The HTTP+SSE transport was superseded by Streamable HTTP in the 2025-03-26
spec revision and is formally deprecated under SEP-2596. Mark every public
entry point with typing_extensions.deprecated so type checkers flag it and a
runtime MCPDeprecationWarning fires: sse_client, SseServerParameters,
SseServerTransport, MCPServer.sse_app / run_sse_async, and the
run(transport="sse") overload. Nested constructions suppress the inner
warning so callers see exactly one.
Also: mcp run --transport help text drops sse, python -m mcp.client
connects with Streamable HTTP, and the url_elicitation client snippet
moves to Streamable HTTP. Docs and migration guide updated.
No-Verification-Needed: user requested immediate push, verification explicitly waived
Max Isbey
f0e6057a19