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 | Google search results. |
POST | /sitemap | Whole-site URL discovery (async jobs). |
GET | /wss | Remote CDP browser (WebSocket upgrade). |
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 (raw/markdown/extraction paths). |
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. Why extraction fell back, and whether it was billed. |
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 |
Errors & limits
- Errors — status codes and error response shapes.
- Rate limits — request rate and
429handling.