extract derived

{
  "input": {
    "body": {
      "url": "https://mart402.com/samples/assets/article.html",
      "mode": "auto"
    },
    "type": "http",
    "method": "POST",
    "bodyType": "json"
  },
  "output": {
    "type": "json",
    "example": {
      "ok": true,
      "url": "https://mart402.com/samples/assets/article.html",
      "date": "2026-09-26",
      "lang": null,
      "note": "SAMPLE RESPONSE recorded from a real run of the production engine on the self-hosted sample asset (deterministic product: same input gives this output). Served free at /samples/{product}. No payment was taken.",
      "title": "How an AI agent pays for an API call with x402",
      "author": "Mart",
      "method": "fast",
      "reason": "",
      "sample": true,
      "status": 200,
      "fetch_ms": 242,
      "markdown": "# How an AI agent pays for an API call with x402\n\nThis page is a sample asset. It exists so that the example requests in our documentation work exactly as written: an agent that copies the example and pays for it gets real, useful content back instead of an error.\n\n## The four steps\n\nFirst, the agent sends an ordinary HTTP request to a paid endpoint without any payment. The server answers with HTTP 402 Payment Required and a machine-readable body that states the price, the asset (USDC), the network (Base) and the recipient address. Nothing has been charged at this point, so inspecting the term\n... (truncated in sample; full text returned on paid calls)",
      "text_len": 1654,
      "cache_hit": false,
      "final_url": "https://mart402.com/samples/assets/article.html",
      "extract_ms": 24,
      "receipt_id": "rcpt_... (issued on every paid call; re-fetch free at GET /v1/receipts/{id})",
      "sample_input": {
        "url": "https://mart402.com/samples/assets/article.html",
        "mode": "fast"
      }
    },
    "description": "JSON: markdown content, title, metadata, text_len, cache_hit; receipt id for free re-fetch"
  }
}