FCaptcha
Open source invisible CAPTCHA that catches AI agents
Details
- External ID
- 1251637
- Source
- PH
- Company
- —
- Product
- FCaptcha
- Website domain
- producthunt.com
- Launched
- Sept. 22, 2026
- Cohort
- —
- Upvotes
- 2
- Upvotes percentile
- 0.7405388069275176
- Tags
- Open Source, Developer Tools, Security
- Fetched at
- Sept. 24, 2026, 4:20 a.m.
- Updated at
- Sept. 24, 2026, 4:20 a.m.
Description
FCaptcha is a self-hosted, MIT-licensed CAPTCHA with no puzzle. One click or fully invisible. It catches headless browsers, Puppeteer, Playwright, Selenium, and the new wave of AI agents driving real browsers (vision click bots, computer-use agents). Verifies Web Bot Auth signed crawlers so polite agents get through. Drop-in for Turnstile, reCAPTCHA and hCaptcha: same siteverify contract. No cookies, no third-party data. WCAG 2.2 AA, false-positive budget enforced in CI. Go, Node or Python.
Enrichment
- Theme
- task-specific ai agents and assistants
- Vertical
- Security
- Function
- Dev tools
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- open-source invisible bot detection for developers
- Manually corrected
- False
Could you build this?
Partial Serving challenge tokens and verification endpoints is straightforward, but developing effective behavioral and fingerprinting algorithms to accurately distinguish AI vision agents and headless browsers without false positives requires advanced anti-bot engineering.
What it would actually take: The client script needs deep browser fingerprinting (Canvas, WebGL, AudioContext, DOM-mutation timing, and event dispatch analysis) combined with a high-throughput backend analyzing mouse dynamics and Web Bot Auth cryptographic signatures. Keeping ahead of stealth browser automation libraries (like puppeteer-extra-stealth) requires ongoing security and reverse engineering research.
Competitors
Other products that read as similar to this one — 46 launches clear the similarity bar, closest 8 shown.
Attention rank: #10 of 47 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 306 days after the earliest competitor.
- FireClaw · hn · 2026-03-17 · 5 upvotes · similarity 0.42
- HumanEyes: AI Shield · ph · 2026-09-22 · 2 upvotes · similarity 0.41
- Agent-browser-shield · hn · 2026-06-03 · 7 upvotes · similarity 0.41
- My agents are building a secure fork of OpenClaw · hn · 2026-02-13 · 9 upvotes · similarity 0.40
- Alovia · ph · 2026-09-29 · 1 upvotes · similarity 0.40
- HCaptcha Reverse Engineered · hn · 2026-03-31 · 5 upvotes · similarity 0.39
- Captcha to detect bots with a simple question · hn · 2026-04-09 · 5 upvotes · similarity 0.38
- OpenClaw 2.0 · ph · 2026-09-02 · 210 upvotes · similarity 0.36
Other launches for this product
- No other launches for this product.
Same idea, different domain
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