MCP

Exposes a devframe's agent host as a Model Context Protocol server: agents call flagged RPCs and read resources.

import { createMcpServer } from 'devframe/adapters/mcp'
import devframe from './devframe'

await createMcpServer(devframe, { transport: 'stdio' })

@modelcontextprotocol/server is a peer dependency; createMcpServer speaks stdio, spawned per session.

Route-based server

The dev server exposes the same surface over HTTP, live. Enable with cli.mcp:

import { defineDevframe } from 'devframe'

export default defineDevframe({
  // …
  cli: {
    mcp: true,
  },
})

The endpoint speaks Streamable-HTTP at /__mcp (/__<id>/__mcp under a host), sharing its origin/port. --mcp / --no-mcp override; __connection.json advertises it.

Each session gets its own MCP server, keyed by Mcp-Session-Id. An origin gate requires Origin be loopback (or allow-listed) and rejects Origin-less requests. Widen for a tunnel/LAN origin with cli: { mcp: { allowedOrigins: ['https://tunnel.example.com'] } }.

Hosted bridges

Both bridges forward it to their side-car dev server, advertising the endpoint in __connection.json:

// Vite (@devframes/vite)
devframeViteBridge(devframe, { mcp: true })

// Next.js (@devframes/next)
createDevframeNextHandler(devframe, { mcp: true })

Custom hosts

createMcpFetchHandler(ctx, options) returns the endpoint as a Request → Response handler plus a dispose() — mount on any fetch server.

import { createMcpFetchHandler } from 'devframe/adapters/mcp'

const mcp = createMcpFetchHandler(ctx, {
  serverName: 'my-tool (devframe)',
  serverVersion: '1.0.0',
  exposeSharedState: true,
})
// route every method on /__mcp to mcp.fetch(request)

Discovery: devframe connect

The devframe bin ships an MCP connector (next-devtools-mcp-style) that finds every running devframe. Configure once:

{
  "mcpServers": {
    "devframe": { "command": "npx", "args": ["devframe", "connect"] }
  }
}

Two gateway tools (devframe:connect:* ids — see tool ids and wire names):

• devframe_connect_list-instances — list running dev servers and their MCP tools.
• devframe_connect_call-tool — invoke one tool on an instance ({ port, tool, args }) over Streamable-HTTP.

Discovery reads the instance registry: every createDevServer writes ~/.devframe/instances/<pid>-<port>.json, dialed with a loopback origin. In-process hosts register via registerDevframeInstance (devframe/node). --port <n> probes a port; DEVFRAME_INSTANCES_DIR relocates the registry, DEVFRAME_DISABLE_INSTANCE_REGISTRY=1 opts out.

See Agent-Native for the API and safety model.