Remove redundant extra-field annotations from generated models

Author: Kludex

scripts/gen_surface_types.py

@@ -253,6 +253,9 @@ def build(entry: dict[str, str]) -> str:
         source = raw.read_text(encoding="utf-8")
 
     source = re.sub(r"\A# generated by datamodel-codegen:\n#[^\n]*\n", "", source)
+    # Explicit __annotations__ hides declared fields under Python 3.14's deferred annotations.
+    source = source.replace('    __annotations__ = {\n        "__pydantic_extra__": Dict[str, Any],\n    }\n', "")
+    source = source.replace(", Dict,", ",")
     # Keep named aliases only for recursive types; other aliases remain ordinary Python types and unions.
     for node in reversed(ast.parse(source).body):
         if not (
@@ -292,13 +295,6 @@ def build(entry: dict[str, str]) -> str:
     staging = TYPES_DIR / f"_staging_{version}.py"
     try:
         staging.write_text(source, encoding="utf-8")
-        subprocess.run(
-            [
-                "uv", "run", "--frozen", "ruff", "check", "--no-cache",
-                "--select", "F401,UP006,UP035", "--fix", "--unsafe-fixes", str(staging),
-            ],
-            cwd=REPO_ROOT, capture_output=True, check=True,
-        )  # fmt: skip
         subprocess.run(
             ["uv", "run", "--frozen", "ruff", "format", "--no-cache", str(staging)],
             cwd=REPO_ROOT, capture_output=True, check=True,

src/mcp-types/mcp_types/_v2025_11_25/__init__.py

@@ -394,9 +394,6 @@ class GetTaskPayloadResult(WireModel):
     model_config = ConfigDict(
         extra="allow",
     )
-    __annotations__ = {
-        "__pydantic_extra__": dict[str, Any],
-    }
     meta: Annotated[dict[str, Any] | None, Field(alias="_meta")] = None
     """
     See [General fields: `_meta`](https://modelcontextprotocol.io/specification/2025-11-25/basic/index#meta) for notes on `_meta` usage.
@@ -793,9 +790,6 @@ class Meta(WireModel):
     model_config = ConfigDict(
         extra="allow",
     )
-    __annotations__ = {
-        "__pydantic_extra__": dict[str, Any],
-    }
     progress_token: Annotated[ProgressToken | None, Field(alias="progressToken")] = None
     """
     If specified, the caller is requesting out-of-band progress notifications for this request (as represented by notifications/progress). The value of this parameter is an opaque token that will be attached to any subsequent notifications. The receiver is not obligated to provide these notifications.
@@ -953,9 +947,6 @@ class Result(WireModel):
     model_config = ConfigDict(
         extra="allow",
     )
-    __annotations__ = {
-        "__pydantic_extra__": dict[str, Any],
-    }
     meta: Annotated[dict[str, Any] | None, Field(alias="_meta")] = None
     """
     See [General fields: `_meta`](https://modelcontextprotocol.io/specification/2025-11-25/basic/index#meta) for notes on `_meta` usage.
@@ -2656,9 +2647,6 @@ class Data(WireModel):
     model_config = ConfigDict(
         extra="allow",
     )
-    __annotations__ = {
-        "__pydantic_extra__": dict[str, Any],
-    }
     elicitations: list[ElicitRequestURLParams]
 
 

src/mcp-types/mcp_types/_v2026_07_28/__init__.py

@@ -1055,9 +1055,6 @@ class InputSchema(WireModel):
     model_config = ConfigDict(
         extra="allow",
     )
-    __annotations__ = {
-        "__pydantic_extra__": dict[str, Any],
-    }
     schema_: Annotated[str | None, Field(alias="$schema")] = None
     type: Literal["object"]
 
@@ -1073,9 +1070,6 @@ class OutputSchema(WireModel):
     model_config = ConfigDict(
         extra="allow",
     )
-    __annotations__ = {
-        "__pydantic_extra__": dict[str, Any],
-    }
     schema_: Annotated[str | None, Field(alias="$schema")] = None
 
 
@@ -2028,9 +2022,6 @@ class Result(WireModel):
     model_config = ConfigDict(
         extra="allow",
     )
-    __annotations__ = {
-        "__pydantic_extra__": dict[str, Any],
-    }
     meta: Annotated[ResultMetaObject | None, Field(alias="_meta")] = None
     result_type: Annotated[str, Field(alias="resultType")]
     """

tests/types/test_methods.py

@@ -960,6 +960,19 @@ def test_serialize_server_result_preserves_open_type_extras():
     assert sieved["tools"][0]["_meta"] == nested_meta
 
 
+@pytest.mark.parametrize("input_schema", [{}, {"type": "array"}])
+def test_serialize_server_result_rejects_invalid_tool_input_schema(input_schema: dict[str, Any]) -> None:
+    """The 2026 spec requires a tool's input schema to declare `type="object"`, even though it allows extra keys."""
+    result = {
+        "tools": [{"name": "echo", "inputSchema": input_schema}],
+        "resultType": "complete",
+        "ttlMs": 0,
+        "cacheScope": "private",
+    }
+    with pytest.raises(pydantic.ValidationError):
+        methods.serialize_server_result("tools/list", "2026-07-28", result)
+
+
 def test_serialize_server_result_drops_top_level_server_info_on_discover_but_keeps_the_meta_stamp():
     """Server identity moved from the discover body to result `_meta` (spec PR #3002):
     the sieve drops the removed body key and preserves the `_meta` stamp."""