web.headers

stable 2 credits

HTTP status, response headers (cookie values redacted) and redirect chain of a URL.

GET /v1/web/headers

What you get#

One Web record in Onekey's unified shape, in data. If the record does not exist you get a 404 not_found and are not charged.

Also known as: /on_page/page on APIs that nest their paths. See Alternatives and equivalents.

What it costs#

2 credits for a fresh fetch, charged only when it succeeds.
Free when served from cache (0.2 credit for a cached response over 100 KB).
Free if the request is invalid (never charged) or the source fails or reports not found (refunded).

Parameters#

Name	Type	Required	Default	What it is	Constraints
`url`	string	yes	(required)	Absolute http(s) URL of the page (ports 80/443 only; private/internal hosts are refused)	max 2048 chars; must match `https?://[A-Za-z0-9](?:[A-Za-z0-9.-]{0,251}[A-Za-z0-9])?(?::(?:80\|443))?(?:[/?][\x21-\x5b\x5d-\x7e]*)?`; trimmed

Request#

curl "https://api.onekey.dev/v1/web/headers?url=https%3A%2F%2Fwww.python.org%2F" \
  -H "x-api-key: YOUR_API_KEY"

Try it

Add your key to run this call right here. No key? Get one free. The key stays in this tab.

Recorded response#

A real Web response, recorded and returned in Onekey's shape. Fields the platform does not provide are null.

json

{
  "success": true,
  "data": {
    "content": {
      "url": "https://www.python.org/"
    },
    "ext": {
      "httpStatus": 200,
      "https": true,
      "redirectCount": 0,
      "headers": {
        "connection": "keep-alive",
        "content-length": "52588",
        "server": "nginx",
        "via": "1.1 varnish, 1.1 varnish, 1.1 varnish",
        "x-frame-options": "SAMEORIGIN",
        "content-security-policy-report-only": "object-src 'none'; form-action 'self'; style-src 'self' 'unsafe-inline' https://ajax.googleapis.com; base-uri 'self'; default-src 'self'; script-src 'self' 'nonce-ji8kEvh74xHsJpBawxmIgQ==' https://analytics.python.org https://media.ethicalads.io https://ajax.googleapis.com; font-src 'self' data:; img-src 'self' data: https://media.ethicalads.io; frame-ancestors 'self'; connect-src 'self' https://console.python.org https://analytics.python.org https://server.ethicalads.io https://2p66nmmycsj3.statuspage.io; report-uri https://o20004.ingest.us.sentry.io/api/39935/security/?sentry_key=95f826ce8a6d47e9ab5dbb055c24eb74",
        "content-type": "text/html; charset=utf-8",
        "accept-ranges": "bytes",
        "date": "Mon, 28 Sep 2026 20:12:15 GMT",
        "age": "1038",
        "x-served-by": "cache-iad-kcgs7200050-IAD, cache-iad-kcgs7200050-IAD, cache-iad-kcgs7270046-IAD, cache-bom-vanm7210082-BOM",
        "x-cache": "MISS, HIT, HIT",
        "x-cache-hits": "0, 133, 17",
        "x-timer": "S1790626335.092565,VS0,VE0",
        "vary": "Cookie",
        "strict-transport-security": "max-age=63072000; includeSubDomains; preload"
      },
      "contentType": "text/html; charset=utf-8",
      "contentLength": 52588,
      "server": "nginx",
      "poweredBy": null,
      "cacheControl": null,
      "lastModified": null,
      "etag": null,
      "contentEncoding": null,
      "chain": [
        {
          "url": "https://www.python.org/",
          "status": 200,
          "location": null
        }
      ]
    }
  },
  "metadata": {
    "platform": "web",
    "endpoint": "headers",
    "cached": false,
    "stale": false,
    "age_s": 0,
    "fetched_at": "2026-01-01T12:00:00+00:00",
    "credits_charged": 2,
    "request_id": "7f3a9c2e5b1d4c8fa2e6d0b9c4f18e37"
  },
  "error": null
}

Field mapping#

How this endpoint's source fields become Onekey's unified schema. Fields the source lacks come back as null.

Source path	Onekey field	Transform
`finalUrl`	`content.url`	`safeUrl`
`status`	`ext.httpStatus`	`toNumber`
`https`	`ext.https`	`toBoolean`
`redirectCount`	`ext.redirectCount`	`toNumber`
`headers`	`ext.headers`	-
`contentType`	`ext.contentType`	-
`contentLength`	`ext.contentLength`	`toNumber`
`server`	`ext.server`	-
`poweredBy`	`ext.poweredBy`	-
`cacheControl`	`ext.cacheControl`	-
`lastModified`	`ext.lastModified`	-
`etag`	`ext.etag`	-
`contentEncoding`	`ext.contentEncoding`	-
`chain`	`ext.chain`	-

Caching and freshness#

Fresh for about 10 minutes. Repeat calls in that window are served from cache and are free.
Between 10 minutes and 1 hour the cached copy is still served instantly and marked stale: true while Onekey refreshes it in the background.
If the source is down when a refresh is needed, the last copy can be served for up to 1 hour more (marked stale).
A "not found" is remembered for 2 minutes and is free.
The cache is shared across all customers, which is what keeps repeat calls cheap.

What can go wrong#

Status	Code	What to do
401	`unauthorized`	Check the `x-api-key` header.
402	`insufficient_credits`	Add credits; your balance must cover the price.
404	`not_found`	That record does not exist. Free; do not retry.
422	`invalid_params`	Fix the parameters using the table above. Free.
429	`rate_limited`	Wait `Retry-After` seconds, then retry.
502	`upstream_error`	The source failed. Refunded; retry with backoff.

See Errors for the full list and retry guidance.

Status: stable (verified against the live source).