capmonster-mcp

capmonster-mcp (TypeScript)

MCP server for solving captchas via CapMonster Cloud, published to npm. This is a TypeScript port of the Python implementation in the repo root — same tools, same behavior. It is the solve brain: it lists supported captcha types, serves CapMonster's docs, and creates/polls solve tasks against the CapMonster Cloud REST API. It has no browser of its own — pair it with a browser-driving MCP (e.g. capmonster-mcp-patchright) that does the page work (navigation, interaction, reading the live DOM/network, and injecting the solved token back into the page).

Quick start

{
  "mcpServers": {
    "capmonster": {
      "command": "npx",
      "args": ["-y", "capmonster-mcp"],
      "env": { "CM_API_KEY": "YOUR_API_KEY" }
    }
  }
}

npx runs the published npm package with no local clone needed.

Configuration

This server only runs over stdio (the transport MCP clients use to launch it as a subprocess), so there are no HTTP headers to carry a per-request key — set CM_API_KEY in the client's env block and every tool call in that session uses it.

Tools

• get_supported_tasks — list captcha task types CapMonster supports (from the live OpenAPI spec).
• get_task_parameters(task_type) — required/optional fields, variant notes, and the solution schema for a task type.
• get_docs(url, offset, limit, section) — fetch a CapMonster doc page (docs.capmonster.cloud/api.capmonster.cloud only), with section-jump and pagination.
• create_task(task) — submit a captcha task, returns a taskId.
• get_task_result(task_id) — poll a task once.
• get_task_result_wait(task_id, timeout_seconds, poll_interval_seconds) — poll a task to completion (preferred over driving the loop yourself).
• get_actual_user_agent() — fetch a current Windows User-Agent to use as one consistent fingerprint across the browser and the solve task.
• get_balance() — CapMonster account balance.

Workflow

See ../capmonster_agent/SKILL.md for the step-by-step procedure for analyzing a captcha-protected page and solving it with this server paired with a patchright (or any stateful browser-automation) MCP.

Development

npm install
npm run build
npm test

• npm run dev — run the server directly with tsx (no build step).
• npm run typecheck — tsc --noEmit.
• npm run lint — Biome lint.