TJsonGraph : public TActorBootstrapped<TJsonGraph> {
-    IViewer* Viewer;
-    NMon::TEvHttpInfo::TPtr Event;
+class TJsonGraph : public TViewerPipeClient {
+    using TThis = TJsonGraph;
+    using TBase = TViewerPipeClient;
+    using TBase::ReplyAndPassAway;
     std::vector<TString> Metrics;
 
 public:
-    static constexpr NKikimrServices::TActivity::EType ActorActivityType() {
-        return NKikimrServices::TActivity::VIEWER_HANDLER;
-    }
-
-    TJsonGraph(IViewer* viewer, NMon::TEvHttpInfo::TPtr &ev)
-        : Viewer(viewer)
-        , Event(ev)
+    TJsonGraph(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TViewerPipeClient(viewer, ev)
     {}
 
-    void Bootstrap() {
+    void Bootstrap() override {
         BLOG_TRACE("Graph received request for " << Event->Get()->Request.GetUri());
         const auto& params(Event->Get()->Request.GetParams());
         NKikimrGraph::TEvGetMetrics getRequest;
@@ -37,8 +31,7 @@ class TJsonGraph : public TActorBootstrapped<TJsonGraph> {
                 getRequest.AddMetrics(metric);
             }
         } else {
-            Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPBADREQUEST(Event->Get(), {}, "Bad Request"), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-            return PassAway();
+            return ReplyAndPassAway(GetHTTPBADREQUEST("text/plain", "no 'target' parameter specified"));
         }
         if (params.Has("from")) {
             getRequest.SetTimeFrom(FromStringWithDefault<ui32>(params.Get("from")));
@@ -57,7 +50,7 @@ class TJsonGraph : public TActorBootstrapped<TJsonGraph> {
     STATEFN(StateWork) {
         switch (ev->GetTypeRewrite()) {
             hFunc(NGraph::TEvGraph::TEvMetricsResult, Handle);
-            cFunc(TEvents::TSystem::Wakeup, Timeout);
+            cFunc(TEvents::TSystem::Wakeup, HandleTimeout);
         }
     }
 
@@ -69,22 +62,19 @@ class TJsonGraph : public TActorBootstrapped<TJsonGraph> {
         if (response.GetError()) {
             json["status"] = "error";
             json["error"] = response.GetError();
-            Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-            return PassAway();
+            return ReplyAndPassAway(GetHTTPOKJSON(json));
         }
         if (response.DataSize() != Metrics.size()) {
             json["status"] = "error";
             json["error"] = "Invalid data size received";
-            Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-            return PassAway();
+            return ReplyAndPassAway(GetHTTPOKJSON(json));
         }
         for (size_t nMetric = 0; nMetric < response.DataSize(); ++nMetric) {
             const auto& protoMetric(response.GetData(nMetric));
             if (response.TimeSize() != protoMetric.ValuesSize()) {
                 json["status"] = "error";
                 json["error"] = "Invalid value size received";
-                Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-                return PassAway();
+                return ReplyAndPassAway(GetHTTPOKJSON(json));
             }
         }
         if (!params.Has("format") || params.Get("format") == "graphite") { // graphite
@@ -133,62 +123,46 @@ class TJsonGraph : public TActorBootstrapped<TJsonGraph> {
             }
         }
 
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
+        ReplyAndPassAway(GetHTTPOKJSON(json));
     }
 
-    void Timeout() {
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
-    }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonGraph> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-                - name: target
-                  in: query
-                  description: metrics comma delimited
-                  required: true
-                  type: string
-                - name: from
-                  in: query
-                  description: time in seconds
-                  required: false
-                  type: integer
-                - name: until
-                  in: query
-                  description: time in seconds
-                  required: false
-                  type: integer
-                - name: maxDataPoints
-                  in: query
-                  description: maximum number of data points
-                  required: false
-                  type: integer
-                - name: format
-                  in: query
-                  description: response format, could be prometheus or graphite
-                  required: false
-                  type: string
-            )___");
-    }
-};
+    void ReplyAndPassAway() override {}
 
-template <>
-struct TJsonRequestSummary<TJsonGraph> {
-    static TString GetSummary() {
-        return "Graph data";
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Graph data",
+            .Description = "Returns graph data",
+        });
+        yaml.AddParameter({
+            .Name = "target",
+            .Description = "metrics comma delimited",
+            .Type = "string",
+            .Required = true,
+        });
+        yaml.AddParameter({
+            .Name = "from",
+            .Description = "time in seconds",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "until",
+            .Description = "time in seconds",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "maxDataPoints",
+            .Description = "maximum number of data points",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "format",
+            .Description = "response format, could be prometheus or graphite",
+            .Type = "string",
+        });
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestDescription<TJsonGraph> {
-    static TString GetDescription() {
-        return "Returns graph data";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_healthcheck.h b/ydb/core/viewer/viewer_healthcheck.h
similarity index 78%
rename from ydb/core/viewer/json_healthcheck.h
rename to ydb/core/viewer/viewer_healthcheck.h
index 1d0d54415ad8..6bd447ef6b82 100644
--- a/ydb/core/viewer/json_healthcheck.h
+++ b/ydb/core/viewer/viewer_healthcheck.h
@@ -1,24 +1,15 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/grpc_services/db_metadata_cache.h>
-#include <ydb/library/services/services.pb.h>
+#include "healthcheck_record.h"
+#include "json_handlers.h"
+#include "json_pipe_req.h"
 #include "viewer.h"
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/health_check/health_check.h>
-#include <ydb/core/util/proto_duration.h>
 #include <library/cpp/monlib/encode/prometheus/prometheus.h>
-#include <util/string/split.h>
-#include "json_pipe_req.h"
-#include "healthcheck_record.h"
-#include <vector>
+#include <ydb/core/util/proto_duration.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
+using namespace NMonitoring;
 
 enum HealthCheckResponseFormat {
     JSON,
@@ -99,7 +90,10 @@ class TJsonHealthCheck : public TViewerPipeClient {
             JsonSettings.EnumAsNumbers = !FromStringWithDefault<bool>(params.Get("enums"), true);
             JsonSettings.UI64AsString = !FromStringWithDefault<bool>(params.Get("ui64"), false);
         }
-        Database = params.Get("tenant");
+        Database = params.Get("database");
+        if (Database.empty()) {
+            Database = params.Get("tenant");
+        }
         Cache = FromStringWithDefault<bool>(params.Get("cache"), Cache);
         MergeRecords = FromStringWithDefault<bool>(params.Get("merge_records"), MergeRecords);
         Timeout = FromStringWithDefault<ui32>(params.Get("timeout"), 10000);
@@ -252,86 +246,67 @@ class TJsonHealthCheck : public TViewerPipeClient {
         Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         PassAway();
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonHealthCheck> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<Ydb::Monitoring::SelfCheckResult>();
-    }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonHealthCheck> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            - name: tenant
-              in: query
-              description: path to database
-              required: false
-              type: string
-            - name: cache
-              in: query
-              description: use cache
-              required: false
-              type: boolean
-            - name: verbose
-              in: query
-              description: return verbose status
-              required: false
-              type: boolean
-            - name: merge_records
-              in: query
-              description: merge records
-              required: false
-              type: boolean
-            - name: max_level
-              in: query
-              description: max depth of issues to return
-              required: false
-              type: integer
-            - name: min_status
-              in: query
-              description: min status of issues to return
-              required: false
-              type: string
-            - name: format
-              in: query
-              description: format of reply
-              required: false
-              type: string
-            )___");
-    }
-};
 
-template <>
-struct TJsonRequestSummary<TJsonHealthCheck> {
-    static TString GetSummary() {
-        return "Self-check result";
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Self-check result",
+            .Description = "Performs self-check and returns result",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "database",
+            .Description = "database name",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "cache",
+            .Description = "use cache",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "verbose",
+            .Description = "return verbose status",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "merge_records",
+            .Description = "merge records",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "max_level",
+            .Description = "max depth of issues to return",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "min_status",
+            .Description = "min status of issues to return",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "format",
+            .Description = "format of reply",
+            .Type = "string",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<Ydb::Monitoring::SelfCheckResult>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestDescription<TJsonHealthCheck> {
-    static TString GetDescription() {
-        return "Performs self-check and returns result";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/viewer_helper.h b/ydb/core/viewer/viewer_helper.h
index 1d92ac7570f1..2786e410ef03 100644
--- a/ydb/core/viewer/viewer_helper.h
+++ b/ydb/core/viewer/viewer_helper.h
@@ -1,5 +1,4 @@
 #pragma once
-
 #include <util/generic/algorithm.h>
 
 namespace NKikimr::NViewer {
diff --git a/ydb/core/viewer/json_hiveinfo.h b/ydb/core/viewer/viewer_hiveinfo.h
similarity index 51%
rename from ydb/core/viewer/json_hiveinfo.h
rename to ydb/core/viewer/viewer_hiveinfo.h
index a93458369d3c..197024042701 100644
--- a/ydb/core/viewer/json_hiveinfo.h
+++ b/ydb/core/viewer/viewer_hiveinfo.h
@@ -1,33 +1,24 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/hive.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
-#include <ydb/core/viewer/json/json.h>
+#include "viewer.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
 class TJsonHiveInfo : public TViewerPipeClient {
     using TThis = TJsonHiveInfo;
     using TBase = TViewerPipeClient;
-    IViewer* Viewer;
-    NMon::TEvHttpInfo::TPtr Event;
+    using TBase::ReplyAndPassAway;
     TAutoPtr<TEvHive::TEvResponseHiveInfo> HiveInfo;
     TJsonSettings JsonSettings;
     ui32 Timeout = 0;
     TNodeId NodeId = 0;
 
 public:
-    TJsonHiveInfo(IViewer* viewer, NMon::TEvHttpInfo::TPtr &ev)
-        : Viewer(viewer)
-        , Event(ev)
+    TJsonHiveInfo(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TViewerPipeClient(viewer, ev)
     {}
 
     void Bootstrap() override {
@@ -88,84 +79,60 @@ class TJsonHiveInfo : public TViewerPipeClient {
         } else {
             json << "null";
         }
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), json.Str()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
-    }
-
-    void HandleTimeout() {
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
+        ReplyAndPassAway(GetHTTPOKJSON(json.Str()));
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonHiveInfo> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<TEvHive::TEvResponseHiveInfo::ProtoRecordType>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonHiveInfo> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: hive_id
-              in: query
-              description: hive identifier (tablet id)
-              required: true
-              type: string
-            - name: tablet_id
-              in: query
-              description: tablet id filter
-              required: false
-              type: string
-            - name: tablet_type
-              in: query
-              description: tablet type filter
-              required: false
-              type: string
-            - name: followers
-              in: query
-              description: return followers
-              required: false
-              type: boolean
-            - name: metrics
-              in: query
-              description: return tablet metrics
-              required: false
-              type: boolean
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Hive Info",
+            .Description = "Returns information about the hive",
+        });
+        yaml.AddParameter({
+            .Name = "hive_id",
+            .Description = "hive identifier (tablet id)",
+            .Type = "string",
+            .Required = true,
+        });
+        yaml.AddParameter({
+            .Name = "tablet_id",
+            .Description = "tablet id filter",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "tablet_type",
+            .Description = "tablet type filter",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "followers",
+            .Description = "return followers",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "metrics",
+            .Description = "return tablet metrics",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrHive::TEvResponseHiveInfo>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonHiveInfo> {
-    static TString GetSummary() {
-        return "Hive information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonHiveInfo> {
-    static TString GetDescription() {
-        return "Returns information about tablets from Hive";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_hivestats.h b/ydb/core/viewer/viewer_hivestats.h
similarity index 56%
rename from ydb/core/viewer/json_hivestats.h
rename to ydb/core/viewer/viewer_hivestats.h
index d1529630df59..80cee5c512a1 100644
--- a/ydb/core/viewer/json_hivestats.h
+++ b/ydb/core/viewer/viewer_hivestats.h
@@ -1,16 +1,8 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/hive.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
-#include <ydb/core/viewer/json/json.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -74,66 +66,47 @@ class TJsonHiveStats : public TViewerPipeClient {
         Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         PassAway();
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonHiveStats> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<TEvHive::TEvResponseHiveDomainStats::ProtoRecordType>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonHiveStats> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: hive_id
-              in: query
-              description: hive identifier (tablet id)
-              required: true
-              type: string
-            - name: followers
-              in: query
-              description: return followers
-              required: false
-              type: boolean
-            - name: metrics
-              in: query
-              description: return tablet metrics
-              required: false
-              type: boolean
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Hive statistics",
+            .Description = "Returns information about Hive statistics",
+        });
+        yaml.AddParameter({
+            .Name = "hive_id",
+            .Description = "hive identifier (tablet id)",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "followers",
+            .Description = "return followers",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "metrics",
+            .Description = "return tablet metrics",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TEvHive::TEvResponseHiveDomainStats::ProtoRecordType>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonHiveStats> {
-    static TString GetSummary() {
-        return "Hive statistics";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonHiveStats> {
-    static TString GetDescription() {
-        return "Returns information about Hive statistics";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_hotkeys.h b/ydb/core/viewer/viewer_hotkeys.h
similarity index 79%
rename from ydb/core/viewer/json_hotkeys.h
rename to ydb/core/viewer/viewer_hotkeys.h
index a0e67a5d8389..4fef525e7c9f 100644
--- a/ydb/core/viewer/json_hotkeys.h
+++ b/ydb/core/viewer/viewer_hotkeys.h
@@ -1,18 +1,9 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/datashard/datashard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <util/generic/hash.h>
-#include <util/generic/fwd.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
+#include <ydb/core/tx/datashard/datashard.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using NSchemeShard::TEvSchemeShard;
@@ -21,8 +12,7 @@ class TJsonHotkeys : public TViewerPipeClient {
     static const bool WithRetry = false;
     using TThis = TJsonHotkeys;
     using TBase = TViewerPipeClient;
-    IViewer* Viewer;
-    NMon::TEvHttpInfo::TPtr Event;
+    using TBase::ReplyAndPassAway;
     TAutoPtr<TEvSchemeShard::TEvDescribeSchemeResult> DescribeResult;
     ui32 Timeout = 0;
     ui32 Limit = 0;
@@ -38,9 +28,8 @@ class TJsonHotkeys : public TViewerPipeClient {
     TMultiSet<std::pair<ui64, TVector<TString>>, KeysComparator> Keys;
 
 public:
-    TJsonHotkeys(IViewer* viewer, NMon::TEvHttpInfo::TPtr &ev)
-        : Viewer(viewer)
-        , Event(ev)
+    TJsonHotkeys(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TViewerPipeClient(viewer, ev)
     {}
 
     void FillParams(NKikimrSchemeOp::TDescribePath* record, const TCgiParameters& params) {
@@ -142,25 +131,49 @@ class TJsonHotkeys : public TViewerPipeClient {
         if (DescribeResult != nullptr) {
             switch (DescribeResult->GetRecord().GetStatus()) {
             case NKikimrScheme::StatusAccessDenied:
-                Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPFORBIDDEN(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-                PassAway();
-                return;
+                return ReplyAndPassAway(GetHTTPFORBIDDEN());
             default:
                 break;
             }
         }
         NJson::TJsonValue root = BuildResponse();
-        TString json = NJson::WriteJson(root, false);
-
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), json), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
+        ReplyAndPassAway(GetHTTPOKJSON(root));
     }
 
-    void HandleTimeout() {
-        Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
-        PassAway();
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Information about current hot keys in a datashard",
+            .Description = "Samples and returns information about current hot keys",
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "path to the table",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "enable_sampling",
+            .Description = "enable sampling",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "polling_factor",
+            .Description = "polling factor",
+            .Type = "float",
+        });
+        yaml.AddParameter({
+            .Name = "limit",
+            .Description = "limit of hot keys",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        return yaml;
     }
 };
 
 }
-}
diff --git a/ydb/core/viewer/json_labeledcounters.h b/ydb/core/viewer/viewer_labeled_counters.h
similarity index 69%
rename from ydb/core/viewer/json_labeledcounters.h
rename to ydb/core/viewer/viewer_labeled_counters.h
index c8ea014b6205..f2a9272d30c1 100644
--- a/ydb/core/viewer/json_labeledcounters.h
+++ b/ydb/core/viewer/viewer_labeled_counters.h
@@ -1,15 +1,12 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
+#include "json_handlers.h"
+#include "viewer.h"
 #include <ydb/core/tablet/tablet_counters_aggregator.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
 #include <ydb/core/util/wildcard.h>
-#include "viewer.h"
+#include <ydb/library/actors/core/actor_bootstrapped.h>
+#include <ydb/library/persqueue/topic_parser_public/topic_parser.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -47,7 +44,7 @@ class TJsonLabeledCounters : public TActorBootstrapped<TJsonLabeledCounters> {
         Topic = NPersQueue::ConvertNewTopicName(params.Get("topic"));
         if (Topic.empty())
             Topic = "*";
-        Consumer = NPersQueue::ConvertNewConsumerName(params.Get("consumer"), ctx);
+        Consumer = NPersQueue::ConvertNewConsumerName(params.Get("consumer"));
         DC = params.Get("dc");
         if (DC.empty())
             DC = "*";
@@ -145,93 +142,71 @@ class TJsonLabeledCounters : public TActorBootstrapped<TJsonLabeledCounters> {
         ctx.Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         Die(ctx);
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonLabeledCounters> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<TEvTabletCounters::TEvTabletLabeledCountersResponse::ProtoRecordType>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonLabeledCounters> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: group
-              in: query
-              description: group name
-              required: false
-              type: string
-            - name: dc
-              in: query
-              description: datacenter name
-              required: false
-              type: string
-              default: "*"
-            - name: topic
-              in: query
-              description: topic name
-              required: false
-              type: string
-              default: "*"
-            - name: consumer
-              in: query
-              description: consumer name
-              required: false
-              type: string
-              default: ""
-            - name: group_names
-              in: query
-              description: group names
-              required: false
-              type: string
-            - name: counters
-              in: query
-              description: counters names
-              required: false
-              type: string
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-              default: false
-            - name: all
-              in: query
-              description: return information about all topics and clients
-              required: false
-              type: boolean
-              default: false
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-              default: false
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-              default: 10000
-            )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Labeled counters info",
+            .Description = "Returns information about labeled counters",
+        });
+        yaml.AddParameter({
+            .Name = "group",
+            .Description = "group name",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "dc",
+            .Description = "datacenter name",
+            .Type = "string",
+            .Default = "*",
+        });
+        yaml.AddParameter({
+            .Name = "topic",
+            .Description = "topic name",
+            .Type = "string",
+            .Default = "*",
+        });
+        yaml.AddParameter({
+            .Name = "consumer",
+            .Description = "consumer name",
+            .Type = "string",
+            .Default = "",
+        });
+        yaml.AddParameter({
+            .Name = "group_names",
+            .Description = "group names",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "counters",
+            .Description = "counters names",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "all",
+            .Description = "return information about all topics and clients",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+            .Default = "10000",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TEvTabletCounters::TEvTabletLabeledCountersResponse::ProtoRecordType>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonLabeledCounters> {
-    static TString GetSummary() {
-        return "Labeled counters info";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonLabeledCounters> {
-    static TString GetDescription() {
-        return "Returns information about labeled counters";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_metainfo.h b/ydb/core/viewer/viewer_metainfo.h
similarity index 66%
rename from ydb/core/viewer/json_metainfo.h
rename to ydb/core/viewer/viewer_metainfo.h
index b96a26a4478a..dcd7a12629e4 100644
--- a/ydb/core/viewer/json_metainfo.h
+++ b/ydb/core/viewer/viewer_metainfo.h
@@ -1,25 +1,9 @@
-#pragma once
-#include <unordered_map>
-#include <unordered_set>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/appdata.h>
-#include <ydb/core/base/domain.h>
-#include <ydb/core/base/hive.h>
-#include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tablet/tablet_counters_aggregator.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
 #include "browse.h"
-#include <ydb/core/viewer/json/json.h>
+#include "json_handlers.h"
 #include "viewer.h"
 #include "wb_aggregate.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -124,66 +108,42 @@ class TJsonMetaInfo : public TActorBootstrapped<TJsonMetaInfo> {
             html << request << Endl;
         }
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonMetaInfo> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TMetaInfo>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonMetaInfo> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: path
-              in: query
-              description: schema path
-              required: false
-              type: string
-            - name: tablet_id
-              in: query
-              description: tablet identifier
-              required: false
-              type: integer
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: counters
-              in: query
-              description: return tablet counters
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "obsolete",
+            .Summary = "Schema meta information",
+            .Description = "Returns meta information about schema path",
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "counters",
+            .Description = "return tablet counters",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TMetaInfo>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonMetaInfo> {
-    static TString GetSummary() {
-        return "Schema meta information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonMetaInfo> {
-    static TString GetDescription() {
-        return "Returns meta information about schema path";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_netinfo.h b/ydb/core/viewer/viewer_netinfo.h
similarity index 86%
rename from ydb/core/viewer/json_netinfo.h
rename to ydb/core/viewer/viewer_netinfo.h
index c10cd7d745f5..edddfa3010b8 100644
--- a/ydb/core/viewer/json_netinfo.h
+++ b/ydb/core/viewer/viewer_netinfo.h
@@ -1,24 +1,11 @@
-#pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/base/subdomain.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/cms/console/console.h>
-#include <ydb/core/base/hive.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
+#include "viewer.h"
 #include "wb_aggregate.h"
 #include "wb_merge.h"
+#include <ydb/library/actors/interconnect/interconnect.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -294,61 +281,42 @@ class TJsonNetInfo : public TViewerPipeClient {
         Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         PassAway();
     }
-};
 
-template <>
-struct TJsonRequestSchema<TJsonNetInfo> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TNetInfo>();
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Network information",
+            .Description = "Returns network information",
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "hive_id",
+            .Description = "hive identifier (tablet id)",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TNetInfo>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestParameters<TJsonNetInfo> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-              - name: path
-                in: query
-                description: schema path
-                required: false
-                type: string
-              - name: hive_id
-                in: query
-                description: hive identifier (tablet id)
-                required: false
-                type: string
-              - name: enums
-                in: query
-                description: convert enums to strings
-                required: false
-                type: boolean
-              - name: ui64
-                in: query
-                description: return ui64 as number
-                required: false
-                type: boolean
-              - name: timeout
-                in: query
-                description: timeout in ms
-                required: false
-                type: integer
-            )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonNetInfo> {
-    static TString GetSummary() {
-        return "Network information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonNetInfo> {
-    static TString GetDescription() {
-        return "Returns network information";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_nodeinfo.h b/ydb/core/viewer/viewer_nodeinfo.h
similarity index 70%
rename from ydb/core/viewer/json_nodeinfo.h
rename to ydb/core/viewer/viewer_nodeinfo.h
index ac1dbb04878d..5165a1c96442 100644
--- a/ydb/core/viewer/json_nodeinfo.h
+++ b/ydb/core/viewer/viewer_nodeinfo.h
@@ -1,14 +1,7 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include "wb_merge.h"
 #include "json_wb_req.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 template <>
 struct TWhiteboardInfo<NKikimrWhiteboard::TEvNodeStateResponse> {
@@ -44,19 +37,4 @@ struct TWhiteboardInfo<NKikimrWhiteboard::TEvNodeStateResponse> {
 
 using TJsonNodeInfo = TJsonWhiteboardRequest<TEvWhiteboard::TEvNodeStateRequest, TEvWhiteboard::TEvNodeStateResponse>;
 
-template <>
-struct TJsonRequestSummary<TJsonNodeInfo> {
-    static TString GetSummary() {
-        return "Interconnect information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonNodeInfo> {
-    static TString GetDescription() {
-        return "Returns information about node connections";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_nodelist.h b/ydb/core/viewer/viewer_nodelist.h
similarity index 70%
rename from ydb/core/viewer/json_nodelist.h
rename to ydb/core/viewer/viewer_nodelist.h
index d1d3310f616e..d3b2963a1f4a 100644
--- a/ydb/core/viewer/json_nodelist.h
+++ b/ydb/core/viewer/viewer_nodelist.h
@@ -1,14 +1,11 @@
 #pragma once
+#include "json_handlers.h"
+#include "viewer.h"
+#include <library/cpp/json/json_writer.h>
 #include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
 #include <ydb/library/actors/interconnect/interconnect.h>
-#include <library/cpp/json/json_writer.h>
-#include <ydb/library/services/services.pb.h>
-#include "viewer.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -81,43 +78,37 @@ class TJsonNodeList : public TActorBootstrapped<TJsonNodeList> {
     void Timeout(const TActorContext &ctx) {
         ReplyAndDie(ctx);
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonNodeList> {
-    static YAML::Node GetSchema() {
-        return YAML::Load(R"___(
-            type: array
-            title: TEvNodeListResponse
-            items:
-                type: object
-                title: TNodeInfo
-                properties:
-                    Id:
-                        type: integer
-                    Host:
-                        type: string
-                    Address:
-                        type: string
-                    Port:
-                        type: integer
-            )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonNodeList> {
-    static TString GetSummary() {
-        return "Nodes list";
-    }
-};
 
-template <>
-struct TJsonRequestDescription<TJsonNodeList> {
-    static TString GetDescription() {
-        return "Returns list of nodes";
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
+            get:
+                tags:
+                - viewer
+                summary: Nodes list
+                description: Returns list of nodes
+                responses:
+                    200:
+                        description: Successful response
+                        content:
+                            application/json:
+                                schema:
+                                    type: array
+                                    title: TEvNodeListResponse
+                                    items:
+                                        type: object
+                                        title: TNodeInfo
+                                        properties:
+                                            Id:
+                                                type: integer
+                                            Host:
+                                                type: string
+                                            Address:
+                                                type: string
+                                            Port:
+                                                type: integer
+        )___");
+        return node;
     }
 };
 
 }
-}
diff --git a/ydb/core/viewer/json_nodes.h b/ydb/core/viewer/viewer_nodes.h
similarity index 91%
rename from ydb/core/viewer/json_nodes.h
rename to ydb/core/viewer/viewer_nodes.h
index e327d79d990c..3d305dd103e2 100644
--- a/ydb/core/viewer/json_nodes.h
+++ b/ydb/core/viewer/viewer_nodes.h
@@ -1,24 +1,16 @@
 #pragma once
-#include <unordered_map>
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/protos/node_whiteboard.pb.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
+#include "json_handlers.h"
+#include "json_pipe_req.h"
+#include "log.h"
 #include "viewer.h"
 #include "viewer_helper.h"
-#include "json_pipe_req.h"
-#include "json_sysinfo.h"
-#include "json_pdiskinfo.h"
+#include "viewer_tabletinfo.h"
+#include "wb_group.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
-using ::google::protobuf::FieldDescriptor;
 
 class TJsonNodes : public TViewerPipeClient {
     using TThis = TJsonNodes;
@@ -709,8 +701,8 @@ class TJsonNodes : public TViewerPipeClient {
         return 0;
     }
 
-    static uint32 GetMissing(const NKikimrViewer::TNodeInfo& nodeInfo) {
-        uint32 missing = 0;
+    static ui32 GetMissing(const NKikimrViewer::TNodeInfo& nodeInfo) {
+        ui32 missing = 0;
         for (const auto& pDisk : nodeInfo.GetPDisks()) {
             if (pDisk.state() != NKikimrBlobStorage::TPDiskState::Normal) {
                 missing++;
@@ -924,106 +916,87 @@ class TJsonNodes : public TViewerPipeClient {
     void HandleTimeout() {
         ReplyAndPassAway();
     }
-};
 
-template <>
-struct TJsonRequestSchema<TJsonNodes> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TNodesInfo>();
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Nodes info",
+            .Description = "Information about nodes",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as numbers",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "path to schema object",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "with",
+            .Description = "filter nodes by missing disks or space",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "type",
+            .Description = "nodes type to get (static,dynamic,any)",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "storage",
+            .Description = "return storage info",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "tablets",
+            .Description = "return tablets info",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "sort",
+            .Description = "sort by (NodeId,Host,DC,Rack,Version,Uptime,Memory,CPU,LoadAverage,Missing)",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "offset",
+            .Description = "skip N nodes",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "limit",
+            .Description = "limit to N nodes",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "uptime",
+            .Description = "return only nodes with less uptime in sec.",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "problems_only",
+            .Description = "return only problem nodes",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "filter",
+            .Description = "filter nodes by id or host",
+            .Type = "string",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TNodesInfo>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestParameters<TJsonNodes> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-              - name: enums
-                in: query
-                description: convert enums to strings
-                required: false
-                type: boolean
-              - name: ui64
-                in: query
-                description: return ui64 as numbers
-                required: false
-                type: boolean
-              - name: path
-                in: query
-                description: path to schema object
-                required: false
-                type: string
-              - name: with
-                in: query
-                description: filter nodes by missing disks or space
-                required: false
-                type: string
-              - name: type
-                in: query
-                description: nodes type to get (static,dynamic,any)
-                required: false
-                type: string
-              - name: storage
-                in: query
-                description: return storage info
-                required: false
-                type: boolean
-              - name: tablets
-                in: query
-                description: return tablets info
-                required: false
-                type: boolean
-              - name: sort
-                in: query
-                description: sort by (NodeId,Host,DC,Rack,Version,Uptime,Memory,CPU,LoadAverage,Missing)
-                required: false
-                type: string
-              - name: offset
-                in: query
-                description: skip N nodes
-                required: false
-                type: integer
-              - name: limit
-                in: query
-                description: limit to N nodes
-                required: false
-                type: integer
-              - name: timeout
-                in: query
-                description: timeout in ms
-                required: false
-                type: integer
-              - name: uptime
-                in: query
-                description: return only nodes with less uptime in sec.
-                required: false
-                type: integer
-              - name: problems_only
-                in: query
-                description: return only problem nodes
-                required: false
-                type: boolean
-              - name: filter
-                in: query
-                description: filter nodes by id or host
-                required: false
-                type: string
-        )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonNodes> {
-    static TString GetSummary() {
-        return "Nodes info";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonNodes> {
-    static TString GetDescription() {
-        return "Information about nodes";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_pdiskinfo.h b/ydb/core/viewer/viewer_pdiskinfo.h
similarity index 69%
rename from ydb/core/viewer/json_pdiskinfo.h
rename to ydb/core/viewer/viewer_pdiskinfo.h
index 5a2ff46edc2f..7c85393e667b 100644
--- a/ydb/core/viewer/json_pdiskinfo.h
+++ b/ydb/core/viewer/viewer_pdiskinfo.h
@@ -1,13 +1,7 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
 #include "json_wb_req.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 template <>
 struct TWhiteboardInfo<NKikimrWhiteboard::TEvPDiskStateResponse> {
@@ -41,19 +35,4 @@ struct TWhiteboardInfo<NKikimrWhiteboard::TEvPDiskStateResponse> {
 
 using TJsonPDiskInfo = TJsonWhiteboardRequest<TEvWhiteboard::TEvPDiskStateRequest, TEvWhiteboard::TEvPDiskStateResponse>;
 
-template <>
-struct TJsonRequestSummary<TJsonPDiskInfo> {
-    static TString GetSummary() {
-        return "PDisk information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonPDiskInfo> {
-    static TString GetDescription() {
-        return "Returns PDisk information";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_pqconsumerinfo.h b/ydb/core/viewer/viewer_pqconsumerinfo.h
similarity index 65%
rename from ydb/core/viewer/json_pqconsumerinfo.h
rename to ydb/core/viewer/viewer_pqconsumerinfo.h
index 0071ec99e8bd..88cc9d305f1c 100644
--- a/ydb/core/viewer/json_pqconsumerinfo.h
+++ b/ydb/core/viewer/viewer_pqconsumerinfo.h
@@ -1,20 +1,14 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/persqueue/events/global.h>
+#include "json_handlers.h"
+#include "viewer.h"
 #include <ydb/core/client/server/msgbus_server_persqueue.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
+#include <ydb/library/actors/core/actor_bootstrapped.h>
 #include <ydb/library/persqueue/topic_parser/topic_parser.h>
-#include "viewer.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
-
 class TJsonPQConsumerInfo : public TActorBootstrapped<TJsonPQConsumerInfo> {
     using TBase = TActorBootstrapped<TJsonPQConsumerInfo>;
     IViewer* Viewer;
@@ -115,76 +109,54 @@ class TJsonPQConsumerInfo : public TActorBootstrapped<TJsonPQConsumerInfo> {
         ctx.Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         Die(ctx);
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonPQConsumerInfo> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrClient::TPersQueueMetaResponse>();
-    }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonPQConsumerInfo> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: topic
-              in: query
-              description: topic name
-              required: true
-              type: string
-            - name: dc
-              in: query
-              description: dc name (required with version >= 3)
-              required: false
-              type: string
-              default: ""
-            - name: version
-              in: query
-              description: query version
-              required: false
-              type: integer
-              default: 0
-            - name: client
-              in: query
-              description: client name
-              required: true
-              type: string
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-              default: false
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-              default: false
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-              default: 10000
-            )___");
-    }
-};
 
-template <>
-struct TJsonRequestSummary<TJsonPQConsumerInfo> {
-    static TString GetSummary() {
-        return "Consumer-topic metrics";
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Consumer-topic metrics",
+            .Description = "Returns consumer-topic metrics",
+        });
+        yaml.AddParameter({
+            .Name = "topic",
+            .Description = "topic name",
+            .Type = "string",
+            .Required = true,
+        });
+        yaml.AddParameter({
+            .Name = "dc",
+            .Description = "dc name (required with version >= 3)",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "version",
+            .Description = "query version",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "client",
+            .Description = "client name",
+            .Type = "string",
+            .Required = true,
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrClient::TPersQueueMetaResponse>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestDescription<TJsonPQConsumerInfo> {
-    static TString GetDescription() {
-        return "Returns consumer-topic metrics";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/viewer_probes.cpp b/ydb/core/viewer/viewer_probes.cpp
deleted file mode 100644
index 616d63e91e39..000000000000
--- a/ydb/core/viewer/viewer_probes.cpp
+++ /dev/null
@@ -1,2 +0,0 @@
-#include "viewer_probes.h"
-LWTRACE_DEFINE_PROVIDER(VIEWER_PROVIDER)
diff --git a/ydb/core/viewer/viewer_probes.h b/ydb/core/viewer/viewer_probes.h
deleted file mode 100644
index 3ce88fc06f1a..000000000000
--- a/ydb/core/viewer/viewer_probes.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#pragma once
-#include <library/cpp/lwtrace/all.h>
-
-#define VIEWER_PROVIDER(PROBE, EVENT, GROUPS, TYPES, NAMES) \
-    PROBE(ViewerClusterHandler, \
-        GROUPS(), \
-        TYPES(ui32, bool, bool, \
-            double, double, double, double, \
-            double, double, double, double, \
-            double, double), \
-        NAMES("nodeId", "tabletsParam", "requestTimeout", \
-            "startTime", "totalDurationMs", \
-            "getListTenantsResponseDurationMs","getNodesInfoDurationMs", \
-            "collectingDurationMs", "mergeBSGroupsDurationMs", \
-            "mergeVDisksDurationMs", "mergePDisksDurationMs", \
-            "mergeTabletsDurationMs", "responseBuildingDurationMs")) \
-/**/
-LWTRACE_DECLARE_PROVIDER(VIEWER_PROVIDER)
diff --git a/ydb/core/viewer/json_query.h b/ydb/core/viewer/viewer_query.h
similarity index 84%
rename from ydb/core/viewer/json_query.h
rename to ydb/core/viewer/viewer_query.h
index 2fa05b20225d..de09c55d4320 100644
--- a/ydb/core/viewer/json_query.h
+++ b/ydb/core/viewer/viewer_query.h
@@ -1,29 +1,21 @@
 #pragma once
-#include "viewer.h"
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <library/cpp/json/json_value.h>
-#include <library/cpp/json/json_reader.h>
-#include <library/cpp/protobuf/json/proto2json.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
+#include "json_handlers.h"
+#include "json_pipe_req.h"
+#include "log.h"
 #include <ydb/core/grpc_services/rpc_kqp_base.h>
 #include <ydb/core/kqp/common/kqp.h>
 #include <ydb/core/kqp/executer_actor/kqp_executer.h>
-#include <ydb/core/viewer/json/json.h>
 #include <ydb/public/lib/json_value/ydb_json_value.h>
 #include <ydb/public/sdk/cpp/client/ydb_result/result.h>
-#include "json_pipe_req.h"
-#include "viewer_request.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NMonitoring;
-using ::google::protobuf::FieldDescriptor;
 using namespace NNodeWhiteboard;
 
+bool IsPostContent(const NMon::TEvHttpInfo::TPtr& event);
+
 class TJsonQuery : public TViewerPipeClient {
     using TThis = TJsonQuery;
     using TBase = TViewerPipeClient;
@@ -611,133 +603,132 @@ class TJsonQuery : public TViewerPipeClient {
             NProtobufJson::Proto2Json(response.GetQueryStats(), jsonResponse["stats"]);
         }
     }
-};
 
-template <>
-YAML::Node TJsonRequestSwagger<TJsonQuery>::GetSwagger() {
-    YAML::Node node = YAML::Load(R"___(
+public:
+    static YAML::Node GetSwagger() {
+        YAML::Node node = YAML::Load(R"___(
         post:
-          tags:
-          - viewer
-          summary: Executes SQL query
-          description: Executes SQL query
-          parameters:
-          - name: action
-            in: query
-            type: string
-            enum: [execute-scan, execute-script, execute-query, execute-data, explain-ast, explain-scan, explain-script, explain-query, explain-data, cancel-query]
-            required: true
-            description: >
-              execute method:
-               * `execute-query` - execute query (QueryService)
-               * `execute-data` - execute data query (DataQuery)
-               * `execute-scan` - execute scan query (ScanQuery)
-               * `execute-script` - execute script query (ScriptingService)
-               * `explain-query` - explain query (QueryService)
-               * `explain-data` - explain data query (DataQuery)
-               * `explain-scan` - explain scan query (ScanQuery)
-               * `explain-script` - explain script query (ScriptingService)
-               * `cancel-query` - cancel query (using query_id)
-          - name: database
-            in: query
-            description: database name
-            type: string
-            required: false
-          - name: query
-            in: query
-            description: SQL query text
-            type: string
-            required: false
-          - name: query_id
-            in: query
-            description: unique query identifier (uuid) - use the same id to cancel query
-            required: false
-          - name: syntax
-            in: query
-            description: >
-              query syntax:
-               * `yql_v1` - YQL v1 (default)
-               * `pg` - PostgreSQL compatible
-            type: string
-            enum: [yql_v1, pg]
-            required: false
-          - name: schema
-            in: query
-            description: >
-              result format schema:
-               * `classic`
-               * `modern`
-               * `multi`
-               * `ydb`
-            type: string
-            enum: [classic, modern, ydb, multi]
-            required: false
-          - name: stats
-            in: query
-            description: >
-              return stats:
-               * `profile`
-               * `full`
-            type: string
-            enum: [profile, full]
-            required: false
-          - name: transaction_mode
-            in: query
-            description: >
-              transaction mode:
-               * `serializable-read-write`
-               * `online-read-only`
-               * `stale-read-only`
-               * `snapshot-read-only`
-            type: string
-            enum: [serializable-read-write, online-read-only, stale-read-only, snapshot-read-only]
-            required: false
-          - name: direct
-            in: query
-            description: force processing query on current node
-            type: boolean
-            required: false
-          - name: base64
-            in: query
-            description: return strings using base64 encoding
-            type: string
-            required: false
-          - name: timeout
-            in: query
-            description: timeout in ms
-            type: integer
-            required: false
-          - name: ui64
-            in: query
-            description: return ui64 as number to avoid 56-bit js rounding
-            type: boolean
-            required: false
-          requestBody:
+            tags:
+              - viewer
+            summary: Executes SQL query
             description: Executes SQL query
-            required: false
-            content:
-              application/json:
-                schema:
-                  type: object
-                  description: the same properties as in query parameters
-          responses:
-            200:
-              description: OK
-              content:
-                application/json:
-                  schema:
-                    type: object
-                    description: format depends on schema parameter
-            400:
-              description: Bad Request
-            403:
-              description: Forbidden
-            504:
-              description: Gateway Timeout
-        )___");
-    return node;
-}
-
+            parameters:
+              - name: action
+                in: query
+                type: string
+                enum: [execute-scan, execute-script, execute-query, execute-data, explain-ast, explain-scan, explain-script, explain-query, explain-data, cancel-query]
+                required: true
+                description: >
+                    execute method:
+                      * `execute-query` - execute query (QueryService)
+                      * `execute-data` - execute data query (DataQuery)
+                      * `execute-scan` - execute scan query (ScanQuery)
+                      * `execute-script` - execute script query (ScriptingService)
+                      * `explain-query` - explain query (QueryService)
+                      * `explain-data` - explain data query (DataQuery)
+                      * `explain-scan` - explain scan query (ScanQuery)
+                      * `explain-script` - explain script query (ScriptingService)
+                      * `cancel-query` - cancel query (using query_id)
+              - name: database
+                in: query
+                description: database name
+                type: string
+                required: false
+              - name: query
+                in: query
+                description: SQL query text
+                type: string
+                required: false
+              - name: query_id
+                in: query
+                description: unique query identifier (uuid) - use the same id to cancel query
+                required: false
+              - name: syntax
+                in: query
+                description: >
+                    query syntax:
+                      * `yql_v1` - YQL v1 (default)
+                      * `pg` - PostgreSQL compatible
+                type: string
+                enum: [yql_v1, pg]
+                required: false
+              - name: schema
+                in: query
+                description: >
+                    result format schema:
+                      * `classic`
+                      * `modern`
+                      * `multi`
+                      * `ydb`
+                type: string
+                enum: [classic, modern, ydb, multi]
+                required: false
+              - name: stats
+                in: query
+                description: >
+                    return stats:
+                      * `profile`
+                      * `full`
+                type: string
+                enum: [profile, full]
+                required: false
+              - name: transaction_mode
+                in: query
+                description: >
+                    transaction mode:
+                      * `serializable-read-write`
+                      * `online-read-only`
+                      * `stale-read-only`
+                      * `snapshot-read-only`
+                type: string
+                enum: [serializable-read-write, online-read-only, stale-read-only, snapshot-read-only]
+                required: false
+              - name: direct
+                in: query
+                description: force processing query on current node
+                type: boolean
+                required: false
+              - name: base64
+                in: query
+                description: return strings using base64 encoding
+                type: string
+                required: false
+              - name: timeout
+                in: query
+                description: timeout in ms
+                type: integer
+                required: false
+              - name: ui64
+                in: query
+                description: return ui64 as number to avoid 56-bit js rounding
+                type: boolean
+                required: false
+            requestBody:
+                description: Executes SQL query
+                required: false
+                content:
+                    application/json:
+                        schema:
+                            type: object
+                            description: the same properties as in query parameters
+            responses:
+                200:
+                    description: OK
+                    content:
+                        application/json:
+                            schema:
+                                type: object
+                                description: format depends on schema parameter
+                400:
+                    description: Bad Request
+                403:
+                    description: Forbidden
+                504:
+                    description: Gateway Timeout
+            )___");
+        return node;
+    }
+};
 
 }
-}
+
diff --git a/ydb/core/viewer/json_query_old.h b/ydb/core/viewer/viewer_query_old.h
similarity index 98%
rename from ydb/core/viewer/json_query_old.h
rename to ydb/core/viewer/viewer_query_old.h
index 6ef43bacc234..9b130e9be793 100644
--- a/ydb/core/viewer/json_query_old.h
+++ b/ydb/core/viewer/viewer_query_old.h
@@ -1,23 +1,14 @@
 #pragma once
+#include "json_pipe_req.h"
+#include "log.h"
 #include "viewer.h"
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <library/cpp/json/json_value.h>
-#include <library/cpp/json/json_reader.h>
-#include <library/cpp/protobuf/json/proto2json.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/grpc_services/rpc_kqp_base.h>
+#include "viewer_request.h"
 #include <ydb/core/kqp/common/kqp.h>
 #include <ydb/core/kqp/executer_actor/kqp_executer.h>
-#include <ydb/core/viewer/json/json.h>
 #include <ydb/public/lib/json_value/ydb_json_value.h>
 #include <ydb/public/sdk/cpp/client/ydb_result/result.h>
-#include "json_pipe_req.h"
-#include "viewer_request.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NMonitoring;
@@ -627,9 +618,6 @@ class TJsonQueryOld : public TViewerPipeClient {
             NProtobufJson::Proto2Json(response.GetQueryStats(), jsonResponse["stats"]);
         }
     }
-
 };
 
-
-}
 }
diff --git a/ydb/core/viewer/json_render.h b/ydb/core/viewer/viewer_render.h
similarity index 81%
rename from ydb/core/viewer/json_render.h
rename to ydb/core/viewer/viewer_render.h
index 1e84eacac818..71ffc7f6e3ae 100644
--- a/ydb/core/viewer/json_render.h
+++ b/ydb/core/viewer/viewer_render.h
@@ -1,16 +1,12 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/graph/api/service.h>
-#include <ydb/core/graph/api/events.h>
-#include <library/cpp/json/json_writer.h>
+#include "json_handlers.h"
 #include "json_pipe_req.h"
-#include "viewer_request.h"
-#include "viewer.h"
 #include "log.h"
+#include "viewer_request.h"
+#include <ydb/core/graph/api/events.h>
+#include <ydb/core/graph/api/service.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NMonitoring;
@@ -18,8 +14,6 @@ using namespace NMonitoring;
 class TJsonRender : public TViewerPipeClient {
     using TThis = TJsonRender;
     using TBase = TViewerPipeClient;
-    IViewer* Viewer;
-    NMon::TEvHttpInfo::TPtr Event;
     TEvViewer::TEvViewerRequest::TPtr ViewerRequest;
     ui32 Timeout = 0;
     std::vector<TString> Metrics;
@@ -31,9 +25,8 @@ class TJsonRender : public TViewerPipeClient {
     bool Direct = false;
     bool MadeProxyRequest = false;
 public:
-    TJsonRender(IViewer* viewer, NMon::TEvHttpInfo::TPtr &ev)
-        : Viewer(viewer)
-        , Event(ev)
+    TJsonRender(IViewer* viewer, NMon::TEvHttpInfo::TPtr& ev)
+        : TViewerPipeClient(viewer, ev)
     {
         const auto& params(Event->Get()->Request.GetParams());
 
@@ -196,22 +189,19 @@ class TJsonRender : public TViewerPipeClient {
             if (response.GetError()) {
                 json["status"] = "error";
                 json["error"] = response.GetError();
-                ReplyAndPassAway(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)));
-                return;
+                return ReplyAndPassAway(GetHTTPOKJSON(json));
             }
             if (response.DataSize() != Metrics.size()) {
                 json["status"] = "error";
                 json["error"] = "Invalid data size received";
-                ReplyAndPassAway(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)));
-                return;
+                return ReplyAndPassAway(GetHTTPOKJSON(json));
             }
             for (size_t nMetric = 0; nMetric < response.DataSize(); ++nMetric) {
                 const auto& protoMetric(response.GetData(nMetric));
                 if (response.TimeSize() != protoMetric.ValuesSize()) {
                     json["status"] = "error";
                     json["error"] = "Invalid value size received";
-                    ReplyAndPassAway(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)));
-                    return;
+                    return ReplyAndPassAway(GetHTTPOKJSON(json));
                 }
             }
             { // graphite
@@ -237,7 +227,7 @@ class TJsonRender : public TViewerPipeClient {
                 }
             }
 
-            ReplyAndPassAway(Viewer->GetHTTPOKJSON(Event->Get(), NJson::WriteJson(json, false)));
+            ReplyAndPassAway(GetHTTPOKJSON(json));
         } else {
             TEvViewer::TEvViewerResponse* viewerResponse = new TEvViewer::TEvViewerResponse();
             viewerResponse->Record.MutableRenderResponse()->CopyFrom(response);
@@ -280,64 +270,52 @@ class TJsonRender : public TViewerPipeClient {
 
     void ReplyAndPassAway() override {
     }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonRender> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: target
-              in: query
-              description: metrics comma delimited
-              required: true
-              type: string
-            - name: from
-              in: query
-              description: time in seconds
-              required: false
-              type: integer
-            - name: database
-              in: query
-              description: database name
-              required: false
-              type: string
-            - name: direct
-              in: query
-              description: force processing query on current node
-              required: false
-              type: boolean
-            - name: until
-              in: query
-              description: time in seconds
-              required: false
-              type: integer
-            - name: maxDataPoints
-              in: query
-              description: maximum number of data points
-              required: false
-              type: integer
-            - name: format
-              in: query
-              description: response format
-              required: false
-              type: string
-            )___");
-    }
-};
 
-template <>
-struct TJsonRequestSummary<TJsonRender> {
-    static TString GetSummary() {
-        return "Graph data";
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Graph data",
+            .Description = "Returns graph data in graphite format",
+        });
+        yaml.AddParameter({
+            .Name = "target",
+            .Description = "metrics comma delimited",
+            .Type = "string",
+            .Required = true,
+        });
+        yaml.AddParameter({
+            .Name = "from",
+            .Description = "time in seconds",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "database",
+            .Description = "database name",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "direct",
+            .Description = "force processing query on current node",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "until",
+            .Description = "time in seconds",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "maxDataPoints",
+            .Description = "maximum number of data points",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "format",
+            .Description = "response format",
+            .Type = "string",
+        });
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestDescription<TJsonRender> {
-    static TString GetDescription() {
-        return "Returns graph data in graphite format";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/viewer_request.cpp b/ydb/core/viewer/viewer_request.cpp
index 32963a848c2f..6941b5321e86 100644
--- a/ydb/core/viewer/viewer_request.cpp
+++ b/ydb/core/viewer/viewer_request.cpp
@@ -1,16 +1,12 @@
-#include <ydb/core/blobstorage/base/blobstorage_events.h>
-
 #include "viewer_request.h"
+#include "viewer_autocomplete.h"
+#include "viewer_query_old.h"
+#include "viewer_render.h"
+#include "viewer_sysinfo.h"
+#include "viewer_tabletinfo.h"
 #include "wb_req.h"
 
-#include "json_tabletinfo.h"
-#include "json_sysinfo.h"
-#include "json_query_old.h"
-#include "json_render.h"
-#include "json_autocomplete.h"
-
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
@@ -107,4 +103,3 @@ bool IsPostContent(const NMon::TEvHttpInfo::TPtr& event) {
 }
 
 }
-}
diff --git a/ydb/core/viewer/viewer_request.h b/ydb/core/viewer/viewer_request.h
index 6516dbb59d18..20fb126761fb 100644
--- a/ydb/core/viewer/viewer_request.h
+++ b/ydb/core/viewer/viewer_request.h
@@ -1,9 +1,7 @@
 #pragma once
-
 #include "viewer.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -41,4 +39,3 @@ IActor* CreateViewerRequestHandler(TEvViewer::TEvViewerRequest::TPtr& request);
 bool IsPostContent(const NMon::TEvHttpInfo::TPtr& event);
 
 }
-}
diff --git a/ydb/core/viewer/json_storage.h b/ydb/core/viewer/viewer_storage.h
similarity index 85%
rename from ydb/core/viewer/json_storage.h
rename to ydb/core/viewer/viewer_storage.h
index fba5047a69e0..dc23e974e84c 100644
--- a/ydb/core/viewer/json_storage.h
+++ b/ydb/core/viewer/viewer_storage.h
@@ -1,8 +1,10 @@
 #pragma once
+#include "json_handlers.h"
 #include "json_storage_base.h"
+#include "viewer_pdiskinfo.h"
+#include "viewer_vdiskinfo.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
@@ -478,124 +480,105 @@ class TJsonStorage : public TJsonStorageBase {
         Send(Initiator, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), std::move(json.Str())), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         PassAway();
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonStorage> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TStorageInfo>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonStorage> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-              - name: enums
-                in: query
-                description: convert enums to strings
-                required: false
-                type: boolean
-              - name: ui64
-                in: query
-                description: return ui64 as number
-                required: false
-                type: boolean
-              - name: tenant
-                in: query
-                description: tenant name
-                required: false
-                type: string
-              - name: pool
-                in: query
-                description: storage pool name
-                required: false
-                type: string
-              - name: node_id
-                in: query
-                description: node id
-                required: false
-                type: integer
-              - name: pdisk_id
-                in: query
-                description: pdisk id
-                required: false
-                type: integer
-              - name: group_id
-                in: query
-                description: group id
-                required: false
-                type: integer
-              - name: need_groups
-                in: query
-                description: return groups information
-                required: false
-                type: boolean
-                default: true
-              - name: need_disks
-                in: query
-                description: return disks information
-                required: false
-                type: boolean
-                default: true
-              - name: with
-                in: query
-                description: filter groups by missing or space
-                required: false
-                type: string
-              - name: version
-                in: query
-                description: query version (v1, v2)
-                required: false
-                type: string
-              - name: usage_pace
-                in: query
-                description: bucket size as a percentage
-                required: false
-                type: integer
-                default: 5
-              - name: usage_buckets
-                in: query
-                description: filter groups by usage buckets
-                required: false
-                type: integer
-              - name: sort
-                in: query
-                description: sort by (PoolName,Kind,MediaType,Erasure,Degraded,Usage,GroupId,Used,Limit,Read,Write)
-                required: false
-                type: string
-              - name: offset
-                in: query
-                description: skip N nodes
-                required: false
-                type: integer
-              - name: limit
-                in: query
-                description: limit to N nodes
-                required: false
-                type: integer
-              - name: timeout
-                in: query
-                description: timeout in ms
-                required: false
-                type: integer
-            )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Storage information",
+            .Description = "Returns information about storage"
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean"
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean"
+        });
+        yaml.AddParameter({
+            .Name = "tenant",
+            .Description = "tenant name",
+            .Type = "string"
+        });
+        yaml.AddParameter({
+            .Name = "pool",
+            .Description = "storage pool name",
+            .Type = "string"
+        });
+        yaml.AddParameter({
+            .Name = "node_id",
+            .Description = "node id",
+            .Type = "integer"
+        });
+        yaml.AddParameter({
+            .Name = "pdisk_id",
+            .Description = "pdisk id",
+            .Type = "integer"
+        });
+        yaml.AddParameter({
+            .Name = "group_id",
+            .Description = "group id",
+            .Type = "integer"
+        });
+        yaml.AddParameter({
+            .Name = "need_groups",
+            .Description = "return groups information",
+            .Type = "boolean",
+            .Default = "true"
+        });
+        yaml.AddParameter({
+            .Name = "need_disks",
+            .Description = "return disks information",
+            .Type = "boolean",
+            .Default = "true"
+        });
+        yaml.AddParameter({
+            .Name = "with",
+            .Description = "filter groups by missing or space",
+            .Type = "string"
+        });
+        yaml.AddParameter({
+            .Name = "version",
+            .Description = "query version (v1, v2)",
+            .Type = "string"
+        });
+        yaml.AddParameter({
+            .Name = "usage_pace",
+            .Description = "bucket size as a percentage",
+            .Type = "integer",
+            .Default = "5"
+        });
+        yaml.AddParameter({
+            .Name = "usage_buckets",
+            .Description = "filter groups by usage buckets",
+            .Type = "integer"
+        });
+        yaml.AddParameter({
+            .Name = "sort",
+            .Description = "sort by (PoolName,Kind,MediaType,Erasure,Degraded,Usage,GroupId,Used,Limit,Read,Write)",
+            .Type = "string"
+        });
+        yaml.AddParameter({
+            .Name = "offset",
+            .Description = "skip N nodes",
+            .Type = "integer"
+        });
+        yaml.AddParameter({
+            .Name = "limit",
+            .Description = "limit to N nodes",
+            .Type = "integer"
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer"
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TStorageInfo>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonStorage> {
-    static TString GetSummary() {
-        return "Storage information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonStorage> {
-    static TString GetDescription() {
-        return "Returns information about storage";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_storage_usage.h b/ydb/core/viewer/viewer_storage_usage.h
similarity index 59%
rename from ydb/core/viewer/json_storage_usage.h
rename to ydb/core/viewer/viewer_storage_usage.h
index e759a72c3ecf..e1bad4fb2e1c 100644
--- a/ydb/core/viewer/json_storage_usage.h
+++ b/ydb/core/viewer/viewer_storage_usage.h
@@ -1,14 +1,14 @@
 #pragma once
+#include "json_handlers.h"
 #include "json_storage_base.h"
+#include "viewer_pdiskinfo.h"
+#include "viewer_vdiskinfo.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
 
-using ::google::protobuf::FieldDescriptor;
-
 class TJsonStorageUsage : public TJsonStorageBase {
     using TBase = TJsonStorageBase;
     using TThis = TJsonStorageUsage;
@@ -75,72 +75,53 @@ class TJsonStorageUsage : public TJsonStorageBase {
         Send(Initiator, new NMon::TEvHttpInfoRes(Viewer->GetHTTPOKJSON(Event->Get(), std::move(json.Str())), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         PassAway();
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonStorageUsage> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TStorageUsageStats>();
-    }
-};
-
-template <>
-struct TJsonRequestParameters<TJsonStorageUsage> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-              - name: enums
-                in: query
-                description: convert enums to strings
-                type: boolean
-                required: false
-              - name: ui64
-                in: query
-                description: return ui64 as number
-                type: boolean
-                required: false
-              - name: tenant
-                in: query
-                description: tenant name
-                type: string
-                required: false
-              - name: pool
-                in: query
-                description: storage pool name
-                type: string
-                required: false
-              - name: node_id
-                in: query
-                description: node id
-                type: integer
-                required: false
-              - name: pace
-                in: query
-                description: bucket size as a percentage
-                type: integer
-                required: false
-                default: 5
-              - name: timeout
-                in: query
-                description: timeout in ms
-                type: integer
-                required: false
-                )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonStorageUsage> {
-    static TString GetSummary() {
-        return "Storage groups statistics";
-    }
-};
 
-template <>
-struct TJsonRequestDescription<TJsonStorageUsage> {
-    static TString GetDescription() {
-        return "Returns the distribution of groups by usage";
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Storage groups statistics",
+            .Description = "Returns the distribution of groups by usage",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "tenant",
+            .Description = "tenant name",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "pool",
+            .Description = "storage pool name",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "node_id",
+            .Description = "node id",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "pace",
+            .Description = "bucket size as a percentage",
+            .Type = "integer",
+            .Default = "5",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TStorageUsageStats>());
+        return yaml;
     }
 };
 
 }
-}
diff --git a/ydb/core/viewer/json_sysinfo.h b/ydb/core/viewer/viewer_sysinfo.h
similarity index 78%
rename from ydb/core/viewer/json_sysinfo.h
rename to ydb/core/viewer/viewer_sysinfo.h
index 922f9566b917..f35c3a11fbc2 100644
--- a/ydb/core/viewer/json_sysinfo.h
+++ b/ydb/core/viewer/viewer_sysinfo.h
@@ -1,13 +1,7 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
 #include "json_wb_req.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 template <>
 class TWhiteboardMerger<TEvWhiteboard::TEvSystemStateResponse> {
@@ -55,19 +49,4 @@ struct TWhiteboardInfo<NKikimrWhiteboard::TEvSystemStateResponse> {
 
 using TJsonSysInfo = TJsonWhiteboardRequest<TEvWhiteboard::TEvSystemStateRequest, TEvWhiteboard::TEvSystemStateResponse>;
 
-template <>
-struct TJsonRequestSummary<TJsonSysInfo> {
-    static TString GetSummary() {
-        return "System information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonSysInfo> {
-    static TString GetDescription() {
-        return "Returns system information";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_tabletcounters.h b/ydb/core/viewer/viewer_tabletcounters.h
similarity index 78%
rename from ydb/core/viewer/json_tabletcounters.h
rename to ydb/core/viewer/viewer_tabletcounters.h
index 023552fdea3f..60b99eb49ee7 100644
--- a/ydb/core/viewer/json_tabletcounters.h
+++ b/ydb/core/viewer/viewer_tabletcounters.h
@@ -1,17 +1,13 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
+#include "json_handlers.h"
+#include "viewer.h"
+#include "wb_aggregate.h"
 #include <ydb/core/base/tablet.h>
 #include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
 #include <ydb/core/tx/schemeshard/schemeshard.h>
 #include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/json/json.h>
-#include "viewer.h"
-#include "wb_aggregate.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -165,66 +161,47 @@ class TJsonTabletCounters : public TActorBootstrapped<TJsonTabletCounters> {
         ctx.Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         Die(ctx);
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonTabletCounters> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<TEvTablet::TEvGetCountersResponse::ProtoRecordType>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonTabletCounters> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: path
-              in: query
-              description: schema path
-              required: false
-              type: string
-            - name: tablet_id
-              in: query
-              description: tablet identifier
-              required: false
-              type: integer
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: aggregate
-              in: query
-              description: aggregate tablet counters
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Tablet counters info",
+            .Description = "Returns information about tablet counters",
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "tablet_id",
+            .Description = "tablet identifier",
+            .Type = "integer",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "aggregate",
+            .Description = "aggregate tablet counters",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TEvTablet::TEvGetCountersResponse::ProtoRecordType>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonTabletCounters> {
-    static TString GetSummary() {
-        return "Tablet counters information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonTabletCounters> {
-    static TString GetDescription() {
-        return "Returns information about tablet counters";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_tabletinfo.h b/ydb/core/viewer/viewer_tabletinfo.h
similarity index 84%
rename from ydb/core/viewer/json_tabletinfo.h
rename to ydb/core/viewer/viewer_tabletinfo.h
index aac8fabe01a5..b61a757e98d4 100644
--- a/ydb/core/viewer/json_tabletinfo.h
+++ b/ydb/core/viewer/viewer_tabletinfo.h
@@ -1,21 +1,8 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/protos/node_whiteboard.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/util/wildcard.h>
-#include <ydb/core/scheme/scheme_tablecell.h>
-#include "json_pipe_req.h"
 #include "json_wb_req.h"
-#include <span>
+#include <ydb/core/util/wildcard.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 template<>
 struct TWhiteboardInfo<NKikimrWhiteboard::TEvTabletStateResponse> {
@@ -362,111 +349,6 @@ class TJsonTabletInfo : public TJsonWhiteboardRequest<TEvWhiteboard::TEvTabletSt
             cFunc(TEvents::TSystem::Wakeup, HandleTimeout);
         }
     }
-
-    void PassAway() override {
-        TBase::PassAway();
-    }
 };
 
-template <>
-struct TJsonRequestParameters<TJsonTabletInfo> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: node_id
-              in: query
-              description: node identifier
-              required: false
-              type: integer
-            - name: path
-              in: query
-              description: schema path
-              required: false
-              type: string
-            - name: merge
-              in: query
-              description: merge information from nodes
-              required: false
-              type: boolean
-            - name: group
-              in: query
-              description: group information by field
-              required: false
-              type: string
-            - name: all
-              in: query
-              description: return all possible key combinations (for enums only)
-              required: false
-              type: boolean
-            - name: filter
-              in: query
-              description: filter information by field
-              required: false
-              type: string
-            - name: alive
-              in: query
-              description: request from alive (connected) nodes only
-              required: false
-              type: boolean
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-            - name: retries
-              in: query
-              description: number of retries
-              required: false
-              type: integer
-            - name: retry_period
-              in: query
-              description: retry period in ms
-              required: false
-              type: integer
-              default: 500
-            - name: static
-              in: query
-              description: request from static nodes only
-              required: false
-              type: boolean
-            - name: since
-              in: query
-              description: filter by update time
-              required: false
-              type: string
-            )___");
-    }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonTabletInfo> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrWhiteboard::TEvTabletStateResponse>();
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonTabletInfo> {
-    static TString GetSummary() {
-        return "Tablet information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonTabletInfo> {
-    static TString GetDescription() {
-        return "Returns information about tablets";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_tenantinfo.h b/ydb/core/viewer/viewer_tenantinfo.h
similarity index 92%
rename from ydb/core/viewer/json_tenantinfo.h
rename to ydb/core/viewer/viewer_tenantinfo.h
index 7826103538c4..30789adce2d3 100644
--- a/ydb/core/viewer/json_tenantinfo.h
+++ b/ydb/core/viewer/viewer_tenantinfo.h
@@ -1,29 +1,19 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/core/base/subdomain.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/cms/console/console.h>
-#include <ydb/core/base/hive.h>
-#include <ydb/core/grpc_services/db_metadata_cache.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include <ydb/core/viewer/protos/viewer.pb.h>
-#include <ydb/core/viewer/json/json.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
-#include "wb_aggregate.h"
-#include "wb_merge.h"
 #include "log.h"
+#include "viewer.h"
 #include "viewer_request.h"
+#include "viewer_tabletinfo.h"
+#include "wb_aggregate.h"
+#include "wb_merge.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
+NKikimrViewer::EFlag GetViewerFlag(Ydb::Monitoring::StatusFlag::Status flag);
+
 class TJsonTenantInfo : public TViewerPipeClient {
     using TThis = TJsonTenantInfo;
     using TBase = TViewerPipeClient;
@@ -384,8 +374,7 @@ class TJsonTenantInfo : public TViewerPipeClient {
 
     void Handle(NNodeWhiteboard::TEvWhiteboard::TEvTabletStateResponse::TPtr& ev) {
         ui32 nodeId = ev.Get()->Cookie;
-        BLOG_TRACE("Received TEvTabletStateResponse from " << nodeId << " with "
-            << TWhiteboardInfo<NKikimrWhiteboard::TEvTabletStateResponse>::GetElementsCount(ev->Get()->Record) << " tablets");
+        BLOG_TRACE("Received TEvTabletStateResponse from " << nodeId);
         auto tenantId = NodeIdsToTenant[nodeId];
         WhiteboardTabletStateResponse[tenantId][nodeId] = std::move(ev->Get()->Record);
         RequestDone();
@@ -418,9 +407,7 @@ class TJsonTenantInfo : public TViewerPipeClient {
         auto tenantId = NodeIdsToTenant[nodeId];
         switch (ev->Get()->Record.GetResponseCase()) {
             case NKikimrViewer::TEvViewerResponse::kTabletResponse:
-                BLOG_TRACE("Received TEvViewerResponse from " << nodeId << " with "
-                    << TWhiteboardInfo<NKikimrWhiteboard::TEvTabletStateResponse>::GetElementsCount(ev->Get()->Record.GetTabletResponse())
-                    << " tablets");
+                BLOG_TRACE("Received TEvViewerResponse from " << nodeId);
                 OffloadMergedTabletStateResponse[tenantId] = std::move(ev->Get()->Record);
                 RequestDone();
                 break;
@@ -863,96 +850,77 @@ class TJsonTenantInfo : public TViewerPipeClient {
         Result.AddErrors("Timeout occurred");
         ReplyAndPassAway();
     }
-};
 
-template <>
-struct TJsonRequestSchema<TJsonTenantInfo> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TTenantInfo>();
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Tenant info (detailed)",
+            .Description = "Returns information about tenants",
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "user",
+            .Description = "tenant owner",
+            .Type = "string",
+        });
+        yaml.AddParameter({
+            .Name = "followers",
+            .Description = "return followers",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "metrics",
+            .Description = "return tablet metrics",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "tablets",
+            .Description = "return tablets",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "system_tablets",
+            .Description = "return system tablets",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "offload_merge",
+            .Description = "use offload merge",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "storage",
+            .Description = "return storage info",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "nodes",
+            .Description = "return nodes info",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NKikimrViewer::TTenantInfo>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestParameters<TJsonTenantInfo> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: path
-              in: query
-              description: schema path
-              required: false
-              type: string
-            - name: user
-              in: query
-              description: tenant owner
-              required: false
-              type: string
-            - name: followers
-              in: query
-              description: return followers
-              required: false
-              type: boolean
-            - name: metrics
-              in: query
-              description: return tablet metrics
-              required: false
-              type: boolean
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: tablets
-              in: query
-              description: return tablets
-              required: false
-              type: boolean
-            - name: system_tablets
-              in: query
-              description: return system tablets
-              required: false
-              type: boolean
-            - name: offload_merge
-              in: query
-              description: use offload merge
-              required: false
-              type: boolean
-            - name: storage
-              in: query
-              description: return storage info
-              required: false
-              type: boolean
-            - name: nodes
-              in: query
-              description: return nodes info
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-        )___");
-    }
-};
-
-template <>
-struct TJsonRequestSummary<TJsonTenantInfo> {
-    static TString GetSummary() {
-        return "\"Tenant info (detailed)\"";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonTenantInfo> {
-    static TString GetDescription() {
-        return "\"Returns information about tenants\"";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_tenants.h b/ydb/core/viewer/viewer_tenants.h
similarity index 67%
rename from ydb/core/viewer/json_tenants.h
rename to ydb/core/viewer/viewer_tenants.h
index 4397565566a5..d0c2baa1c637 100644
--- a/ydb/core/viewer/json_tenants.h
+++ b/ydb/core/viewer/viewer_tenants.h
@@ -1,17 +1,9 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/cms/console/console.h>
-#include <ydb/core/viewer/json/json.h>
-#include "viewer.h"
+#include "json_handlers.h"
 #include "json_pipe_req.h"
 #include "wb_aggregate.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -95,57 +87,38 @@ class TJsonTenants : public TViewerPipeClient {
         Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         PassAway();
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonTenants> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<NConsole::TEvConsole::TEvListTenantsResponse::ProtoRecordType>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonTenants> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: state
-              in: query
-              description: return tenant state
-              required: false
-              type: boolean
-              default: true
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-              )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Tenant info (brief)",
+            .Description = "Returns list of tenants",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "state",
+            .Description = "return tenant state",
+            .Type = "boolean",
+            .Default = "true",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<NConsole::TEvConsole::TEvListTenantsResponse::ProtoRecordType>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonTenants> {
-    static TString GetSummary() {
-        return "Tenant info (brief)";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonTenants> {
-    static TString GetDescription() {
-        return "Returns list of tenants";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_topicinfo.h b/ydb/core/viewer/viewer_topicinfo.h
similarity index 64%
rename from ydb/core/viewer/json_topicinfo.h
rename to ydb/core/viewer/viewer_topicinfo.h
index d5880859ff16..9172624d667a 100644
--- a/ydb/core/viewer/json_topicinfo.h
+++ b/ydb/core/viewer/viewer_topicinfo.h
@@ -1,14 +1,10 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tablet/tablet_counters_aggregator.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
+#include "json_handlers.h"
 #include "viewer.h"
+#include <ydb/core/tablet/tablet_counters_aggregator.h>
+#include <ydb/library/actors/core/actor_bootstrapped.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -90,69 +86,51 @@ class TJsonTopicInfo : public TActorBootstrapped<TJsonTopicInfo> {
         ctx.Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         Die(ctx);
     }
-};
-
-template <>
-struct TJsonRequestSchema<TJsonTopicInfo> {
-    static YAML::Node GetSchema() {
-        return TProtoToYaml::ProtoToYamlSchema<TEvTabletCounters::TEvTabletLabeledCountersResponse::ProtoRecordType>();
-    }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonTopicInfo> {
-    static YAML::Node GetParameters() {
-        return YAML::Load(R"___(
-            - name: path
-              in: query
-              description: schema path
-              required: true
-              type: string
-            - name: client
-              in: query
-              description: client name
-              required: false
-              type: string
-              default: total
-            - name: enums
-              in: query
-              description: convert enums to strings
-              required: false
-              type: boolean
-            - name: all
-              in: query
-              description: return all topics and all clients
-              required: false
-              type: boolean
-              default: false
-            - name: ui64
-              in: query
-              description: return ui64 as number
-              required: false
-              type: boolean
-            - name: timeout
-              in: query
-              description: timeout in ms
-              required: false
-              type: integer
-              default: 10000
-            )___");
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Topic information",
+            .Description = "Information about topic",
+        });
+        yaml.AddParameter({
+            .Name = "path",
+            .Description = "schema path",
+            .Type = "string",
+            .Required = true,
+        });
+        yaml.AddParameter({
+            .Name = "client",
+            .Description = "client name",
+            .Type = "string",
+            .Default = "total",
+        });
+        yaml.AddParameter({
+            .Name = "enums",
+            .Description = "convert enums to strings",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "all",
+            .Description = "return all topics and all clients",
+            .Type = "boolean",
+            .Default = "false",
+        });
+        yaml.AddParameter({
+            .Name = "ui64",
+            .Description = "return ui64 as number",
+            .Type = "boolean",
+        });
+        yaml.AddParameter({
+            .Name = "timeout",
+            .Description = "timeout in ms",
+            .Type = "integer",
+            .Default = "10000",
+        });
+        yaml.SetResponseSchema(TProtoToYaml::ProtoToYamlSchema<TEvTabletCounters::TEvTabletLabeledCountersResponse::ProtoRecordType>());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonTopicInfo> {
-    static TString GetSummary() {
-        return "Topic information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonTopicInfo> {
-    static TString GetDescription() {
-        return "Information about topic";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/viewer_ut.cpp b/ydb/core/viewer/viewer_ut.cpp
index bbc2e5cf1938..f854bed5a06b 100644
--- a/ydb/core/viewer/viewer_ut.cpp
+++ b/ydb/core/viewer/viewer_ut.cpp
@@ -10,10 +10,9 @@
 #include <util/string/join.h>
 #include <ydb/core/viewer/protos/viewer.pb.h>
 #include <ydb/core/blobstorage/base/blobstorage_events.h>
-#include "json_handlers.h"
-#include "json_tabletinfo.h"
-#include "json_vdiskinfo.h"
-#include "json_pdiskinfo.h"
+#include "viewer_tabletinfo.h"
+#include "viewer_vdiskinfo.h"
+#include "viewer_pdiskinfo.h"
 #include "query_autocomplete_helper.h"
 
 #include <library/cpp/testing/unittest/registar.h>
diff --git a/ydb/core/viewer/json_vdiskinfo.h b/ydb/core/viewer/viewer_vdiskinfo.h
similarity index 80%
rename from ydb/core/viewer/json_vdiskinfo.h
rename to ydb/core/viewer/viewer_vdiskinfo.h
index 0675c4cd407b..17c0bd740d42 100644
--- a/ydb/core/viewer/json_vdiskinfo.h
+++ b/ydb/core/viewer/viewer_vdiskinfo.h
@@ -1,10 +1,4 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/util/tuples.h>
 #include "json_wb_req.h"
 
 namespace std {
@@ -43,8 +37,7 @@ struct hash<NKikimrBlobStorage::TVDiskID> {
 
 }
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 template <>
 struct TWhiteboardInfo<NKikimrWhiteboard::TEvVDiskStateResponse> {
@@ -78,19 +71,4 @@ struct TWhiteboardInfo<NKikimrWhiteboard::TEvVDiskStateResponse> {
 
 using TJsonVDiskInfo = TJsonWhiteboardRequest<TEvWhiteboard::TEvVDiskStateRequest, TEvWhiteboard::TEvVDiskStateResponse>;
 
-template <>
-struct TJsonRequestSummary<TJsonVDiskInfo> {
-    static TString GetSummary() {
-        return "VDisk information";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonVDiskInfo> {
-    static TString GetDescription() {
-        return "VDisk information";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/json_whoami.h b/ydb/core/viewer/viewer_whoami.h
similarity index 82%
rename from ydb/core/viewer/json_whoami.h
rename to ydb/core/viewer/viewer_whoami.h
index 36e3715268fd..cf1a6eee7927 100644
--- a/ydb/core/viewer/json_whoami.h
+++ b/ydb/core/viewer/viewer_whoami.h
@@ -1,18 +1,13 @@
 #pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/mon.h>
+#include "json_handlers.h"
+#include "viewer.h"
+#include <ydb/core/base/appdata_fwd.h>
 #include <library/cpp/json/json_value.h>
 #include <library/cpp/json/json_writer.h>
-#include <contrib/libs/yaml-cpp/include/yaml-cpp/yaml.h>
-#include <library/cpp/yaml/as/tstring.h>
-#include <ydb/core/base/tablet_pipe.h>
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/tx/schemeshard/schemeshard.h>
-#include <ydb/core/tx/tx_proxy/proxy.h>
-#include "viewer.h"
+#include <ydb/library/aclib/aclib.h>
+#include <ydb/library/actors/core/actor_bootstrapped.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 
@@ -80,11 +75,8 @@ class TJsonWhoAmI : public TActorBootstrapped<TJsonWhoAmI> {
         ctx.Send(Event->Sender, new NMon::TEvHttpInfoRes(Viewer->GetHTTPGATEWAYTIMEOUT(Event->Get()), 0, NMon::IEvHttpInfoRes::EContentType::Custom));
         Die(ctx);
     }
-};
 
-template <>
-struct TJsonRequestSchema<TJsonWhoAmI> {
-    static YAML::Node GetSchema() {
+    static YAML::Node GetSwaggerSchema() {
         return YAML::Load(R"___(
             type: object
             title: WhoAmI
@@ -114,28 +106,17 @@ struct TJsonRequestSchema<TJsonWhoAmI> {
                     description: Is user allowed to do unrestricted changes in the system
             )___");
     }
-};
 
-template <>
-struct TJsonRequestParameters<TJsonWhoAmI> {
-    static YAML::Node GetParameters() {
-        return {};
+    static YAML::Node GetSwagger() {
+        TSimpleYamlBuilder yaml({
+            .Method = "get",
+            .Tag = "viewer",
+            .Summary = "Information about current user",
+            .Description = "Returns information about user token",
+        });
+        yaml.SetResponseSchema(GetSwaggerSchema());
+        return yaml;
     }
 };
 
-template <>
-struct TJsonRequestSummary<TJsonWhoAmI> {
-    static TString GetSummary() {
-        return "Information about current user";
-    }
-};
-
-template <>
-struct TJsonRequestDescription<TJsonWhoAmI> {
-    static TString GetDescription() {
-        return "Returns information about user token";
-    }
-};
-
-}
 }
diff --git a/ydb/core/viewer/wb_aggregate.cpp b/ydb/core/viewer/wb_aggregate.cpp
index 7f3d56d64b76..45e23a53a622 100644
--- a/ydb/core/viewer/wb_aggregate.cpp
+++ b/ydb/core/viewer/wb_aggregate.cpp
@@ -1,7 +1,6 @@
 #include "wb_aggregate.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 void AggregateMessage(::google::protobuf::Message& protoTo, const ::google::protobuf::Message& protoFrom) {
     const Reflection& reflectionFrom = *protoFrom.GetReflection();
@@ -177,4 +176,3 @@ void AggregateMessage(::google::protobuf::Message& protoTo, const ::google::prot
 }
 
 }
-}
diff --git a/ydb/core/viewer/wb_aggregate.h b/ydb/core/viewer/wb_aggregate.h
index 7d09f1565f6c..c9b589f32115 100644
--- a/ydb/core/viewer/wb_aggregate.h
+++ b/ydb/core/viewer/wb_aggregate.h
@@ -1,19 +1,17 @@
 #pragma once
-#include <util/string/vector.h>
 #include <ydb/core/node_whiteboard/node_whiteboard.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NNodeWhiteboard;
 using namespace ::google::protobuf;
 
-template <typename ResponseType>
+template<typename ResponseType>
 struct TWhiteboardInfo;
 
 void AggregateMessage(::google::protobuf::Message& protoTo, const ::google::protobuf::Message& protoFrom);
 
-template <typename ResponseType>
+template<typename ResponseType>
 class TWhiteboardAggregator {
 public:
     using TResponseType = ResponseType;
@@ -46,4 +44,3 @@ THolder<ResponseType> AggregateWhiteboardResponses(TMap<TTabletId, THolder<Respo
 }
 
 }
-}
diff --git a/ydb/core/viewer/wb_filter.cpp b/ydb/core/viewer/wb_filter.cpp
index d7899f5edfba..9fa4fdfc339f 100644
--- a/ydb/core/viewer/wb_filter.cpp
+++ b/ydb/core/viewer/wb_filter.cpp
@@ -1,7 +1,6 @@
 #include "wb_filter.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 template <>
 i32 TFieldProtoValueExtractor<i32>::ExtractValue(const Reflection& reflection, const Message& element) const {
@@ -97,4 +96,3 @@ TMessageValue TFieldProtoValueExtractor<TMessageValue>::ExtractValue(const Refle
 }
 
 }
-}
diff --git a/ydb/core/viewer/wb_filter.h b/ydb/core/viewer/wb_filter.h
index 64926899e70c..8222c58366c1 100644
--- a/ydb/core/viewer/wb_filter.h
+++ b/ydb/core/viewer/wb_filter.h
@@ -1,15 +1,14 @@
 #pragma once
+#include <util/string/split.h>
 #include <util/string/vector.h>
 #include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <util/string/split.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NNodeWhiteboard;
 using namespace ::google::protobuf;
 
-template <typename ResponseType>
+template<typename ResponseType>
 struct TWhiteboardInfo;
 
 struct TEnumValue {
@@ -552,4 +551,3 @@ void FilterWhiteboardResponses(ResponseType& response, const TString& filters) {
 }
 
 }
-}
diff --git a/ydb/core/viewer/wb_group.h b/ydb/core/viewer/wb_group.h
index 731c5db9f4b1..2250a45daaf7 100644
--- a/ydb/core/viewer/wb_group.h
+++ b/ydb/core/viewer/wb_group.h
@@ -1,15 +1,14 @@
 #pragma once
+#include <util/string/split.h>
 #include <util/string/vector.h>
 #include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <util/string/split.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NNodeWhiteboard;
 using namespace ::google::protobuf;
 
-template <typename ResponseType>
+template<typename ResponseType>
 struct TWhiteboardInfo;
 
 template<typename ResponseType>
@@ -304,4 +303,3 @@ void GroupWhiteboardResponses(ResponseType& response, const TString& fields, boo
 }
 
 }
-}
diff --git a/ydb/core/viewer/wb_merge.cpp b/ydb/core/viewer/wb_merge.cpp
index cca5dc1d9deb..cc092ad4540a 100644
--- a/ydb/core/viewer/wb_merge.cpp
+++ b/ydb/core/viewer/wb_merge.cpp
@@ -1,7 +1,6 @@
 #include "wb_merge.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NNodeWhiteboard;
 using namespace ::google::protobuf;
@@ -216,4 +215,3 @@ void TWhiteboardMergerBase::ProtoMerge(google::protobuf::Message& protoTo, const
 }
 
 }
-}
diff --git a/ydb/core/viewer/wb_merge.h b/ydb/core/viewer/wb_merge.h
index e9912de2ae6e..64d37d0bfd10 100644
--- a/ydb/core/viewer/wb_merge.h
+++ b/ydb/core/viewer/wb_merge.h
@@ -1,23 +1,21 @@
 #pragma once
+#include "wb_filter.h"
+#include "wb_group.h"
 #include <unordered_map>
 #include <util/string/vector.h>
 #include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include "wb_filter.h"
-#include "wb_group.h"
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NNodeWhiteboard;
 using namespace ::google::protobuf;
 
-struct TWhiteboardDefaultInfo {
-};
+struct TWhiteboardDefaultInfo {};
 
-template <typename ResponseType>
+template<typename ResponseType>
 struct TWhiteboardInfo;
 
-template <typename ResponseType>
+template<typename ResponseType>
 struct TWhiteboardMergerComparator {
     bool operator ()(const ResponseType& a, const ResponseType& b) const {
         return a.GetChangeTime() < b.GetChangeTime();
@@ -304,4 +302,3 @@ void MergeWhiteboardResponses(ResponseType& result, TMap<ui32, ResponseType>& re
 }
 
 }
-}
diff --git a/ydb/core/viewer/wb_req.h b/ydb/core/viewer/wb_req.h
index bfd1ff8ba8a9..d808b9e4a063 100644
--- a/ydb/core/viewer/wb_req.h
+++ b/ydb/core/viewer/wb_req.h
@@ -1,25 +1,13 @@
 #pragma once
-
-#pragma once
-#include <ydb/library/actors/core/actor_bootstrapped.h>
-#include <ydb/library/actors/core/interconnect.h>
-#include <ydb/library/actors/core/mon.h>
-
-#include <ydb/library/services/services.pb.h>
-#include <ydb/core/node_whiteboard/node_whiteboard.h>
-#include <ydb/core/viewer/json/json.h>
-#include <ydb/core/base/nameservice.h>
-#include <ydb/library/actors/interconnect/interconnect.h>
-#include <library/cpp/time_provider/time_provider.h>
-#include "viewer.h"
 #include "json_pipe_req.h"
-#include "wb_merge.h"
-#include "wb_group.h"
-#include "wb_filter.h"
 #include "log.h"
+#include "viewer.h"
+#include "wb_filter.h"
+#include "wb_group.h"
+#include "wb_merge.h"
+#include <ydb/library/actors/interconnect/interconnect.h>
 
-namespace NKikimr {
-namespace NViewer {
+namespace NKikimr::NViewer {
 
 using namespace NActors;
 using namespace NNodeWhiteboard;
@@ -297,4 +285,3 @@ class TWhiteboardRequest : public TViewerPipeClient {
 };
 
 }
-}
diff --git a/ydb/core/viewer/ya.make b/ydb/core/viewer/ya.make
index c47429d57b1a..8830cee29367 100644
--- a/ydb/core/viewer/ya.make
+++ b/ydb/core/viewer/ya.make
@@ -4,79 +4,95 @@ RECURSE_FOR_TESTS(
 
 LIBRARY()
 
+IF(BUILD_TYPE == RELEASE OR BUILD_TYPE == RELWITHDEBINFO)
+    CXXFLAGS(-Oz)
+ENDIF()
+
 SRCS(
     browse_db.h
-    browse_pq.h
+    browse_events.h
     browse.h
-    check_access.h
+    browse_pq.h
     counters_hosts.h
-    json_acl.h
-    json_autocomplete.h
-    json_blobindexstat.h
-    json_browse.h
-    json_bscontrollerinfo.h
-    json_bsgroupinfo.h
-    json_cluster.h
-    json_compute.h
-    json_config.h
-    json_content.h
-    json_counters.h
-    json_describe.h
-    json_describe_consumer.h
-    json_describe_topic.h
-    json_local_rpc.h
-    json_getblob.h
-    json_graph.h
+    healthcheck_record.h
+    json_handlers.cpp
+    json_handlers.h
+    json_handlers_browse.cpp
     json_handlers_operation.cpp
     json_handlers_pdisk.cpp
     json_handlers_scheme.cpp
     json_handlers_storage.cpp
     json_handlers_vdisk.cpp
     json_handlers_viewer.cpp
-    json_healthcheck.h
-    json_hiveinfo.h
-    json_hotkeys.h
-    json_labeledcounters.h
-    json_metainfo.h
-    json_netinfo.h
-    json_nodeinfo.h
-    json_nodelist.h
-    json_nodes.h
-    json_pdiskinfo.h
+    json_handlers_pq.cpp
+    json_local_rpc.h
     json_pipe_req.cpp
-    json_query.h
-    json_query_old.h
-    json_render.h
-    json_storage.h
-    json_sysinfo.h
-    json_tabletcounters.h
-    json_tabletinfo.h
-    json_tenants.h
-    json_tenantinfo.h
-    json_topicinfo.h
-    json_pqconsumerinfo.h
+    json_pipe_req.h
+    json_storage_base.h
     json_vdisk_req.h
-    json_vdisk_evict.h
-    json_vdiskinfo.h
-    json_vdiskstat.h
+    json_wb_req.cpp
     json_wb_req.h
-    json_whoami.h
     log.h
     operation_cancel.h
     operation_forget.h
     operation_get.h
     operation_list.h
     pdisk_info.h
+    pdisk_restart.h
     pdisk_status.h
-    scheme_directory.h
-    storage_groups.cpp
     query_autocomplete_helper.h
-    viewer_capabilities.cpp
+    scheme_directory.h
+    storage_groups.h
+    vdisk_blobindexstat.h
+    vdisk_evict.h
+    vdisk_getblob.h
+    vdisk_vdiskstat.h
+    viewer_acl.h
+    viewer_autocomplete.h
+    viewer_browse.h
+    viewer_bscontrollerinfo.h
+    viewer_bsgroupinfo.h
+    viewer_capabilities.h
+    viewer_check_access.h
+    viewer_cluster.h
+    viewer_compute.h
+    viewer_config.h
+    viewer_content.h
+    viewer_counters.h
+    viewer_describe_consumer.h
+    viewer_describe.h
+    viewer_describe_topic.h
+    viewer_graph.h
+    viewer_healthcheck.h
+    viewer_helper.h
+    viewer_hiveinfo.h
+    viewer_hivestats.h
+    viewer_hotkeys.h
+    viewer_labeled_counters.h
+    viewer_metainfo.h
+    viewer_netinfo.h
+    viewer_nodeinfo.h
+    viewer_nodelist.h
+    viewer_nodes.h
+    viewer_pdiskinfo.h
+    viewer_pqconsumerinfo.h
+    viewer_query.h
+    viewer_query_old.h
+    viewer_render.h
     viewer_request.cpp
     viewer_request.h
-    viewer.cpp
+    viewer_storage.h
+    viewer_storage_usage.h
+    viewer_sysinfo.h
+    viewer_tabletcounters.h
+    viewer_tabletinfo.h
+    viewer_tenantinfo.h
+    viewer_tenants.h
+    viewer_topicinfo.h
+    viewer_vdiskinfo.h
+    viewer_whoami.h
     viewer.h
-    viewer_probes.cpp
+    viewer.cpp
     wb_aggregate.cpp
     wb_aggregate.h
     wb_filter.cpp
@@ -84,6 +100,7 @@ SRCS(
     wb_group.h
     wb_merge.cpp
     wb_merge.h
+    wb_req.h
 )
 
 IF (NOT EXPORT_CMAKE)
diff --git a/ydb/core/viewer/yaml/yaml.cpp b/ydb/core/viewer/yaml/yaml.cpp
index a23afaef2870..c2175e12858d 100644
--- a/ydb/core/viewer/yaml/yaml.cpp
+++ b/ydb/core/viewer/yaml/yaml.cpp
@@ -47,6 +47,9 @@ YAML::Node TProtoToYaml::ProtoToYamlSchema(const ::google::protobuf::Descriptor*
         int oneofFields = descriptor->oneof_decl_count();
         for (int idx = 0; idx < oneofFields; ++idx) {
             const OneofDescriptor* fieldDescriptor = descriptor->oneof_decl(idx);
+            if (fieldDescriptor->name().StartsWith("_")) {
+                continue;
+            }
             properties[fieldDescriptor->name()]["type"] = "oneOf";
         }
         for (int idx = 0; idx < fields; ++idx) {
diff --git a/ydb/core/viewer/yaml/yaml.h b/ydb/core/viewer/yaml/yaml.h
index 8e0869c46ed9..8415cce3c57e 100644
--- a/ydb/core/viewer/yaml/yaml.h
+++ b/ydb/core/viewer/yaml/yaml.h
@@ -1,9 +1,9 @@
 #pragma once
+#include <google/protobuf/message.h>
+#include <library/cpp/yaml/as/tstring.h>
 #include <unordered_map>
 #include <unordered_set>
-#include <google/protobuf/message.h>
 #include <util/stream/output.h>
-#include <library/cpp/yaml/as/tstring.h>
 
 struct TEnumSettings {
     bool ConvertToLowerCase = false;