zekebuilds-lab/captcha-mcp

Overview

A Model Context Protocol (MCP) server that authenticates AI agents using Proof of Work and Lightning Network payments. It charges agents per API call without requiring traditional accounts. Implemented in JavaScript as an npm package.

Best for

Best for
Developers building monetized agent APIs or wanting accountless authentication

Use cases

• Authenticate AI agents in MCP-compatible applications
• Implement pay-per-call billing for agent APIs
• Add abuse protection via PoW challenges

How to use

Install

npx -y @powforge/captcha-mcp

Tested with

Claude Code, Cursor, ChatGPT

Example client config

{\n  "mcpServers": {\n    "powforge-captcha": {\n      "command": "npx",\n      "args": ["-y", "@powforge/captcha-mcp"]\n    }\n  }\n}

Notes

A Model Context Protocol (MCP) server that authenticates AI agents using Proof of Work and Lightning Network payments. It charges agents per API call without requiring traditional accounts. Implemented in JavaScript as an npm package.

0 stars on GitHub. Last updated 2026-05-14. Licensed MIT.

Use cases

• Authenticate AI agents in MCP-compatible applications
• Implement pay-per-call billing for agent APIs
• Add abuse protection via PoW challenges

Pros

• No account registration needed
• Built-in microtransactions via Lightning Network
• Open-source and easy to integrate

Cons

• Early stage with no community adoption
• Requires Lightning Network infrastructure
• PoW increases response latency

Indexed from awesome-mcp-servers-punkpeye and enriched against its public facts.