@captchasonic/mcp-server

MCP (Model Context Protocol) server for the CaptchaSonic CAPTCHA solving API. Lets Claude and any MCP-compatible AI agent solve CAPTCHAs, check balance, and verify server health.

Quick Start

claude mcp add sonic --env SONIC_API_KEY=sonic_xxxx -- npx -y @captchasonic/mcp-server

Or install globally:

npm install -g @captchasonic/mcp-server
claude mcp add sonic --env SONIC_API_KEY=sonic_xxxx -- sonic-mcp

Tools

Tool	Description	Requires API Key
health_check	Check if the CaptchaSonic API is healthy	No
get_balance	Get account balance in USD	Yes
solve_captcha	Submit a CAPTCHA image for solving	Yes

solve_captcha

Supports all CaptchaSonic captcha types:

• PopularCaptcha (image grid challenges)
• reCAPTCHA v2 (grid select)
• Geetest (slide, click, nine-grid)
• AWS WAF
• TikTok
• Binance
• OCR (text recognition)
• Turnstile / Cloudflare

Parameters:
  type          — CAPTCHA type (e.g. "PopularCaptchaImage", "geetest_slide", "ocr")
  question      — The challenge question (e.g. "Select all traffic lights")
  image_base64  — Base64-encoded image bytes (PNG/JPEG)
  image_url     — Public URL of the image (alternative to image_base64)
  website_url   — Page URL where the CAPTCHA appears (optional)

Environment Variables

Variable	Description	Default
SONIC_API_KEY	Your CaptchaSonic API key (sonic_xxxx)	— (required)
SONIC_BASE_URL	Override server URL	https://api.captchasonic.com

License

MIT — CaptchaSonic