What is captcha-mcp?
captcha-mcp is a MCP server by zekebuilds-lab that middleware that gates MCP tool calls behind a Hashcash proof-of-work challenge or an L402 Lightning payment via self-hosted LNbits. It is listed under Security and has 1 GitHub stars.
| Type | Mcp server |
|---|---|
| Author | zekebuilds-lab |
| Repository | zekebuilds-lab/captcha-mcp |
| Popularity | 1 GitHub stars |
| Category | Security |
| Security | Low risk (84/100) |
| Rank | #3,613 of 4,418 MCP servers; #210 in Security |
| License | MIT |
| Last commit | 2026-08-14 |
| Runs | Locally |
| Language | TypeScript |
| Platforms | macOS, Windows, Linux |
Is captcha-mcp safe to install?
captcha-mcp scores 84/100 on the MCPMods security check: Low risk. Things to review: can take actions such as send, write or deploy. It passed 4 of 6 checks.
MCP server results come from listing signals: who publishes it, where your data goes and what it can do. The code itself is not scanned yet.
| Check | Result |
|---|---|
| Community-built server | Note |
| Runs on your machine only | Pass |
| No credentials mentioned | Pass |
| Can take actions such as send, write or deploy | Review |
| No code execution | Pass |
| Source on GitHub | Pass |
How do I install captcha-mcp?
- Find the launch command. The README says how the server starts (npx, uvx, docker or a remote URL) and which API keys it needs.
https://github.com/zekebuilds-lab/captcha-mcp
- Add it to Claude Code. Replace the part after -- with the command from the README. Remote servers use --transport http with a URL.
claude mcp add captcha-mcp -- <command from README> claude mcp add --transport http captcha-mcp <server-url>
- Check it connected. This lists your MCP servers and their status.
claude mcp list
Or ask Claude to set it up
Paste this into Claude Code and it installs captcha-mcp for you:
Add the "captcha-mcp" MCP server from https://github.com/zekebuilds-lab/captcha-mcp to Claude Code. Read its README for the launch command and any API keys I need, run claude mcp add, then check that it connects.