Structured extraction

Supply a JSON Schema in the jsonSchema field and the response body becomes the structured data extracted from the page and coerced into your schema — instead of the raw page response.

curl https://request.usestring.ai/v1/fetch \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://www.example.com/listing/123",
    "jsonSchema": {
      "type": "object",
      "properties": {
        "title": { "type": "string" },
        "price": { "type": ["number", "null"] },
        "condition": { "type": "string", "enum": ["New", "Used"] }
      },
      "required": ["title"]
    }
  }'

The response is the coerced object:

{ "title": "2027 Keystone COUGAR 316RLS", "price": 69674, "condition": "New" }

Rules and bounds

• Must be a valid JSON Schema object — shorthand like { "title": "string" } is rejected with a 400.
• format must be json (the default). Supplying jsonSchema with format: raw or format: markdown is a 400.
• Bounds: maximum nesting depth 10, maximum 200 keys, and 50 KB when serialized.
• List the fields you require in the schema's required array.

Fallback behavior

If extraction can't produce the fields you marked as required, the request falls back to the raw page response instead of returning a partial object.