API Reference
Overview
Base URL, authentication, content type, and response headers.
Base URL
https://request.usestring.ai/v1Authentication
All endpoints require a Bearer API key in the Authorization header. See
Authentication.
Authorization: Bearer YOUR_API_KEYContent type
Request bodies are JSON. Send Content-Type: application/json.
Endpoints
| Method | Path | Description |
|---|---|---|
POST | /fetch | Intelligent web fetch. |
POST | /search | Structured web search results. |
POST | /sitemap | Whole-site URL discovery (async jobs). |
GET | /wss | Remote CDP browser (WebSocket upgrade). |
POST | /contexts | Create a reusable browser profile. |
GET | /contexts | List browser profiles. |
GET | /contexts/{contextId} | Inspect a profile and its latest save. |
DELETE | /contexts/{contextId} | Delete a browser profile. |
Response headers
API responses include diagnostic headers when applicable:
| Header | Description |
|---|---|
x-request-duration-ms | Total request duration in milliseconds. |
x-data-transfer-bytes | Estimated response payload plus header bytes before compression. |
x-status-code | The destination's original HTTP status code. Also set on a failed fetch that reached the destination — see Errors. |
x-final-url | /fetch only. The URL the response was served from, after any redirects, or the requested URL if there was no redirect. JSON bodies carry the same value as finalUrl. Sent on error responses too; omitted only when the request body has no valid url. See Final URL. |
x-origin-etag | The destination's ETag, kept separate from the API representation's own validators. |
x-origin-last-modified | The destination's Last-Modified value, suitable for a later If-Modified-Since request. |
x-protocol-fallback-url | Present only when an https:// URL could not be reached over TLS and was fetched over plain http:// instead. The value is the http:// URL fetched. See HTTPS fallback. |
x-request-id | Request identifier, useful when contacting support. |
x-billed-request-type | Billed /fetch classification. See Billed request type. |
x-json-schema-applied | jsonSchema requests only. true — the body is the extracted object; false — it is the fallback envelope. |
x-json-schema-fallback-reason | Present only with x-json-schema-applied: false. Same value as the body's reason; see fallback details. |
x-iframes-truncated | /fetch only. true when includeIframes or captureIframes left an iframe or its content out; absent otherwise. |
x-wait-until-timed-out | /fetch only. true when the page was read, or the actions ran, before it reached the request's waitUntil state; absent otherwise. |
Billed request type
A billed /fetch response includes x-billed-request-type, which identifies the request strategy and proxy class used
for billing:
| Value | Request strategy | Proxy class |
|---|---|---|
request_standard | Request-based | Standard |
request_premium | Request-based | Premium |
browser_standard | Browser-based | Standard |
browser_premium | Browser-based | Premium |
search | Search | — |
search marks a Google results URL that /fetch answered through Search; it bills at the
search rate.
Errors & limits
- Errors — status codes and error response shapes.
- Rate limits — request rate and
429handling.