Ross ROSS = Recommend OSS · open-source software intelligence for agents

tiagozip/cap

Free, open-source and self-hosted CAPTCHA alternative to reCAPTCHA. Privacy-first and powered by proof-of-work and instrumentation challenges. observed · 2026-08-28

github.com/tiagozip/cap · homepage · JavaScript · NOASSERTION (other) observed · 2026-08-28

Health v2 · maintenance only

81/100

  • Activity 97
  • Release rhythm 82
  • Longevity 42

Flags: no_license

How is this computed?

round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.

  • gap_med: 0.0
  • age_days: 599
  • days_rel: 42
  • days_push: 19
  • n_releases_24m: 121

Full methodology

Adoption not part of the score

7610 stars · 551 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Cap is a lightweight, open-source, self-hosted CAPTCHA alternative to reCAPTCHA, hCaptcha, and Cloudflare Turnstile. It uses invisible proof-of-work (SHA-256 via WASM or time-lock challenges) plus instrumentation challenges to verify real browsers, with no tracking or visual puzzles.

Use cases

  • replace reCAPTCHA with a self-hosted captcha
  • stop bot signups and spam form submissions
  • add anti-bot protection without visual puzzles
  • self-host a privacy-first captcha for GDPR compliance
  • protect login and comment forms from scrapers
  • migrate from reCAPTCHA without rewriting verification code
  • run an invisible captcha widget in the background

When to choose

  • you need a self-hosted, privacy-compliant captcha with no third-party telemetry
  • you want a tiny (~20kb) widget with zero dependencies
  • you want reCAPTCHA siteverify API compatibility for easy migration
  • you need accessibility-friendly protection without image puzzles

When to avoid

  • you need advanced human-verification like behavioral analysis against sophisticated bot farms
  • you cannot run your own server or Docker container
  • you require a fully managed SaaS captcha service

Facets

library · maturity active

security middleware wasm self-hosted security web-development privacy self-hosted self-hosted browser cross-platform captcha proof-of-work anti-bot antispam anti-scraper recaptcha-alternative privacy-first invisible-captcha web-server docker nodejs

3 sources

Member repositories

RepositoryRoleHealth v2
tiagozip/capmain81

For agents

markdown · JSON · MCP: product_card(name="tiagozip/cap")

Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem