2Captcha MCP

2Captcha MCP

MCP server exposing the full 2Captcha API surface — 31 captcha types, 5 management tools, 3 pingback CRUD tools, 3 webhook event-store tools, and 1 composite solve-and-wait tool (43 tools total) — to Claude Code via stdio.

Built on the official 2captcha-python SDK (AsyncTwoCaptcha), so retry/polling/parsing are handled upstream and every captcha type the SDK supports is available the moment the SDK adds it.

Quick start

pip install twocaptcha-mcp
# or for development:
pip install -e ".[dev]"

Create a .env next to the project root:

2Captcha_API_KEY=your_2captcha_key_here

Verify it works:

python -m twocaptcha_mcp           # starts the stdio server (Ctrl+C to stop)

Register the server with Claude Code:

claude mcp add 2captcha -e 2Captcha_API_KEY=your_2captcha_key_here -- python -m twocaptcha_mcp

After a claude restart, prompt the model with:

"Use twocaptcha_balance to check my account."

Configuration

All settings are environment-driven. Aliases in priority order:

Setting	Aliases	Default	Range
API key (required)	2Captcha_API_KEY, TWOCAPTCHA_API_KEY, 2CAPTCHA_API_KEY, API_KEY_2CAPTCHA	—	—
Server	TWOCAPTCHA_SERVER	2captcha.com	2captcha.com, rucaptcha.com
Default timeout	TWOCAPTCHA_DEFAULT_TIMEOUT	120 s	1..600
reCAPTCHA timeout	TWOCAPTCHA_RECAPTCHA_TIMEOUT	600 s	1..1200
Polling interval	TWOCAPTCHA_POLLING_INTERVAL	10 s	1..120
Soft id	TWOCAPTCHA_SOFT_ID	4580	—
Log level	TWOCAPTCHA_LOG_LEVEL	INFO	DEBUG/INFO/WARNING/ERROR/CRITICAL
Default pingback URL	TWOCAPTCHA_DEFAULT_CALLBACK	unset	https URL

Tools

Captcha solvers (31)

Tool	SDK method	Required arguments
twocaptcha_solve_normal	normal	file_path xor file_base64
twocaptcha_solve_text	text	text
twocaptcha_solve_audio	audio	file (xor), audio_lang
twocaptcha_solve_grid	grid	file (xor)
twocaptcha_solve_canvas	canvas	file (xor)
twocaptcha_solve_coordinates	coordinates	file (xor)
twocaptcha_solve_rotate	rotate	files: list
twocaptcha_solve_vkimage	vkimage	files, steps
twocaptcha_solve_recaptcha	recaptcha	sitekey, url, version, enterprise
twocaptcha_solve_hcaptcha	hcaptcha	sitekey, url
twocaptcha_solve_turnstile	turnstile	sitekey, url (+ data/pagedata for CF Challenge)
twocaptcha_solve_funcaptcha	funcaptcha	sitekey, url
twocaptcha_solve_geetest	geetest	gt, challenge, url
twocaptcha_solve_geetest_v4	geetest_v4	captcha_id, url
twocaptcha_solve_capy	capy	sitekey, url
twocaptcha_solve_keycaptcha	keycaptcha	s_s_c_user_id, s_s_c_session_id, two signs, url
twocaptcha_solve_lemin	lemin	captcha_id, div_id, url
twocaptcha_solve_mtcaptcha	mtcaptcha	sitekey, url
twocaptcha_solve_friendly_captcha	friendly_captcha	sitekey, url
twocaptcha_solve_cutcaptcha	cutcaptcha	misery_key, apikey, url
twocaptcha_solve_amazon_waf	amazon_waf	sitekey, iv, context, url
twocaptcha_solve_tencent	tencent	app_id, url
twocaptcha_solve_atb_captcha	atb_captcha	app_id, api_server, url
twocaptcha_solve_datadome ⚑	datadome	proxy, user_agent, captcha_url, pageurl
twocaptcha_solve_captchafox ⚑	captchafox	proxy, user_agent, sitekey, pageurl
twocaptcha_solve_vkcaptcha ⚑	vkcaptcha	proxy, user_agent, redirect_uri
twocaptcha_solve_prosopo	prosopo	sitekey, pageurl
twocaptcha_solve_temu	temu	body, part1..3
twocaptcha_solve_altcha	altcha	pageurl
twocaptcha_solve_cybersiara	cybersiara	master_url_id, pageurl, cyber_user_agent
twocaptcha_solve_yandex_smart	yandex_smart	sitekey, url

⚑ — proxy and user_agent are required by the SDK signature.

All solver tools accept the same set of optional kwargs (mixin SolverKwargs):

• proxy: {type, uri} (HTTP/HTTPS/SOCKS4/SOCKS5)
• pingback: HttpUrl — per-call pingback URL (must be pre-registered)
• soft_id: int
• cookies: str
• user_agent: str
• lang: str
• header_acao: 0|1

Management (5)

• twocaptcha_balance — current balance in USD
• twocaptcha_report_good / twocaptcha_report_bad — report a captcha id within 15 minutes
• twocaptcha_get_result — poll a captcha id manually (paired with send_raw)
• twocaptcha_send_raw — escape hatch for SDK methods this server does not yet expose

Pingback CRUD (3)

• twocaptcha_register_pingback — whitelist a callback URL
• twocaptcha_list_pingbacks — list whitelisted addresses
• twocaptcha_delete_pingback — delete one or addr="all"

Development

pytest --cov=twocaptcha_mcp --cov-branch --cov-fail-under=92 -v
ruff check . && ruff format --check .
mypy --strict twocaptcha_mcp

Run live tests against the real 2Captcha API (consumes credits):

pytest -m live --run-live          # balance + solve_normal + concurrent_balance
pytest -m e2e --run-e2e             # full MCP protocol roundtrip via mcp.client.session

Architecture

twocaptcha_mcp/
├── __main__.py            # stdio entrypoint
├── server.py              # build_server + dispatch_tool_call
├── config.py              # pydantic-settings (.env)
├── logger.py              # stderr-only logger (stdout is reserved for stdio MCP)
├── client/
│   ├── solver.py          # SolverClient — async wrapper over AsyncTwoCaptcha
│   ├── pingback.py        # httpx wrapper for legacy res.php
│   ├── rate_limiter.py    # async sliding-window per-method rate limiter
│   └── errors.py          # internal CaptchaError hierarchy
├── schemas/               # Pydantic request/response models per captcha family
├── tools/                 # @captcha_tool handlers per captcha family + composite
└── webhook_receiver/      # Starlette app + SQLite store (twocaptcha-mcp-webhook)

Tool handlers depend only on the SolverClient / PingbackClient abstractions — the SDK is never imported from a handler. Adding a new captcha type is a 3-step process: schema → tool handler → snapshot test count bump.

Webhook receiver (optional, since 0.3.0)

For long-running solves (recaptcha v3 up to 600 s), the polling-mode SDK call holds the MCP request slot for the entire duration. Run the optional twocaptcha-mcp-webhook server to flip into pingback mode — 2Captcha POSTs the result to your URL, the receiver writes it to SQLite, and the MCP tools read asynchronously without blocking.

• Composite tool: twocaptcha_solve_and_wait_pingback sends the captcha and waits on the local store
• Read tools: twocaptcha_pingback_events_list/get/clear
• Deployment: docs/DEPLOY-WEBHOOK.md
• Troubleshooting: TROUBLESHOOTING.md

Contributing

See CONTRIBUTING.md for the dev loop, code conventions, and the SemVer policy for the MCP tool surface.

Security

See SECURITY.md. Vulnerabilities are reported privately via GitHub Security Advisory.

License

MIT — see LICENSE.

---

_{Registry verification — mcp-name: io.github.aruxojuyu665/twocaptcha-mcp}