diff --git a/benchmark/rust-toolchain b/benchmark/rust-toolchain
index 73a401ca..e02da0b2 100644
--- a/benchmark/rust-toolchain
+++ b/benchmark/rust-toolchain
@@ -1 +1 @@
-nightly-2024-02-09
\ No newline at end of file
+nightly-2024-04-26
\ No newline at end of file
diff --git a/core/src/address.rs b/core/src/address.rs
index 6214601b..bfd331c2 100644
--- a/core/src/address.rs
+++ b/core/src/address.rs
@@ -203,6 +203,7 @@ impl FromStr for Address {
     }
 }
 
+#[allow(clippy::to_string_trait_impl)]
 impl ToString for Address {
     fn to_string(&self) -> String {
         Key::from(*self).to_formatted_string()
diff --git a/examples/ourcoin/rust-toolchain b/examples/ourcoin/rust-toolchain
index 73a401ca..e02da0b2 100644
--- a/examples/ourcoin/rust-toolchain
+++ b/examples/ourcoin/rust-toolchain
@@ -1 +1 @@
-nightly-2024-02-09
\ No newline at end of file
+nightly-2024-04-26
\ No newline at end of file
diff --git a/justfile b/justfile
index e0065dad..11833e25 100644
--- a/justfile
+++ b/justfile
@@ -1,5 +1,5 @@
 CARGO_ODRA_GIT_REPO := "https://github.com/odradev/cargo-odra"
-CARGO_ODRA_BRANCH := "release/0.1.2"
+CARGO_ODRA_BRANCH := "release/0.1.3"
 BINARYEN_VERSION := "version_116"
 BINARYEN_CHECKSUM := "c55b74f3109cdae97490faf089b0286d3bba926bb6ea5ed00c8c784fc53718fd"
 
@@ -36,7 +36,7 @@ install-cargo-odra:
 prepare-test-env: install-cargo-odra
     rustup target add wasm32-unknown-unknown
     rustup component add llvm-tools-preview
-    cargo install grcov
+    cargo +stable install grcov
     sudo apt install wabt
     wget https://github.com/WebAssembly/binaryen/releases/download/{{BINARYEN_VERSION}}/binaryen-{{BINARYEN_VERSION}}-x86_64-linux.tar.gz || { echo "Download failed"; exit 1; }
     sha256sum binaryen-{{BINARYEN_VERSION}}-x86_64-linux.tar.gz | grep {{BINARYEN_CHECKSUM}} || { echo "Checksum verification failed"; exit 1; }
diff --git a/modules/resources/casper_contract_schemas/cep18_client_contract_schema.json b/modules/resources/casper_contract_schemas/cep18_client_contract_schema.json
index 0204f7a9..9d050ac1 100644
--- a/modules/resources/casper_contract_schemas/cep18_client_contract_schema.json
+++ b/modules/resources/casper_contract_schemas/cep18_client_contract_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "Cep18ClientContract",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [],
   "errors": [],
   "entry_points": [
diff --git a/modules/resources/casper_contract_schemas/cep18_schema.json b/modules/resources/casper_contract_schemas/cep18_schema.json
index 86cb0648..d7d51b8c 100644
--- a/modules/resources/casper_contract_schemas/cep18_schema.json
+++ b/modules/resources/casper_contract_schemas/cep18_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "Cep18",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [
     {
       "struct": {
@@ -199,6 +199,52 @@
           }
         ]
       }
+    },
+    {
+      "enum": {
+        "name": "Cep18Modality",
+        "description": null,
+        "variants": [
+          {
+            "name": "None",
+            "description": null,
+            "discriminant": 0,
+            "ty": "Unit"
+          },
+          {
+            "name": "MintAndBurn",
+            "description": null,
+            "discriminant": 1,
+            "ty": "Unit"
+          }
+        ]
+      }
+    },
+    {
+      "enum": {
+        "name": "SecurityBadge",
+        "description": null,
+        "variants": [
+          {
+            "name": "Admin",
+            "description": null,
+            "discriminant": 0,
+            "ty": "Unit"
+          },
+          {
+            "name": "Minter",
+            "description": null,
+            "discriminant": 1,
+            "ty": "Unit"
+          },
+          {
+            "name": "None",
+            "description": null,
+            "discriminant": 2,
+            "ty": "Unit"
+          }
+        ]
+      }
     }
   ],
   "errors": [
diff --git a/modules/resources/casper_contract_schemas/erc1155_receiver_schema.json b/modules/resources/casper_contract_schemas/erc1155_receiver_schema.json
index 64eba34c..a288f11b 100644
--- a/modules/resources/casper_contract_schemas/erc1155_receiver_schema.json
+++ b/modules/resources/casper_contract_schemas/erc1155_receiver_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "Erc1155Receiver",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [
     {
       "struct": {
diff --git a/modules/resources/casper_contract_schemas/erc1155_token_schema.json b/modules/resources/casper_contract_schemas/erc1155_token_schema.json
index ee9746d7..dcd7794b 100644
--- a/modules/resources/casper_contract_schemas/erc1155_token_schema.json
+++ b/modules/resources/casper_contract_schemas/erc1155_token_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "Erc1155Token",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [
     {
       "struct": {
diff --git a/modules/resources/casper_contract_schemas/erc721_receiver_schema.json b/modules/resources/casper_contract_schemas/erc721_receiver_schema.json
index ee96b96c..cd0a7edc 100644
--- a/modules/resources/casper_contract_schemas/erc721_receiver_schema.json
+++ b/modules/resources/casper_contract_schemas/erc721_receiver_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "Erc721Receiver",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [],
   "errors": [],
   "entry_points": [
diff --git a/modules/resources/casper_contract_schemas/erc721_token_schema.json b/modules/resources/casper_contract_schemas/erc721_token_schema.json
index f4d0965a..a0ef9cda 100644
--- a/modules/resources/casper_contract_schemas/erc721_token_schema.json
+++ b/modules/resources/casper_contract_schemas/erc721_token_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "Erc721Token",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [
     {
       "struct": {
diff --git a/modules/resources/casper_contract_schemas/mock_cep78_operator_schema.json b/modules/resources/casper_contract_schemas/mock_cep78_operator_schema.json
new file mode 100644
index 00000000..b818be18
--- /dev/null
+++ b/modules/resources/casper_contract_schemas/mock_cep78_operator_schema.json
@@ -0,0 +1,228 @@
+{
+  "casper_contract_schema_version": 1,
+  "toolchain": "rustc 1.78.0-nightly (98aa3624b 2024-02-08)",
+  "authors": [
+    "Jakub Płaskonka <kuba@odra.dev>",
+    "Krzysztof Pobiarżyn <krzysztof@odra.dev>",
+    "Maciej Zieliński <maciej@odra.dev>"
+  ],
+  "repository": "https://github.com/odradev/odra",
+  "homepage": null,
+  "contract_name": "MockCep78Operator",
+  "contract_version": "1.1.0",
+  "types": [],
+  "errors": [],
+  "entry_points": [
+    {
+      "name": "set_address",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "nft_contract",
+          "description": null,
+          "ty": "Key",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "mint",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "token_metadata",
+          "description": null,
+          "ty": "String",
+          "optional": false
+        },
+        {
+          "name": "is_reverse_lookup_enabled",
+          "description": null,
+          "ty": "Bool",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "mint_with_hash",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "token_metadata",
+          "description": null,
+          "ty": "String",
+          "optional": false
+        },
+        {
+          "name": "token_hash",
+          "description": null,
+          "ty": "String",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "burn",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "token_id",
+          "description": null,
+          "ty": "U64",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "mint_for",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "token_owner",
+          "description": null,
+          "ty": "Key",
+          "optional": false
+        },
+        {
+          "name": "token_metadata",
+          "description": null,
+          "ty": "String",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "transfer",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "token_id",
+          "description": null,
+          "ty": "U64",
+          "optional": false
+        },
+        {
+          "name": "target",
+          "description": null,
+          "ty": "Key",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "transfer_from",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "token_id",
+          "description": null,
+          "ty": "U64",
+          "optional": false
+        },
+        {
+          "name": "source",
+          "description": null,
+          "ty": "Key",
+          "optional": false
+        },
+        {
+          "name": "target",
+          "description": null,
+          "ty": "Key",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "approve",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "spender",
+          "description": null,
+          "ty": "Key",
+          "optional": false
+        },
+        {
+          "name": "token_id",
+          "description": null,
+          "ty": "U64",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "revoke",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "token_id",
+          "description": null,
+          "ty": "U64",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    }
+  ],
+  "events": [],
+  "call": {
+    "wasm_file_name": "MockCep78Operator.wasm",
+    "description": null,
+    "arguments": [
+      {
+        "name": "odra_cfg_package_hash_key_name",
+        "description": "The arg name for the package hash key name.",
+        "ty": "String",
+        "optional": false
+      },
+      {
+        "name": "odra_cfg_allow_key_override",
+        "description": "The arg name for the allow key override.",
+        "ty": "Bool",
+        "optional": false
+      },
+      {
+        "name": "odra_cfg_is_upgradable",
+        "description": "The arg name for the contract upgradeability setting.",
+        "ty": "Bool",
+        "optional": false
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/modules/resources/casper_contract_schemas/mock_cep78_transfer_filter_schema.json b/modules/resources/casper_contract_schemas/mock_cep78_transfer_filter_schema.json
new file mode 100644
index 00000000..134a765b
--- /dev/null
+++ b/modules/resources/casper_contract_schemas/mock_cep78_transfer_filter_schema.json
@@ -0,0 +1,67 @@
+{
+  "casper_contract_schema_version": 1,
+  "toolchain": "rustc 1.78.0-nightly (98aa3624b 2024-02-08)",
+  "authors": [
+    "Jakub Płaskonka <kuba@odra.dev>",
+    "Krzysztof Pobiarżyn <krzysztof@odra.dev>",
+    "Maciej Zieliński <maciej@odra.dev>"
+  ],
+  "repository": "https://github.com/odradev/odra",
+  "homepage": null,
+  "contract_name": "MockCep78TransferFilter",
+  "contract_version": "1.1.0",
+  "types": [],
+  "errors": [],
+  "entry_points": [
+    {
+      "name": "set_return_value",
+      "description": "",
+      "is_mutable": true,
+      "arguments": [
+        {
+          "name": "return_value",
+          "description": null,
+          "ty": "U8",
+          "optional": false
+        }
+      ],
+      "return_ty": "Unit",
+      "is_contract_context": true,
+      "access": "public"
+    },
+    {
+      "name": "can_transfer",
+      "description": "",
+      "is_mutable": false,
+      "arguments": [],
+      "return_ty": "U8",
+      "is_contract_context": true,
+      "access": "public"
+    }
+  ],
+  "events": [],
+  "call": {
+    "wasm_file_name": "MockCep78TransferFilter.wasm",
+    "description": null,
+    "arguments": [
+      {
+        "name": "odra_cfg_package_hash_key_name",
+        "description": "The arg name for the package hash key name.",
+        "ty": "String",
+        "optional": false
+      },
+      {
+        "name": "odra_cfg_allow_key_override",
+        "description": "The arg name for the allow key override.",
+        "ty": "Bool",
+        "optional": false
+      },
+      {
+        "name": "odra_cfg_is_upgradable",
+        "description": "The arg name for the contract upgradeability setting.",
+        "ty": "Bool",
+        "optional": false
+      }
+    ]
+  }
+}
\ No newline at end of file
diff --git a/modules/resources/casper_contract_schemas/mock_dummy_contract_schema.json b/modules/resources/casper_contract_schemas/mock_dummy_contract_schema.json
index d25439e5..83b10e48 100644
--- a/modules/resources/casper_contract_schemas/mock_dummy_contract_schema.json
+++ b/modules/resources/casper_contract_schemas/mock_dummy_contract_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "MockDummyContract",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [],
   "errors": [],
   "entry_points": [],
diff --git a/modules/resources/casper_contract_schemas/ownable2_step_schema.json b/modules/resources/casper_contract_schemas/ownable2_step_schema.json
index 9c668e98..452df4f7 100644
--- a/modules/resources/casper_contract_schemas/ownable2_step_schema.json
+++ b/modules/resources/casper_contract_schemas/ownable2_step_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "Ownable2Step",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [
     {
       "struct": {
diff --git a/modules/resources/casper_contract_schemas/ownable_schema.json b/modules/resources/casper_contract_schemas/ownable_schema.json
index 84c419fc..366171d9 100644
--- a/modules/resources/casper_contract_schemas/ownable_schema.json
+++ b/modules/resources/casper_contract_schemas/ownable_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "Ownable",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [
     {
       "struct": {
diff --git a/modules/resources/casper_contract_schemas/test_cep78_schema.json b/modules/resources/casper_contract_schemas/test_cep78_schema.json
index 521fb72c..23c700fb 100644
--- a/modules/resources/casper_contract_schemas/test_cep78_schema.json
+++ b/modules/resources/casper_contract_schemas/test_cep78_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "TestCep78",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [
     {
       "struct": {
diff --git a/modules/resources/casper_contract_schemas/wrapped_native_token_schema.json b/modules/resources/casper_contract_schemas/wrapped_native_token_schema.json
index 836c00a6..48de3d02 100644
--- a/modules/resources/casper_contract_schemas/wrapped_native_token_schema.json
+++ b/modules/resources/casper_contract_schemas/wrapped_native_token_schema.json
@@ -9,7 +9,7 @@
   "repository": "https://github.com/odradev/odra",
   "homepage": null,
   "contract_name": "WrappedNativeToken",
-  "contract_version": "1.0.0",
+  "contract_version": "1.1.0",
   "types": [
     {
       "struct": {
diff --git a/modules/resources/legacy/mock_cep78_operator_schema.json b/modules/resources/legacy/mock_cep78_operator_schema.json
new file mode 100644
index 00000000..7b64a240
--- /dev/null
+++ b/modules/resources/legacy/mock_cep78_operator_schema.json
@@ -0,0 +1,199 @@
+{
+  "name": "MockCep78Operator",
+  "events": [],
+  "entrypoints": [
+    {
+      "name": "set_address",
+      "args": [
+        {
+          "name": "nft_contract",
+          "ty": "Key",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "mint",
+      "args": [
+        {
+          "name": "token_metadata",
+          "ty": "String",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        },
+        {
+          "name": "is_reverse_lookup_enabled",
+          "ty": "Bool",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "mint_with_hash",
+      "args": [
+        {
+          "name": "token_metadata",
+          "ty": "String",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        },
+        {
+          "name": "token_hash",
+          "ty": "String",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "burn",
+      "args": [
+        {
+          "name": "token_id",
+          "ty": "U64",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "mint_for",
+      "args": [
+        {
+          "name": "token_owner",
+          "ty": "Key",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        },
+        {
+          "name": "token_metadata",
+          "ty": "String",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "transfer",
+      "args": [
+        {
+          "name": "token_id",
+          "ty": "U64",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        },
+        {
+          "name": "target",
+          "ty": "Key",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "transfer_from",
+      "args": [
+        {
+          "name": "token_id",
+          "ty": "U64",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        },
+        {
+          "name": "source",
+          "ty": "Key",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        },
+        {
+          "name": "target",
+          "ty": "Key",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "approve",
+      "args": [
+        {
+          "name": "spender",
+          "ty": "Key",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        },
+        {
+          "name": "token_id",
+          "ty": "U64",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "revoke",
+      "args": [
+        {
+          "name": "token_id",
+          "ty": "U64",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    }
+  ]
+}
\ No newline at end of file
diff --git a/modules/resources/legacy/mock_cep78_transfer_filter_schema.json b/modules/resources/legacy/mock_cep78_transfer_filter_schema.json
new file mode 100644
index 00000000..9fdb22e8
--- /dev/null
+++ b/modules/resources/legacy/mock_cep78_transfer_filter_schema.json
@@ -0,0 +1,30 @@
+{
+  "name": "MockCep78TransferFilter",
+  "events": [],
+  "entrypoints": [
+    {
+      "name": "set_return_value",
+      "args": [
+        {
+          "name": "return_value",
+          "ty": "U8",
+          "is_ref": false,
+          "is_slice": false,
+          "is_required": true
+        }
+      ],
+      "is_mutable": true,
+      "return_ty": "Unit",
+      "ty": "Public",
+      "attributes": []
+    },
+    {
+      "name": "can_transfer",
+      "args": [],
+      "is_mutable": false,
+      "return_ty": "U8",
+      "ty": "Public",
+      "attributes": []
+    }
+  ]
+}
\ No newline at end of file
diff --git a/modules/src/cep78/metadata.rs b/modules/src/cep78/metadata.rs
index 83f3fecd..a1242595 100644
--- a/modules/src/cep78/metadata.rs
+++ b/modules/src/cep78/metadata.rs
@@ -226,7 +226,7 @@ impl Metadata {
 
                 for (property_name, property_type) in token_schema.properties.iter() {
                     if property_type.required
-                        && custom_metadata.attributes.get(property_name).is_none()
+                        && !custom_metadata.attributes.contains_key(property_name)
                     {
                         self.env().revert(CEP78Error::InvalidCustomMetadata)
                     }
diff --git a/modules/src/cep78/modalities.rs b/modules/src/cep78/modalities.rs
index f8761eee..ba94de4e 100644
--- a/modules/src/cep78/modalities.rs
+++ b/modules/src/cep78/modalities.rs
@@ -315,6 +315,7 @@ impl TokenIdentifier {
     }
 }
 
+#[allow(clippy::to_string_trait_impl)]
 impl ToString for TokenIdentifier {
     fn to_string(&self) -> String {
         match self {
diff --git a/modules/src/lib.rs b/modules/src/lib.rs
index 986146f5..48555704 100644
--- a/modules/src/lib.rs
+++ b/modules/src/lib.rs
@@ -1,7 +1,6 @@
 #![doc = "Odra's library of plug and play modules"]
 #![cfg_attr(not(test), no_std)]
 #![cfg_attr(not(test), no_main)]
-#![recursion_limit = "256"]
 
 extern crate alloc;
 
diff --git a/odra-macros/src/ast/event/mod.rs b/odra-macros/src/ast/event/mod.rs
index 233ec847..27e462a3 100644
--- a/odra-macros/src/ast/event/mod.rs
+++ b/odra-macros/src/ast/event/mod.rs
@@ -1,3 +1,4 @@
+use std::collections::HashSet;
 use quote::ToTokens;
 use syn::{punctuated::Punctuated, token::Comma};
 
@@ -21,13 +22,19 @@ impl ToTokens for OdraEventItem {
         let comment = format!("Creates a new instance of the {} event.", ident);
         let doc_attr = quote::quote!(#[doc = #comment]);
 
-        let chain = item.fields
+        let mut tmp = HashSet::<String>::new();
+        let mut chain = vec![];
+
+        item.fields
             .iter()
-            .map(|f| {
+            .for_each(|f| {
                 let ty = &f.ty;
-                quote::quote!(.chain(<#ty as odra::schema::SchemaEvents>::custom_types()))
-            })
-            .collect::<Vec<_>>();
+                let v = quote::quote!(.chain(<#ty as odra::schema::SchemaEvents>::custom_types()));
+                if tmp.insert(v.to_string()) {
+                    chain.push(v);
+                }
+            });
+
 
         let self_item = custom_struct(&name, &item.fields);
 
diff --git a/odra-macros/src/ast/schema/custom_types.rs b/odra-macros/src/ast/schema/custom_types.rs
index 6cf9b607..534db6e7 100644
--- a/odra-macros/src/ast/schema/custom_types.rs
+++ b/odra-macros/src/ast/schema/custom_types.rs
@@ -1,3 +1,5 @@
+use std::collections::HashSet;
+
 use quote::ToTokens;
 
 use crate::{
@@ -29,10 +31,16 @@ impl ToTokens for SchemaCustomTypesItem {
             })
             .collect::<Vec<_>>();
 
-        let chain = types
+        let mut tmp = HashSet::<String>::new();
+        let mut chain = vec![];
+        types
             .iter()
-            .map(|t| quote::quote!(.chain(<#t as odra::schema::SchemaCustomTypes>::schema_types())))
-            .collect::<Vec<_>>();
+            .for_each(|t| {
+                let v = quote::quote!(.chain(<#t as odra::schema::SchemaCustomTypes>::schema_types()));
+                if tmp.insert(v.to_string()) {
+                    chain.push(v);
+                }
+            });
 
         let item = quote::quote! {
             #[automatically_derived]
@@ -82,10 +90,8 @@ mod test {
                         .chain(<Option<U256> as odra::schema::SchemaCustomTypes>::schema_types())
                         .chain(<U256 as odra::schema::SchemaCustomTypes>::schema_types())
                         .chain(<Address as odra::schema::SchemaCustomTypes>::schema_types())
-                        .chain(<U256 as odra::schema::SchemaCustomTypes>::schema_types())
                         .chain(<Maybe<String> as odra::schema::SchemaCustomTypes>::schema_types())
                         .chain(<odra::prelude::vec::Vec<Address> as odra::schema::SchemaCustomTypes>::schema_types())
-                        .chain(<U256 as odra::schema::SchemaCustomTypes>::schema_types())
                         .chain(<Self as odra::schema::SchemaEvents>::custom_types())
                         .collect()
                 }
diff --git a/odra-schema/src/custom_type.rs b/odra-schema/src/custom_type.rs
index fd123fe4..fa3b3b7b 100644
--- a/odra-schema/src/custom_type.rs
+++ b/odra-schema/src/custom_type.rs
@@ -55,19 +55,62 @@ impl_schema_custom_types!(
     URef
 );
 
-impl<T: CLTyped> SchemaCustomTypes for Option<T> {}
+impl<T: SchemaCustomTypes> SchemaCustomTypes for Option<T> {
+    fn schema_types() -> Vec<Option<CustomType>> {
+        T::schema_types()
+    }
+}
 
-impl<T: CLTyped> SchemaCustomTypes for Vec<T> {}
+impl<T: SchemaCustomTypes> SchemaCustomTypes for Vec<T> {
+    fn schema_types() -> Vec<Option<CustomType>> {
+        T::schema_types()
+    }
+}
 
-impl<T: CLTyped, E: CLTyped> SchemaCustomTypes for Result<T, E> {}
+impl<T: SchemaCustomTypes, E: SchemaCustomTypes> SchemaCustomTypes for Result<T, E> {
+    fn schema_types() -> Vec<Option<CustomType>> {
+        let mut types = vec![];
+        types.extend(T::schema_types());
+        types.extend(E::schema_types());
+        types
+    }
+}
 
-impl<T: CLTyped, E: CLTyped> SchemaCustomTypes for BTreeMap<T, E> {}
+impl<T: SchemaCustomTypes, E: SchemaCustomTypes> SchemaCustomTypes for BTreeMap<T, E> {
+    fn schema_types() -> Vec<Option<CustomType>> {
+        let mut types = vec![];
+        types.extend(T::schema_types());
+        types.extend(E::schema_types());
+        types
+    }
+}
 
-impl<T1: CLTyped> SchemaCustomTypes for (T1,) {}
+impl<T1: SchemaCustomTypes> SchemaCustomTypes for (T1,) {
+    fn schema_types() -> Vec<Option<CustomType>> {
+        T1::schema_types()
+    }
+}
 
-impl<T1: CLTyped, T2: CLTyped> SchemaCustomTypes for (T1, T2) {}
+impl<T1: SchemaCustomTypes, T2: SchemaCustomTypes> SchemaCustomTypes for (T1, T2) {
+    fn schema_types() -> Vec<Option<CustomType>> {
+        let mut types = vec![];
+        types.extend(T1::schema_types());
+        types.extend(T2::schema_types());
+        types
+    }
+}
 
-impl<T1: CLTyped, T2: CLTyped, T3: CLTyped> SchemaCustomTypes for (T1, T2, T3) {}
+impl<T1: SchemaCustomTypes, T2: SchemaCustomTypes, T3: SchemaCustomTypes> SchemaCustomTypes
+    for (T1, T2, T3)
+{
+    fn schema_types() -> Vec<Option<CustomType>> {
+        let mut types = vec![];
+        types.extend(T1::schema_types());
+        types.extend(T2::schema_types());
+        types.extend(T3::schema_types());
+        types
+    }
+}
 
 impl SchemaCustomTypes for Key {}
 
@@ -137,19 +180,62 @@ impl_schema_events!(
     Bytes
 );
 
-impl<T: CLTyped> SchemaEvents for Option<T> {}
+impl<T: SchemaCustomTypes> SchemaEvents for Option<T> {
+    fn custom_types() -> Vec<Option<CustomType>> {
+        T::schema_types()
+    }
+}
 
-impl<T: CLTyped> SchemaEvents for Vec<T> {}
+impl<T: SchemaCustomTypes> SchemaEvents for Vec<T> {
+    fn custom_types() -> Vec<Option<CustomType>> {
+        T::schema_types()
+    }
+}
 
-impl<T: CLTyped, E: CLTyped> SchemaEvents for Result<T, E> {}
+impl<T: SchemaCustomTypes, E: SchemaCustomTypes> SchemaEvents for Result<T, E> {
+    fn custom_types() -> Vec<Option<CustomType>> {
+        let mut types = vec![];
+        types.extend(T::schema_types());
+        types.extend(E::schema_types());
+        types
+    }
+}
 
-impl<T: CLTyped, E: CLTyped> SchemaEvents for BTreeMap<T, E> {}
+impl<T: SchemaCustomTypes, E: SchemaCustomTypes> SchemaEvents for BTreeMap<T, E> {
+    fn custom_types() -> Vec<Option<CustomType>> {
+        let mut types = vec![];
+        types.extend(T::schema_types());
+        types.extend(E::schema_types());
+        types
+    }
+}
 
-impl<T1: CLTyped> SchemaEvents for (T1,) {}
+impl<T1: SchemaCustomTypes> SchemaEvents for (T1,) {
+    fn custom_types() -> Vec<Option<CustomType>> {
+        T1::schema_types()
+    }
+}
 
-impl<T1: CLTyped, T2: CLTyped> SchemaEvents for (T1, T2) {}
+impl<T1: SchemaCustomTypes, T2: SchemaCustomTypes> SchemaEvents for (T1, T2) {
+    fn custom_types() -> Vec<Option<CustomType>> {
+        let mut types = vec![];
+        types.extend(T1::schema_types());
+        types.extend(T2::schema_types());
+        types
+    }
+}
 
-impl<T1: CLTyped, T2: CLTyped, T3: CLTyped> SchemaEvents for (T1, T2, T3) {}
+impl<T1: SchemaCustomTypes, T2: SchemaCustomTypes, T3: SchemaCustomTypes> SchemaEvents
+    for (T1, T2, T3)
+{
+    fn custom_types() -> Vec<Option<CustomType>> {
+        let mut types = vec![];
+        types.extend(T1::schema_types());
+        types.extend(T2::schema_types());
+        types.extend(T3::schema_types());
+        types
+    }
+}
 
 impl<const COUNT: usize> SchemaEvents for [u8; COUNT] {}
 
diff --git a/rust-toolchain b/rust-toolchain
index 73a401ca..e02da0b2 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-nightly-2024-02-09
\ No newline at end of file
+nightly-2024-04-26
\ No newline at end of file
diff --git a/templates/blank/rust-toolchain b/templates/blank/rust-toolchain
index 73a401ca..e02da0b2 100644
--- a/templates/blank/rust-toolchain
+++ b/templates/blank/rust-toolchain
@@ -1 +1 @@
-nightly-2024-02-09
\ No newline at end of file
+nightly-2024-04-26
\ No newline at end of file
diff --git a/templates/cep18/rust-toolchain b/templates/cep18/rust-toolchain
index 73a401ca..e02da0b2 100644
--- a/templates/cep18/rust-toolchain
+++ b/templates/cep18/rust-toolchain
@@ -1 +1 @@
-nightly-2024-02-09
\ No newline at end of file
+nightly-2024-04-26
\ No newline at end of file
diff --git a/templates/cep78/rust-toolchain b/templates/cep78/rust-toolchain
index 73a401ca..e02da0b2 100644
--- a/templates/cep78/rust-toolchain
+++ b/templates/cep78/rust-toolchain
@@ -1 +1 @@
-nightly-2024-02-09
\ No newline at end of file
+nightly-2024-04-26
\ No newline at end of file
diff --git a/templates/full/rust-toolchain b/templates/full/rust-toolchain
index 73a401ca..e02da0b2 100644
--- a/templates/full/rust-toolchain
+++ b/templates/full/rust-toolchain
@@ -1 +1 @@
-nightly-2024-02-09
\ No newline at end of file
+nightly-2024-04-26
\ No newline at end of file
diff --git a/templates/workspace/rust-toolchain b/templates/workspace/rust-toolchain
index 73a401ca..e02da0b2 100644
--- a/templates/workspace/rust-toolchain
+++ b/templates/workspace/rust-toolchain
@@ -1 +1 @@
-nightly-2024-02-09
\ No newline at end of file
+nightly-2024-04-26
\ No newline at end of file