Add Redis support for the KVStorage protocol

[ruhulio]

Enhancement

Adding Redis support for the KVStorage protocol would allow for scaling MCP instances and more robust data resiliency.

[strawgate]

I'm currently exploring expanding the kv protocol in #1845 and will see how this might fit in

[ruhulio]

I'm currently exploring expanding the kv protocol in #1845 and will see how this might fit in

There is definitely some heavy lifting happening in #1845. I purposefully kept the changes in #1897 simple so that it wouldn't interfere much with any evolution of KVStorage and/or merging with the MCP focused caching you are working through.

[joelacummings]

I also like this idea in terms of replacement type deployments. I wonder if we could add a prefix to namespace these keys to an mcp server? Seems like given the PR here it wouldn't be a lot work and would work well on shared clusters.

[strawgate]

We're currently planning on moving the KV implementations into their own library, will follow-up this week on the plan

[strawgate]

Currently working through the details but see: https://github.com/strawgate/py-kv-store-adapter

If you have other needs here other than what's mentioned in this thread, now is the time to ask

[strawgate]

Would you be open to trying #1913 ?

You should be able to use Redis by adding kv-store-adapter[redis] to your project and providing RedisStore(url="redis://localhost:6379") (or a client directly) to the token_storage

[ruhulio]

Would you be open to trying #1913 ?

You should be able to use Redis by adding kv-store-adapter[redis] to your project and providing RedisStore(url="redis://localhost:6379") (or a client directly) to the token_storage

Sure, I'll give it try later tonight.

[ruhulio]

@strawgate I hit a failure when trying it out.

Here is what I did:

• Replace fastmcp with the switch-kvstore branch:

uv remove fastmcp
uv add git+git@github.com:jlowin/fastmcp.git --branch switch-kvstore

• Use the RedisStore when creating the GitHub provider:

from kv_store_adapter.stores.redis import RedisStore
...
        redis_store = RedisStore(url="redis://localhost:6379")
        provider = GitHubProvider(
            client_id=provider_settings.client_id,
            client_secret=provider_settings.client_secret.get_secret_value(),
            base_url=base_url,
            required_scopes=required_scopes,
            redirect_path=redirect_path,
            client_storage=redis_store,
        )
...

• Start Redis

docker run -p 6379:6379 -it redis:latest

• Start application

[09/24/25 19:18:35] INFO     Initialized GitHub OAuth provider for client <client> with scopes: ['user:email']                                 github.py:279

2025-09-25 00:18:35 [info     ] Starting up server             [<repo>.server.core] root_path=v1/secure server=secure
2025-09-25 00:18:35 [info     ] Registering server for audting [<repo>.audit.core] server=secure
2025-09-25 00:18:35 [info     ] Servers are up and running...  [<repo>.server.core]

• Try to connect and it fails:

Traceback (most recent call last):
  File "/<repo>/.venv/lib/python3.13/site-packages/uvicorn/protocols/http/h11_impl.py", line 403, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        self.scope, self.receive, self.send
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/<repo>/.venv/lib/python3.13/site-packages/uvicorn/middleware/proxy_headers.py", line 60, in __call__
    return await self.app(scope, receive, send)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/applications.py", line 113, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/middleware/errors.py", line 186, in __call__
    raise exc
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/middleware/errors.py", line 164, in __call__
    await self.app(scope, receive, _send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/middleware/authentication.py", line 48, in __call__
    await self.app(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/mcp/server/auth/middleware/auth_context.py", line 48, in __call__
    await self.app(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/middleware/exceptions.py", line 63, in __call__
    await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    raise exc
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/routing.py", line 716, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/routing.py", line 736, in app
    await route.handle(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/routing.py", line 290, in handle
    await self.app(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/middleware/cors.py", line 93, in __call__
    await self.simple_response(scope, receive, send, request_headers=headers)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/middleware/cors.py", line 144, in simple_response
    await self.app(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/routing.py", line 78, in app
    await wrap_app_handling_exceptions(app, request)(scope, receive, send)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    raise exc
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File "/<repo>/.venv/lib/python3.13/site-packages/starlette/routing.py", line 75, in app
    response = await f(request)
               ^^^^^^^^^^^^^^^^
  File "/<repo>/.venv/lib/python3.13/site-packages/mcp/server/auth/handlers/register.py", line 111, in handle
    await self.provider.register_client(client_info)
  File "/<repo>/.venv/lib/python3.13/site-packages/fastmcp/server/auth/oauth_proxy.py", line 428, in register_client
    await self._client_storage_adapter.put(
    ...<3 lines>...
    )
  File "/<repo>/.venv/lib/python3.13/site-packages/kv_store_adapter/adapters/pydantic.py", line 36, in put
    await self.store_protocol.put(collection=collection, key=key, value=value_dict, ttl=ttl)
  File "/<repo>/.venv/lib/python3.13/site-packages/kv_store_adapter/stores/base/managed.py", line 110, in put
    await self.put_entry(collection=collection, key=key, cache_entry=cache_entry, ttl=ttl)
  File "/<repo>/.venv/lib/python3.13/site-packages/kv_store_adapter/stores/redis/store.py", line 99, in put_entry
    json_value: str = cache_entry.to_json()
                      ~~~~~~~~~~~~~~~~~~~^^
  File "/<repo>/.venv/lib/python3.13/site-packages/kv_store_adapter/stores/utils/managed_entry.py", line 33, in to_json
    return dump_to_json(
        obj={
    ...<6 lines>...
        }
    )
  File "/<repo>/.venv/lib/python3.13/site-packages/kv_store_adapter/stores/utils/managed_entry.py", line 64, in dump_to_json
    return json.dumps(obj)
           ~~~~~~~~~~^^^^^
  File "/<user>/.local/share/uv/python/cpython-3.13.5-macos-aarch64-none/lib/python3.13/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
           ~~~~~~~~~~~~~~~~~~~~~~~^^^^^
  File "/<user>/.local/share/uv/python/cpython-3.13.5-macos-aarch64-none/lib/python3.13/json/encoder.py", line 200, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/<user>/.local/share/uv/python/cpython-3.13.5-macos-aarch64-none/lib/python3.13/json/encoder.py", line 261, in iterencode
    return _iterencode(o, 0)
  File "/<user>/.local/share/uv/python/cpython-3.13.5-macos-aarch64-none/lib/python3.13/json/encoder.py", line 180, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
                    f'is not JSON serializable')
TypeError: Object of type AnyUrl is not JSON serializable

• Here is the obj contents that cannot be serialized due to the AnyUrl usage:

{
  "created_at": "2025-09-25T00:23:24.678265+00:00",
  "ttl": "None",
  "expires_at": "None",
  "collection": "oauth-proxy-clients",
  "key": "f1207fad-b83b-4ef3-8f75-afd44d539f0a",
  "value": {
    "redirect_uris": [
      "AnyUrl('http://localhost:6274/oauth/callback')"
    ],
    "token_endpoint_auth_method": "none",
    "grant_types": [
      "authorization_code",
      "refresh_token"
    ],
    "response_types": [
      "code"
    ],
    "scope": "user:email",
    "client_name": "None",
    "client_uri": "None",
    "logo_uri": "None",
    "contacts": "None",
    "tos_uri": "None",
    "policy_uri": "None",
    "jwks_uri": "None",
    "jwks": "None",
    "software_id": "None",
    "software_version": "None",
    "client_id": "f1207fad-b83b-4ef3-8f75-afd44d539f0a",
    "client_secret": "None",
    "client_id_issued_at": "None",
    "client_secret_expires_at": "None",
    "allowed_redirect_uri_patterns": "None"
  }
}

[strawgate]

Oh sorry, yes I had the fix for that on my branch uncommitted. one minute...

[strawgate]

Okay -- pushed the update. Would you be able to try again? also feel free to reply with any issues on the PR