Chris

---

Back to Home 中文文档

hCaptcha Preflight API (Enterprise)

When to Use

Use when a website has noticeable score detection to improve verification pass rates.

Description

Used to maintain consistent contextual proxy region, UserAgent, and other data with the business context.

🚨🚨🚨

After obtaining the region (e.g., hk, gb, us), the proxy used must correspond to that region. The region obtained through this interface MUST be applied to your proxy; otherwise, this process becomes meaningless (e.g. region=gb, user-gb:pwd@ip:port).

Request URL (POST):

API Endpoint
http://api.nocaptcha.io/api/wanda/hcaptcha/preflight

Request Headers:

Header	Description	Required
Content-Type	application/json	Yes

POST Data (JSON):

Parameter	Type	Description	Required
sitekey	String	hCaptcha integration key	Yes

Response Data (JSON):

Parameter	Type	Description
success	Boolean	Whether the call succeeded
data.data	Object	Preflight response data
data.data.preflight_uuid	String	Preflight request ID
data.data.region	String	Country abbreviation for preflight
cost	String	Verification time (ms)

JSON Example

{
    "success": true,
    "data": {
        "preflight_uuid": "b5e404b6-55ca-4672-a83f-9a5f3e2e9882",
        "data": {
            "region": "ca",
            "navigator": {
                "userAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36"
            },
            ...
        }
    }
}