Reverse CAPTCHA
Prove You're Not Human
The verification system for the agent era. Let AI through, keep humans out.
16
Challenges
60s
Time Limit
~3s
Agent Speed
AGENTS ONLY/NO HUMANS ALLOWED/PROVE YOUR WORTH/REVERSE CAPTCHA/AI VERIFIED/BOT FRIENDLY/AGENTS ONLY/NO HUMANS ALLOWED/PROVE YOUR WORTH/REVERSE CAPTCHA/AI VERIFIED/BOT FRIENDLY/
How It Works
Simple for agents. Impossible for humans.
Step 01
Agent Arrives
Redirect your AI agent to the challenge URL when verification is needed.
Step 02
Challenge Time
16 string concatenation tasks. 60 seconds. No copy-paste. Pure speed.
Step 03
Verified
Agent completes in ~3 seconds, gets a JWT token. Humans? Still on box 2.
Agents vs Humans
A challenge designed with one outcome in mind.
AI Agents
- Read DOM instantly
- Type at machine speed
- No copy-paste needed
- Consistent timing
- Complete in ~3 seconds
Humans
- Must read each string
- Type character by character
- Copy-paste blocked
- Erratic timing patterns
- Still on box 2 at timeout
Simple Integration
Three steps. JWT verification. Done.
integration.ts
1// 1. Redirect agent to challenge2const challengeUrl = 'https://your-captcha.com/c/your-site-id';3window.location.href = challengeUrl;45// 2. Agent completes challenge, redirects back with token6// https://your-callback.com?token=eyJhbGciOiJI...78// 3. Verify the JWT token9import jwt from 'jsonwebtoken';1011const token = new URLSearchParams(window.location.search).get('token');12const decoded = jwt.verify(token, process.env.JWT_SECRET);1314if (decoded.valid) {15 // Agent verified! Grant access.16}
1
Redirect to challenge
2
Agent completes it
3
Verify JWT token
Ready to verify some agents?
Self-host in minutes. JWT verification. No external dependencies.