turn-mcp-web

Turn a single agent request into a durable human-in-the-loop conversation.

turn-mcp-web is a self-hosted MCP server with a browser console. An agent calls turn.wait, execution pauses, a human replies in the web UI, and the same run continues without starting over.

中文文档

Preview

<p align="center"> <img src="./assets/screenshots/live-review-session.png" alt="Live review session" width="100%"> </p>

<p align="center"> <img src="./assets/screenshots/settings-overview.png" alt="Settings overview" width="32%"> <img src="./assets/screenshots/setup-snippets.png" alt="Client setup snippets" width="32%"> <img src="./assets/screenshots/language-picker.png" alt="First launch language picker" width="32%"> </p>

Why It Exists

Most agent integrations treat a human checkpoint as a dead end:

• the model asks a question
• the run stops
• the next message starts a new run with partial context

turn-mcp-web keeps that checkpoint inside the same execution loop.

work -> turn.wait -> human reply -> work -> turn.wait -> human reply

That makes it useful for approvals, branching decisions, operator handoffs, review queues, and long-running assisted workflows.

What You Get

• MCP tool aliases: turn.wait, turn_wait, turn
• browser console for live replies
• Streamable HTTP transport for IDE MCP clients
• stdio entrypoint for desktop clients that spawn MCP servers
• REST long-poll API for Python and non-MCP agent frameworks
• persistent history and event logging
• webhook and Telegram notifications
• operator and viewer API roles
• session list, quick replies, timeout controls, and live SSE updates
• one-command local startup

Quick Start

macOS

Double-click start.command

Windows

Double-click start.bat

Linux

bash start.sh

From Source

npm install
npm run build
npm start

Web console: http://127.0.0.1:3737/
MCP endpoint: http://127.0.0.1:3737/mcp

Core Workflow

1. Start the server.
2. Connect your MCP client to http://127.0.0.1:3737/mcp or launch the stdio entrypoint.
3. Give the agent skills/turn-mcp-web/SKILL.md so it routes user-facing checkpoints through turn.wait.
4. When the agent pauses, answer in the browser console.
5. The same agent run resumes with your reply.

Client Setup

Streamable HTTP

Use this for Cursor, Windsurf, VS Code, Claude Code, Antigravity, and other MCP clients that support remote HTTP servers.

{
  "mcpServers": {
    "turn-mcp-web": {
      "url": "http://127.0.0.1:3737/mcp"
    }
  }
}

Windsurf uses serverUrl instead of url.

stdio

Use this when the client launches MCP servers as local child processes.

{
  "mcpServers": {
    "turn-mcp-web": {
      "command": "node",
      "args": ["/absolute/path/to/dist/server-stdio.js"]
    }
  }
}

The stdio process still opens the same web console on port 3737.

Python

Use the bundled Python client when your framework does not speak MCP directly.

pip install ./python-client

from turn_mcp_client import TurnMcpClient, TurnMcpCanceled, TurnMcpTimeout

client = TurnMcpClient("http://127.0.0.1:3737")

try:
    reply = client.wait(
        context="About to apply a production migration.",
        question="Should I proceed?",
        options=["Proceed", "Show SQL", "Cancel"],
        agent_name="MigrationAgent",
    )
    print(reply)
except TurnMcpTimeout:
    print("No reply before timeout.")
except TurnMcpCanceled:
    print("Canceled by operator.")

More examples: python-client/README.md

Agent Contract

Give the agent one of these files:

• Skill entry: skills/turn-mcp-web/SKILL.md
• 中文参考: skills/turn-mcp-web/references/skill.zh-CN.md

Those files tell the agent to use turn.wait as the communication boundary instead of replying directly.

API

Public

• GET /healthz
• GET /api/public-config

Session and wait control

• GET /api/waits
• GET /api/waits/:id
• POST /api/waits/:id/respond
• POST /api/waits/:id/cancel
• POST /api/waits/:id/extend
• POST /api/waits/cancel-all
• POST /api/waits/create-and-wait

History and events

• GET /api/history
• GET /api/history/timeline
• GET /api/events
• GET /api/stream

Runtime management

• GET /api/auth-check
• GET /api/sessions
• POST /api/settings
• POST /api/auto-configure
• POST /api/auto-unconfigure

Environment

Variable	Default	Purpose
TURN_MCP_HTTP_HOST	127.0.0.1	HTTP bind host
TURN_MCP_HTTP_PORT	3737	HTTP bind port
TURN_MCP_HTTP_PATH	/mcp	MCP endpoint path
TURN_MCP_DEFAULT_TIMEOUT_SECONDS	600	Default wait timeout
TURN_MCP_API_KEY	unset	Operator key
TURN_MCP_VIEWER_API_KEY	unset	Viewer key
TURN_MCP_REQUIRE_API_KEY	auto	Enable auth
TURN_MCP_EVENT_LOG_FILE	unset	JSONL event log path
TURN_MCP_HISTORY_FILE	unset	JSONL history path
TURN_MCP_WEBHOOK_URL	unset	Outbound webhook target
TURN_MCP_WEBHOOK_EVENTS	unset	Comma-separated webhook events
TURN_MCP_WEBHOOK_SECRET	unset	HMAC signing secret
TURN_MCP_WEBHOOK_FORMAT	json	json, slack, or discord
TURN_MCP_TELEGRAM_BOT_TOKEN	unset	Telegram bot token
TURN_MCP_TELEGRAM_CHAT_ID	unset	Telegram target chat
TURN_MCP_TELEGRAM_EVENTS	wait_created	Telegram event filter
TURN_MCP_RATE_LIMIT_MAX	120	Requests per IP
TURN_MCP_RATE_LIMIT_WINDOW_SECONDS	60	Rate limit window
TURN_MCP_MAX_CONCURRENT_WAITS_PER_SESSION	10	Per-session concurrency cap
TURN_MCP_REINFORCEMENT_SUFFIX	built-in	Appended reminder text

Authentication

Auth is off by default. When enabled, send either of these headers:

x-turn-mcp-api-key: <key>
Authorization: Bearer <key>

Roles:

• operator: full control
• viewer: read-only inspection and SSE subscription

Docker

docker build -t turn-mcp-web .
docker run --rm -p 3737:3737 \
  -e TURN_MCP_HTTP_HOST=0.0.0.0 \
  -e TURN_MCP_API_KEY=your_key \
  turn-mcp-web

Compose file: docker-compose.yml

Repository Layout

src/            TypeScript server
public/         Browser console
python-client/  Python client package
assets/         README screenshots and demo video

Contributing

See CONTRIBUTING.md.

License

MIT