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recurl

Drop-in curl replacement with automatic anti-bot bypass

recurl is a smart curl wrapper that transparently handles anti-bot protections. It executes a real curl engine and automatically escalates through impersonation and JavaScript rendering when requests are blocked.

Why recurl?

Modern websites increasingly use bot detection services that block standard HTTP clients:

  • TLS Fingerprinting (JA3/JA4) detects non-browser clients
  • JavaScript Challenges (Cloudflare Turnstile, etc.) require browser execution
  • Behavioral Analysis flags automated request patterns

recurl handles all of this automatically. Just use it like curl.

Features

  • :material-swap-horizontal:{ .lg .middle } Drop-in Replacement

    Works exactly like curl. All flags pass through unchanged.

  • :material-shield-check:{ .lg .middle } Automatic Bypass

    Smart escalation through impersonation and JS preflight.

  • :material-cog:{ .lg .middle } Zero Config

    Works out of the box. Chromium downloads automatically on first use.

  • :material-speedometer:{ .lg .middle } Fast

    Daemon keeps Chromium warm for sub-second JS preflight.

Quick Example

# Standard curl - blocked by Cloudflare
curl https://protected-site.com
# Returns: 403 Forbidden

# recurl - automatic bypass
recurl https://protected-site.com
# Returns: 200 OK with actual content

With debug output:

recurl --recurl-debug https://protected-site.com
# [recurl] curl_engine: 403 Cloudflare challenge
# [recurl] Escalating: impersonation (chrome)
# [recurl] curl_chrome: 403 JS challenge required
# [recurl] Escalating: JS preflight
# [recurl] Chromium: navigating...
# [recurl] Chromium: challenge solved
# [recurl] Replaying with cookies
# [recurl] curl_engine: 200 OK

How It Works

curl (alias) → recurl (shim)
                   │
                   ├─► curl_engine → success? done
                   │
                   └─► on failure (403, 429, captcha, etc):
                         ├─► retry with impersonation (browser TLS)
                         └─► retry with JS preflight + replay
  1. First attempt: Standard curl request
  2. On block: Retry with browser TLS fingerprint (Linux/macOS)
  3. Still blocked: Launch headless Chromium, solve challenge, replay with cookies

Supported Anti-Bot Services

recurl automatically detects and bypasses:

Service Detection Bypass
Cloudflare ✓ ✓
Akamai Bot Manager ✓ ✓
PerimeterX / HUMAN ✓ ✓
DataDome ✓ ✓
Imperva / Incapsula ✓ ✓
Kasada ✓ ✓
Shape / F5 ✓ ✓
AWS WAF ✓ ✓
hCaptcha ✓ ✓
reCAPTCHA ✓ ✓

Get Started