Writ Cloud

Your saved browser workflows, as tools your assistant can call.

Quick start · Tools · Configuration · Security · Troubleshooting · Contributing

writ-mcp connects a stdio MCP client — Claude Code, Claude Desktop, Cursor, Windsurf, Codex — to Writ, so the browser workflows you already recorded become tools your assistant can call: run them, read the data they collected, search past results, schedule them, expose them as REST endpoints, and kick off site crawls.

It is a transparent stdio↔HTTP proxy and nothing else. Every tool, schema and rule lives server-side, so what you get always matches what your instance can do — and a new tool never requires upgrading this package. Zero dependencies, one file, Node core only.

Clients that speak Streamable HTTP natively don't need this at all — point them straight at the /mcp endpoint with an Authorization: Bearer <key> header.

Quick start

1. Get an API key. In the Writ app: Settings → Developers → API keys. Keys look like wt_….

2. Add the server.

Against a self-hosted coordinator:

claude mcp add writ-selfhost -e WRIT_API_KEY=<YOUR_API_KEY> -- npx -y writ-mcp --url https://writ.example.com

Against a coordinator on this machine:

claude mcp add writ-selfhost -e WRIT_API_KEY=<YOUR_API_KEY> -- npx -y writ-mcp --url http://localhost:8000

Against a published per-workflow endpoint (an "Expose as MCP" slug URL is used verbatim — no path rewriting):

claude mcp add my-tools -e WRIT_API_KEY=<YOUR_API_KEY> -- npx -y writ-mcp --url https://mcp.example.com/mcp/my-tools

3. Check it.

claude mcp list

Writ Cloud is the default target when you pass no --url (https://api.usewrit.app). Pass --url to point the connector at your own coordinator instead. See Status.

Pass the key through the environment, not the command line. --api-key works, but it puts your key in the process's argument list where any local process can read it via ps, and your shell records it in history. The connector prints a note when you use it.

Your running coordinator also hands out these one-liners, pre-filled, on its Connect page and at GET /api/mcp/connect-info:

Claude Desktop / Cursor (config file)

Add to claude_desktop_config.json (Claude Desktop) or ~/.cursor/mcp.json (Cursor). The env form is recommended — it keeps the key out of the argument list:

{
  "mcpServers": {
    "writ-selfhost": {
      "command": "npx",
      "args": ["-y", "writ-mcp"],
      "env": {
        "WRIT_COORDINATOR_URL": "https://writ.example.com",
        "WRIT_API_KEY": "<YOUR_API_KEY>"
      }
    }
  }
}

Without npm

A self-host install bundles this connector at connectors/writ-mcp. There is no build step, so you can run it straight from disk:

node /path/to/writ/connectors/writ-mcp/index.js --url https://writ.example.com

It coexists with the other Writ servers. Each surface registers under its own slug on purpose — the desktop app is writ, Writ Cloud is writ-cloud, a self-hosted coordinator is writ-selfhost — and each identifies itself to the assistant with a distinct title. Keep any combination connected at once.

Tools you get

Served by the server you connect to, not by this package, so a new server tool reaches you without a connector update. Writ Cloud lists the 39 tools below; a self-hosted coordinator lists the ones marked in its column.

The build tools (writ_browser_use, writ_record_website, writ_website_to_api, then writ_browser_act / _context / _network / _save / _cancel) are on both targets; neither has a writ_build tool, so use writ_record_website. Your assistant opens a real browser, drives it turn by turn, and saves the session as a reusable workflow that afterwards replays with no model in the loop. Writ Cloud runs it on Writ's fleet; a self-hosted coordinator runs it on your own fleet agent. Either way your assistant is the brain — no second model key is involved.

Reusing a recent result (max_age)

Running a workflow drives a real browser, so asking the same question twice in one session costs two full runs and two waits. Every workflow tool takes an optional max_age (seconds) meaning a recent answer is good enough:

{ "name": "run_price_check", "arguments": { "sku": "B0C123", "max_age": 300 } }

• omitted or 0 — always run fresh (the default; nothing goes stale on its own).
• N — reuse a result younger than N seconds, otherwise run.

A reused answer carries _cache: {hit: true, age_seconds: N} so the assistant can tell how current it is.