mcp-a2a-gateway

[](https://www.npmjs.com/package/truss-mcp-a2a-gateway) [](https://opensource.org/licenses/MIT)

Bridge any MCP server to Google's A2A (Agent-to-Agent) protocol. Expose MCP tools as A2A-compatible agent skills, enabling discovery and invocation by any A2A client -- LangGraph, CrewAI, Google ADK, AutoGen, and every A2A-compliant framework.

[A2A Client] <──HTTP/JSON-RPC──> [Gateway] <──MCP Protocol──> [MCP Server]
                                    │
                              /.well-known/agent.json  (auto-generated)
                              POST /                   (JSON-RPC: message/send, tasks/get, tasks/cancel)
                              POST /stream             (SSE streaming)
                              GET  /health             (health check)

MCP tools are powerful but locked into the MCP ecosystem. The A2A protocol is Google's open standard for agent interoperability with 50+ technology partners. This gateway bridges the two -- install it, point it at any MCP server, and it becomes an A2A agent with zero code changes.

• Auto-generated Agent Cards -- Reads your MCP server's tool list and generates a compliant /.well-known/agent.json
• Full A2A task lifecycle -- submitted -> working -> completed/failed/canceled
• JSON-RPC endpoint -- message/send, tasks/get, tasks/cancel per A2A spec
• SSE streaming -- Real-time task updates via message/stream
• Stdio + SSE transports -- Connect to any MCP server via subprocess or HTTP
• Intelligent tool routing -- Structured, skill-based, JSON-in-text, name-matching, and single-tool shortcut
• Zero code changes -- Your MCP server stays unchanged

Run with npx (no install needed):

npx -y truss-mcp-a2a-gateway