Expose streamablehttp_client session id callback to users #2485
Description
Enhancement
Currently, the StreamableHTTPTransport doesn't expose the session id callback from MCP's streamablehttp_client.
async with streamablehttp_client(
self.url,
auth=self.auth,
**client_kwargs,
) as transport:
read_stream, write_stream, _ = transport
async with ClientSession(
read_stream, write_stream, **session_kwargs
) as session:
yield sessionFor users wanting to manage some state on the client side related to sessions, it is more complicated to access mcp-session-id without working with lower level code.
Proposal:
async with streamablehttp_client(
self.url,
auth=self.auth,
**client_kwargs,
) as transport:
# _ is replaced with get_session_id and attached to the transport
read_stream, write_stream, get_session_id = transport
self.get_session_id_cb = get_session_id
async with ClientSession(
read_stream, write_stream, **session_kwargs
) as session:
yield session
def get_session_id(self) -> str | None:
if self.get_session_id_cb:
return self.get_session_id_cb()
return None