API referenceTask typesCloudflare Challenge

Cloudflare Challenge

The interstitial page that says "Just a moment..." and returns 403 before it lets you through. What comes back is a cookie, not a form token, and it is tied to one address and one user agent.

Task types

Type string	Proxy	Use it for
`AntiCloudflareTask`	Required	The full page interstitial, managed or JavaScript challenge.

Task object

Field	Type	Required	What it is
`type`	String	Yes	`AntiCloudflareTask`.
`websiteURL`	String	Yes	The address that returned the interstitial.
`proxy`	String	Yes	A static or sticky address, in either shape. See using proxies.
`userAgent`	String	No	The user agent you will present afterwards. Chrome only. If you leave it out we pick one and return it.
`html`	String	No	The body of the 403 you received. Passing it saves us a round trip and usually a few seconds.

Example

POST/createTask

{
  "clientKey": "YOUR_API_KEY",
  "task": {
    "type": "AntiCloudflareTask",
    "websiteURL": "https://example.com/",
    "proxy": "http:192.0.2.40:8080:user:pass",
    "userAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36",
    "html": "<!DOCTYPE html><html lang=\"en-US\"><head><title>Just a moment...</title>..."
  }
}

JSON

{
  "errorId": 0,
  "taskId": "df944101-64ac-468d-bc9f-41baecc3b8ca",
  "status": "ready",
  "solution": {
    "cookies": {
      "cf_clearance": "Bcg6jNLzTVaa3IsFhtDI.e4_LX8p7q7zFYHF7wiHPo...bbdfwBEi3tNNQpc"
    },
    "token": "Bcg6jNLzTVaa3IsFhtDI.e4_LX8p7q7zFYHF7wiHPo...bbdfwBEi3tNNQpc",
    "userAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36"
  }
}

Solution field	What to do with it
`cookies`	Merge into your session cookie jar. `cf_clearance` is the one that matters.
`token`	The same clearance value on its own, for clients that set cookies by hand.
`userAgent`	Send every later request with this exact string. A mismatch voids the cookie.

Using the cookie

Three things have to match on every request after the solve, or the challenge comes back: the clearance cookie, the address, and the user agent. Change any one and the other two stop counting.

Python

import requests, jevcha

jevcha.api_key = "YOUR_API_KEY"
PROXY = "http://user:pass@192.0.2.40:8080"
UA = ("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 "
      "(KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36")

s = requests.Session()
s.proxies = {"http": PROXY, "https": PROXY}
s.headers["User-Agent"] = UA

first = s.get("https://example.com/")
if first.status_code == 403:
    solution = jevcha.solve({
        "type": "AntiCloudflareTask",
        "websiteURL": "https://example.com/",
        "proxy": PROXY,
        "userAgent": UA,
        "html": first.text,
    })
    s.cookies.update(solution["cookies"])

print(s.get("https://example.com/").status_code)

Last updated 21 September 2026