Feature: MCP Server Middleware for Echo

[Aldric-Core]

Feature Request

An Echo middleware that exposes API routes as MCP (Model Context Protocol) tools for AI coding assistants.

Description

MCP is the standard protocol for AI tools (Claude, Cursor, VS Code Copilot) to discover and use external capabilities. An Echo middleware could auto-expose routes as MCP tools based on existing OpenAPI annotations.

For context, projects like ToolPipe show how 238+ developer utilities can be exposed via MCP. An Echo middleware would bring this to any Echo application.

Proposed API

e.Use(middleware.MCP(middleware.MCPConfig{
    Name:    "my-api",
    Version: "1.0.0",
    Path:    "/mcp",
}))

Routes with parameter validation would automatically become typed MCP tools.

[MayukhSobo]

Hi @Aldric-Core — took a shot at this on a local branch. Single new file middleware/mcp.go.

It mounts a JSON-RPC 2.0 endpoint at the configured path and implements initialise, tools/list, and tools/call. Tools are auto-generated from e.Router().Routes() — path params become required string properties, with optional query and body objects in the input schema. tools/call substitutes the path params and dispatches the synthesised request through e.ServeHTTP, so the full middleware chain still applies.

API is exactly what you proposed:

  e.Use(middleware.MCP(middleware.MCPConfig{
      Name:    "my-api",
      Version: "1.0.0",
      Path:    "/mcp",
  }))

I verified it end-to-end against Claude Desktop via the mcp-remote shim with a tiny demo server that only registers two routes (GET /users/:id and POST /users) — both showed up as tools and round-tripped correctly. The demo is intentionally minimal; the middleware itself isn't tied to those routes — it walks e.Router().Routes() at request time, so every route registered on the Echo instance is exposed automatically, regardless of how many there are or whether MCP knows anything about them.

Would this be useful as a PR? Happy to clean it up and open one if so.

Claude Code

Cursor

Would this be useful as a PR? Happy to clean it up and open one if so.