LocalFree

Captcha MCP server

zekebuilds-lab/captcha-mcp

Middleware that gates MCP tool calls behind a Hashcash proof-of-work challenge or an L402 Lightning payment via self-hosted LNbits.

1 GitHub stars
Source code Website

Install Captcha in Claude Code

Claude Code
claude mcp add captcha -- npx -y @powforge/captcha-mcp
mcp.json (Claude Desktop, Cursor, VS Code, Windsurf)
{
  "mcpServers": {
    "captcha": {
      "command": "npx",
      "args": [
        "-y",
        "@powforge/captcha-mcp"
      ]
    }
  }
}

Frequently asked questions

What does the Captcha MCP server do?

Middleware that gates MCP tool calls behind a Hashcash proof-of-work challenge or an L402 Lightning payment via self-hosted LNbits.

Is the Captcha MCP server free?

Yes, most likely. Open source and no paid account or API key is mentioned in the listing. Check the provider for current pricing.

Does Captcha run locally or remotely?

Local. Runs on your machine (stdio). You install it with npx, uvx, Docker or from source.

How do I add Captcha to Claude Code?

Run: claude mcp add captcha -- npx -y @powforge/captcha-mcp

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