Support MCP Protocol v2025-03-26 #9
Description
Background
Remote‑MCP currently implements the MCP wire‑protocol over a stateful stdio transport (via StdioServerTransport) and batches requests using tRPC’s HTTP batch link. As of the 2025‑03‑26 MCP specification, the protocol has moved to a fully stateless HTTP request/response transport, with version negotiation, per‑method endpoints, and JSON‑RPC‑style request/response bodies.
Problem
When attempting to connect to an MCP server using protocol version 2025-03-26, clients receive errors because:
- We still instantiate
StdioServerTransportinstead of the new HTTP transport. - tRPC’s batched
/mcpendpoint does not match the spec’s per‑method HTTP routes. - No protocol version header or handshake is performed.
- Request/response payloads do not conform to the updated JSON schemas.
References
- MCP Spec (2025‑03‑26): https://github.com/modelcontextprotocol/specification/tree/2025-03-26
- Current client implementation:
packages/client/src/client.ts - tRPC setup:
packages/server/src/index.ts