mcp-server

Stateless MCP 2026-07-28 Streamable HTTP server on Bun and Hono. This process is a protocol router: it validates the wire protocol, delegates to enrolled domain modules, and returns JSON. It does not authenticate callers and does not ship a domain module yet.

Caller login is the consumer's job (Cursor, a backend, a gateway). This process only enforces Host/Origin allowlists.

Run

bun install
cp .env.example .env
bun run dev

Production:

bun run start

Typecheck and tests:

bun run typecheck
bun test

Related MCP server: nitro-mcp-server

Docker

docker compose up --build

Compose binds HOST=0.0.0.0 and sets MCP_ALLOWED_HOSTS=localhost,127.0.0.1. Add a public hostname to that list before serving beyond loopback.

Sentry

Optional. Leave SENTRY_DSN unset or empty and the process starts without Sentry. Set a DSN to enable error reporting and traces (SENTRY_TRACES_SAMPLE_RATE, default 0.1). SENTRY_ENVIRONMENT defaults to production. SENTRY_RELEASE defaults to the package.json version.

Enroll a module

See src/modules/README.md. Add a folder that implements DomainModule, then append it to the array in src/modules/index.ts. Domain secrets stay in that module's own env — do not add them to the platform schema.

A later FPL module uses the operator credentials documented in src/docs/fpl-authentication.md.

Sample tools/list

curl -sS -X POST http://127.0.0.1:3000/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/list' \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/list",
    "params": {
      "_meta": {
        "io.modelcontextprotocol/protocolVersion": "2026-07-28",
        "io.modelcontextprotocol/clientInfo": { "name": "curl", "version": "0.0.0" },
        "io.modelcontextprotocol/clientCapabilities": {}
      }
    }
  }'

GET and DELETE /mcp return 405 with Allow: POST.

Cursor

Point Cursor at the running HTTP endpoint in .cursor/mcp.json or ~/.cursor/mcp.json. Cursor is the client here; env for this process lives in .env or Compose, not in mcp.json.

{
    "mcpServers": {
        "mcp-server": {
            "url": "http://127.0.0.1:3000/mcp"
        }
    }
}

If you later launch this process from Cursor over stdio instead, put platform env in that server's env block.