Mcp Http Post

Handle MCP JSON-RPC requests via HTTP Streamable transport.

This endpoint implements the MCP Streamable HTTP transport (spec 2025-03-26).

• Accepts JSON-RPC requests via POST
• Returns either immediate JSON response OR SSE stream on same connection
• Session management via Mcp-Session-Id header
• Content negotiation via Accept header

The response format is determined by:

1. Message type (notifications return 202 Accepted)
2. Accept header (must include text/event-stream for SSE)
3. Tool execution characteristics (long-running tools may stream)

Args: request: FastAPI request message: JSON-RPC message auth_api_key: API key authentication mcp_session_id: Optional session ID from header mcp_protocol_version: MCP-Protocol-Version header (defaults to 2025-03-26 if absent) accept: Accept header for content negotiation

Returns: JSONResponse with immediate result OR EventSourceResponse with SSE stream