Co-authored-by: David Soria Parra <davidsp@anthropic.com>
Co-authored-by: Basil Hosmer <basil@anthropic.com>
Co-authored-by: ihrpr <inna@anthropic.com>
* Option to mount SSE server to existing ASGI server
Fixes#311
Add option to mount SSE server to an existing ASGI server.
* Add a new method `sse_app` in `src/mcp/server/fastmcp/server.py` to return an instance of the SSE server app.
* Update the `run_sse_async` method in `src/mcp/server/fastmcp/server.py` to use the new `sse_app` method.
* Update the documentation in `README.md` to include instructions on how to mount the SSE server to an existing ASGI server.
* Fix the example in `README.md` to use `app.mount('/', mcp.sse_app())` instead.
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For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/modelcontextprotocol/python-sdk/issues/311?shareId=XXXX-XXXX-XXXX-XXXX).
* Add `sse_app` method and update `run_sse_async` method in `server.py`
* Add `sse_app` method to return an instance of the SSE server app
* Update `run_sse_async` method to use the new `sse_app` method
Update `README.md` to include instructions for mounting SSE server
* Add section on mounting the SSE server to an existing ASGI server
* fix: Move import statements to the top of the file/
* docs: Update README to reflect changes in mounting SSE server with Starlette
* docs: Formatting of SSE server mounting example in README
* feat: allow lowlevel servers to return a list of resources
The resource/read message in MCP allows of multiple resources
to be returned. However, in the SDK we do not allow this. This
change is such that we allow returning multiple resource in
the lowlevel API if needed. However in FastMCP we stick to
one, since a FastMCP resource defines the mime_type in the decorator
and hence a resource cannot dynamically return different mime_typed resources.
It also is just the better default to only return one resource.
However in the lowlevel API we will allow this.
Strictly speaking this is not a BC break since the new return value
is additive, but if people subclassed server, it will break them.
* feat: lower the type requriements for call_tool to Iterable
- Add proper generic parameter for lifespan context type
- Update README with TypedDict example for strong typing
- Fix context variable initialization in server
- Improve property return type safety
- Remove redundant documentation
- Ensure compatibility with existing tests
Adds support for the lifespan API to FastMCP server, enabling:
- Simple setup with FastMCP constructor
- Type-safe context passing to tools and handlers
- Configuration via Settings class
Introduce ReadResourceContents type to properly handle MIME types in resource responses. Breaking change in FastMCP read_resource() return type.
Github-Issue:#152
The server was ignoring mime types set on resources, defaulting to text/plain
for strings and application/octet-stream for bytes. Now properly preserves
the specified mime type in both FastMCP and low-level server implementations.
Note that this is breaks backwards compatibility as it changes the return
values of read_resource() on FastMCP. It is BC compatible on lowlevel since
it only extends the callback.
Github-Issue: #152
Reported-by: eiseleMichael
