🎨 improve logger output with terminal detection

TODO.md

@@ -18,6 +18,7 @@
 
 ### Bugs
 - [x] BUG: figure out why closing the client seems to hang
+- [ ] Still using the wrong loggers in server (one with terminal, the other, for example)
 
 ## MCP server
 
@@ -30,4 +31,4 @@
 
 - [X] Allow debug logging
 - [x] Implement missing SSE methods
-- [ ] BUG: killing server doesn't seem to kill hanging connections (when using inspector, for example)
+- [x] BUG: killing server doesn't seem to kill hanging connections (when using inspector, for example)

changelog.md

@@ -308,4 +308,12 @@ Consolidated list operation response types into a shared location:
 
 - Moved ListPromptsResult, ListResourcesResult, and ListToolsResult to responses.go
 - Updated both SSE and stdio servers to use the shared types
-- Ensured consistent response structure across all server implementations 
+- Ensured consistent response structure across all server implementations 
+
+# Improved Logger Output
+
+Added conditional logger output based on terminal detection. When output is not going to a terminal, the logger will not use color escape codes, making the output more readable in log files and non-terminal environments.
+
+- Updated both client and server to detect terminal output
+- Added golang.org/x/term dependency for terminal detection
+- Logger now uses NoColor mode when output is not going to a terminal

cmd/mcp-client/main.go

@@ -12,6 +12,7 @@ import (
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
 	"github.com/spf13/cobra"
+	"golang.org/x/term"
 )
 
 var (
@@ -46,9 +47,18 @@ Supports both stdio and SSE transports for client-server communication.`,
 				level = zerolog.InfoLevel
 			}
 
-			// Set up console writer for colored output
-			consoleWriter := zerolog.ConsoleWriter{Out: os.Stderr, TimeFormat: time.RFC3339}
-			logger := zerolog.New(consoleWriter).With().Timestamp()
+			var writer zerolog.ConsoleWriter
+			if term.IsTerminal(int(os.Stderr.Fd())) {
+				writer = zerolog.ConsoleWriter{Out: os.Stderr, TimeFormat: time.RFC3339}
+			} else {
+				writer = zerolog.ConsoleWriter{
+					Out:        os.Stderr,
+					TimeFormat: time.RFC3339,
+					NoColor:    true,
+				}
+			}
+
+			logger := zerolog.New(writer).With().Timestamp()
 			if withCaller {
 				logger = logger.Caller()
 			}

cmd/mcp-server/main.go

@@ -18,6 +18,7 @@ import (
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
 	"github.com/spf13/cobra"
+	"golang.org/x/term"
 )
 
 var (
@@ -50,9 +51,18 @@ providing a framework for building MCP servers and clients.`,
 				level = zerolog.InfoLevel
 			}
 
-			// Set up console writer for colored output
-			consoleWriter := zerolog.ConsoleWriter{Out: os.Stderr, TimeFormat: time.RFC3339}
-			logger := zerolog.New(consoleWriter).With().Timestamp()
+			var writer zerolog.ConsoleWriter
+			if term.IsTerminal(int(os.Stderr.Fd())) {
+				writer = zerolog.ConsoleWriter{Out: os.Stderr, TimeFormat: time.RFC3339}
+			} else {
+				writer = zerolog.ConsoleWriter{
+					Out:        os.Stderr,
+					TimeFormat: time.RFC3339,
+					NoColor:    true,
+				}
+			}
+
+			logger := zerolog.New(writer).With().Timestamp()
 			if withCaller {
 				logger = logger.Caller()
 			}

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/gorilla/mux v1.8.1
 	github.com/r3labs/sse/v2 v2.10.0
 	github.com/rs/zerolog v1.33.0
+	golang.org/x/term v0.28.0
 )
 
 require (
@@ -23,5 +24,5 @@ require (
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/spf13/cobra v1.8.1
-	golang.org/x/sys v0.28.0 // indirect
+	golang.org/x/sys v0.29.0 // indirect
 )

go.sum

@@ -2,6 +2,7 @@ github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSV
 github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
@@ -14,9 +15,11 @@ github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovk
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/r3labs/sse/v2 v2.10.0 h1:hFEkLLFY4LDifoHdiCN/LlGBAdVJYsANaLqNYa1l/v0=
 github.com/r3labs/sse/v2 v2.10.0/go.mod h1:Igau6Whc+F17QUgML1fYe1VPZzTV6EMCnYktEmkNJ7I=
 github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
@@ -30,14 +33,23 @@ github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/net v0.0.0-20191116160921-f9c825593386/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.33.0 h1:74SYHlV8BIgHIFC/LrYkOGIwL19eTYXQ5wc6TBuO36I=
+golang.org/x/net v0.33.0/go.mod h1:HXLR5J+9DxmrqMwG9qjGCxZ+zKXxBru04zlTvWlWuN4=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
+golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.27.0 h1:WP60Sv1nlK1T6SupCHbXzSaN0b9wUmsPoRS9b61A23Q=
+golang.org/x/term v0.27.0/go.mod h1:iMsnZpn0cago0GOrHO2+Y7u7JPn5AylBrcoWkElMTSM=
+golang.org/x/term v0.28.0 h1:/Ts8HFuMR2E6IP/jlo7QVLZHggjKQbhu/7H0LJFr3Gg=
+golang.org/x/term v0.28.0/go.mod h1:Sw/lC2IAUZ92udQNf3WodGtn4k/XoLyZoh8v/8uiwek=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 gopkg.in/cenkalti/backoff.v1 v1.1.0 h1:Arh75ttbsvlpVA7WtVpH4u9h6Zl46xuptxqLxPiSo4Y=
 gopkg.in/cenkalti/backoff.v1 v1.1.0/go.mod h1:J6Vskwqd+OMVJl8C33mmtxTBs2gyzfv7UDAkHu8BrjI=

pkg/server/stdio.go

@@ -306,18 +306,3 @@ func (s *StdioServer) sendError(id *json.RawMessage, code int, message string, d
 	s.logger.Debug().Interface("response", response).Msg("Sending error response")
 	return s.writer.Encode(response)
 }
-
-type ListPromptsResult struct {
-	Prompts    []protocol.Prompt `json:"prompts"`
-	NextCursor string            `json:"nextCursor"`
-}
-
-type ListResourcesResult struct {
-	Resources  []protocol.Resource `json:"resources"`
-	NextCursor string              `json:"nextCursor"`
-}
-
-type ListToolsResult struct {
-	Tools      []protocol.Tool `json:"tools"`
-	NextCursor string          `json:"nextCursor"`
-}