Bump ty to ==0.0.1a25 (#2350)

* Bump ty to >=0.0.1a25 with type fixes

Follow-up to #2295. Updates ty and fixes compatibility issues with alpha 25, including:

- Updated ignore comment syntax (possibly-unbound-attribute → possibly-missing-attribute)
- Fixed async generator type handling with anext()
- Fixed type narrowing for timeout parameters
- Converted base_url assignments to AnyHttpUrl after string manipulation
- Added CallToolResult to return type annotations
- Removed redundant type casts
- Fixed test form data to use strings instead of bytes

ty alpha 25 has limitations with isinstance() narrowing on unions (see pyproject.toml for details), requiring some targeted type ignores.

* Pin ty to ==0.0.1a25

Alpha releases can have breaking changes, so pin to the tested version.

Author: jlowin

pyproject.toml

@@ -71,7 +71,7 @@ dev = [
     "pytest-timeout>=2.4.0",
     "pytest-xdist>=3.6.1",
     "ruff>=0.12.8",
-    "ty==0.0.1a19",
+    "ty==0.0.1a25",
     "prek>=0.2.12",
 ]
 
@@ -136,12 +136,17 @@ python-version = "3.10"
 
 [tool.ty.rules]
 # Rules with too many errors to fix right now (40+ each)
-no-matching-overload = "ignore" # 126 errors  
+no-matching-overload = "ignore" # 126 errors
 unknown-argument = "ignore"     # 61 errors
 
 # Rules with moderate errors that need more investigation
 call-non-callable = "ignore" # 7 errors
 
+# NOTE: ty currently doesn't support type narrowing with isinstance() on unions
+# See: https://github.com/astral-sh/ty/issues/122 and https://github.com/astral-sh/ty/issues/1113
+# Some code uses `# ty: ignore[invalid-argument-type]` for this limitation.
+# TODO: Remove these ignores once ty supports union narrowing
+
 [tool.ruff.lint]
 fixable = ["ALL"]
 ignore = [

src/fastmcp/client/auth/oauth.py

@@ -297,7 +297,8 @@ async def async_auth_flow(
             response = None
             while True:
                 try:
-                    yielded_request = await gen.asend(response)
+                    # First iteration sends None, subsequent iterations send response
+                    yielded_request = await gen.asend(response)  # ty: ignore[invalid-argument-type]
                     response = yield yielded_request
                 except StopAsyncIteration:
                     break
@@ -306,16 +307,16 @@ async def async_auth_flow(
             logger.debug(
                 "OAuth client not found on server, clearing cache and retrying..."
             )
-
             # Clear cached state and retry once
             self._initialized = False
             await self.token_storage_adapter.clear()
 
+            # Retry with fresh registration
             gen = super().async_auth_flow(request)
             response = None
             while True:
                 try:
-                    yielded_request = await gen.asend(response)
+                    yielded_request = await gen.asend(response)  # ty: ignore[invalid-argument-type]
                     response = yield yielded_request
                 except StopAsyncIteration:
                     break

src/fastmcp/client/client.py

@@ -240,6 +240,7 @@ def __init__(
 
         self._progress_handler = progress_handler
 
+        # Convert timeout to timedelta if needed
         if isinstance(timeout, int | float):
             timeout = datetime.timedelta(seconds=float(timeout))
 
@@ -259,7 +260,7 @@ def __init__(
             "list_roots_callback": None,
             "logging_callback": create_log_callback(log_handler),
             "message_handler": message_handler,
-            "read_timeout_seconds": timeout,
+            "read_timeout_seconds": timeout,  # ty: ignore[invalid-argument-type]
             "client_info": client_info,
         }
 
@@ -852,12 +853,13 @@ async def call_tool_mcp(
         """
         logger.debug(f"[{self.name}] called call_tool: {name}")
 
+        # Convert timeout to timedelta if needed
         if isinstance(timeout, int | float):
             timeout = datetime.timedelta(seconds=float(timeout))
         result = await self.session.call_tool(
             name=name,
             arguments=arguments,
-            read_timeout_seconds=timeout,
+            read_timeout_seconds=timeout,  # ty: ignore[invalid-argument-type]
             progress_callback=progress_handler or self._progress_handler,
         )
         return result

src/fastmcp/experimental/utilities/openapi/director.py

@@ -54,28 +54,27 @@ def build(
         url = self._build_url(route.path, path_params, base_url)
 
         # Step 3: Prepare request data
-        request_data = {
-            "method": route.method.upper(),
-            "url": url,
-            "params": query_params if query_params else None,
-            "headers": header_params if header_params else None,
-        }
+        method: str = route.method.upper()
+        params = query_params if query_params else None
+        headers = header_params if header_params else None
+        json_body: dict[str, Any] | list[Any] | None = None
+        content: str | bytes | None = None
 
         # Step 4: Handle request body
         if body is not None:
             if isinstance(body, dict | list):
-                request_data["json"] = body
+                json_body = body
             else:
-                request_data["content"] = body
+                content = body
 
         # Step 5: Create httpx.Request
         return httpx.Request(
-            method=request_data["method"],
-            url=request_data["url"],
-            params=request_data.get("params"),
-            headers=request_data.get("headers"),
-            json=request_data.get("json"),
-            content=request_data.get("content"),
+            method=method,
+            url=url,
+            params=params,
+            headers=headers,
+            json=json_body,
+            content=content,
         )
 
     def _unflatten_arguments(

src/fastmcp/mcp_config.py

@@ -101,7 +101,7 @@ def _to_server_and_underlying_transport(
             ClientTransport,  # pyright: ignore[reportUnusedImport]
         )
 
-        transport: ClientTransport = super().to_transport()  # pyright: ignore[reportUnknownMemberType, reportAttributeAccessIssue, reportUnknownVariableType]
+        transport: ClientTransport = super().to_transport()  # pyright: ignore[reportUnknownMemberType, reportAttributeAccessIssue, reportUnknownVariableType]  # ty: ignore[unresolved-attribute]
         transport = cast(ClientTransport, transport)
 
         client: Client[ClientTransport] = Client(transport=transport, name=client_name)

src/fastmcp/server/auth/handlers/authorize.py

@@ -13,6 +13,7 @@
 
 from __future__ import annotations
 
+import json
 from typing import TYPE_CHECKING
 
 from mcp.server.auth.handlers.authorize import (
@@ -211,22 +212,23 @@ async def handle(self, request: Request) -> Response:
         # Check if this is a client not found error
         if response.status_code == 400:
             # Try to extract client_id from request for enhanced error
-            client_id = None
+            client_id: str | None = None
             if request.method == "GET":
                 client_id = request.query_params.get("client_id")
             else:
                 form = await request.form()
-                client_id = form.get("client_id")
+                client_id_value = form.get("client_id")
+                # Ensure client_id is a string, not UploadFile
+                if isinstance(client_id_value, str):
+                    client_id = client_id_value
 
             # If we have a client_id and the error is about it not being found,
             # enhance the response
             if client_id:
                 try:
                     # Check if response body contains "not found" error
                     if hasattr(response, "body"):
-                        import json
-
-                        body = json.loads(response.body)
+                        body = json.loads(bytes(response.body))
                         if (
                             body.get("error") == "invalid_request"
                             and "not found" in body.get("error_description", "").lower()

src/fastmcp/server/auth/oauth_proxy.py

@@ -1605,9 +1605,10 @@ def get_routes(
             ):
                 authorize_route_found = True
                 # Replace with our enhanced authorization handler
+                # Note: self.base_url is guaranteed to be set in parent __init__
                 authorize_handler = AuthorizationHandler(
                     provider=self,
-                    base_url=self.base_url,
+                    base_url=self.base_url,  # ty: ignore[invalid-argument-type]
                     server_name=None,  # Could be extended to pass server metadata
                     server_icon_url=None,
                 )

src/fastmcp/server/auth/oidc_proxy.py

@@ -340,7 +340,7 @@ def __init__(
             init_kwargs["extra_authorize_params"] = extra_params
             init_kwargs["extra_token_params"] = extra_params
 
-        super().__init__(**init_kwargs)
+        super().__init__(**init_kwargs)  # ty: ignore[invalid-argument-type]
 
     def get_oidc_configuration(
         self,

src/fastmcp/server/auth/providers/descope.py

@@ -102,7 +102,7 @@ def __init__(
         )
 
         self.project_id = settings.project_id
-        self.base_url = str(settings.base_url).rstrip("/")
+        self.base_url = AnyHttpUrl(str(settings.base_url).rstrip("/"))
         self.descope_base_url = str(settings.descope_base_url).rstrip("/")
 
         # Create default JWT verifier if none provided

src/fastmcp/server/auth/providers/supabase.py

@@ -107,7 +107,7 @@ def __init__(
         )
 
         self.project_url = str(settings.project_url).rstrip("/")
-        self.base_url = str(settings.base_url).rstrip("/")
+        self.base_url = AnyHttpUrl(str(settings.base_url).rstrip("/"))
 
         # Create default JWT verifier if none provided
         if token_verifier is None: