Merge pull request #405 from jlowin/sse-path

Fix bug that sets message path and sse path to same value

src/fastmcp/server/server.py

@@ -869,7 +869,7 @@ class FastMCP(Generic[LifespanResultT]):
         elif transport == "sse":
             return create_sse_app(
                 server=self,
-                message_path=path or self.settings.message_path,
+                message_path=self.settings.message_path,
                 sse_path=path or self.settings.sse_path,
                 auth_server_provider=self._auth_server_provider,
                 auth_settings=self.settings.auth,

src/fastmcp/utilities/tests.py

@@ -71,7 +71,7 @@ def _run_server(mcp_server: FastMCP, transport: Literal["sse"], port: int) -> No
 
 @contextmanager
 def run_server_in_process(
-    server_fn: Callable[[str, int], None],
+    server_fn: Callable[[str, int], None], *args
 ) -> Generator[str, None, None]:
     """
     Context manager that runs a Starlette app in a separate process and returns the
@@ -88,7 +88,9 @@ def run_server_in_process(
         s.bind((host, 0))
         port = s.getsockname()[1]
 
-    proc = multiprocessing.Process(target=server_fn, args=(host, port), daemon=True)
+    proc = multiprocessing.Process(
+        target=server_fn, args=(host, port, *args), daemon=True
+    )
     proc.start()
 
     # Wait for server to be running

tests/client/test_sse.py

@@ -56,9 +56,9 @@ def fastmcp_server():
     return server
 
 
-def run_server(host: str, port: int) -> None:
+def run_server(host: str, port: int, path: str | None = None) -> None:
     try:
-        app = fastmcp_server().http_app(transport="sse")
+        app = fastmcp_server().http_app(transport="sse", path=path)
         server = uvicorn.Server(
             config=uvicorn.Config(app=app, host=host, port=port, log_level="error")
         )
@@ -109,6 +109,13 @@ def run_nested_server(host: str, port: int) -> None:
     sys.exit(0)
 
 
+async def test_run_server_on_path():
+    with run_server_in_process(run_server, "/help") as url:
+        async with Client(transport=SSETransport(f"{url}/help")) as client:
+            result = await client.ping()
+            assert result is True
+
+
 async def test_nested_sse_server_resolves_correctly():
     # tests patch for
     # https://github.com/modelcontextprotocol/python-sdk/pull/659