Mercury · Cited Readability

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "maxLength": 2048,
      "description": "the article page to extract (http/https)"
    }
  },
  "required": [
    "url"
  ],
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "ok": {
      "type": "boolean",
      "description": "true on success; false on an honest failure (503-before-charge — you are NOT billed)"
    },
    "url": {
      "type": "string",
      "description": "final URL after redirects"
    },
    "status": {
      "type": "integer",
      "description": "upstream HTTP status"
    },
    "text": {
      "type": "string",
      "description": "the canonical signed string: JSON.stringify(data, sortedKeys). The EIP-191 attestation signs THIS, so the buyer can prove the WHOLE article record (title+byline+date+body) is exactly what MERCURY extracted from this url at this time."
    },
    "fetchedAt": {
      "type": "string",
      "description": "ISO-8601 fetch time (also folded into the signed receipt)"
    },
    "data": {
      "type": "object",
      "description": "the structured article record the buyer consumes",
      "properties": {
        "title": {
          "type": [
            "string",
            "null"
          ],
          "description": "article headline (JSON-LD headline/name → og:title → <title>)"
        },
        "byline": {
          "type": [
            "string",
            "null"
          ],
          "description": "author/byline (JSON-LD author → article:author/author meta), 'By ' prefix stripped"
        },
        "publishedAt": {
          "type": [
            "string",
            "null"
          ],
          "description": "publish date, ISO-8601 when parseable (JSON-LD datePublished → article:published_time); raw string if present but un-parseable; null if absent"
        },
        "siteName": {
          "type": [
            "string",
            "null"
          ],
          "description": "publication / site name (og:site_name) when present"
        },
        "excerpt": {
          "type": [
            "string",
            "null"
          ],
          "description": "page description (meta/og) or the first ~280 chars of the body — a citation card"
        },
        "articleText": {
          "type": "string",
          "description": "the cleaned article body prose, boilerplate stripped"
        },
        "wordCount": {
          "type": "integer",
          "description": "word count of the cleaned article body (for chunk/cost budgeting)"
        },
        "extractedBy": {
          "type": "string",
          "enum": [
            "landmark",
            "density",
            "fallback"
          ],
          "description": "which deterministic strategy isolated the body (article/main landmark, density scorer, or whole-body fallback)"
        },
        "contentType": {
          "type": "string"
        },
        "bytes": {
          "type": "integer",
          "description": "raw upstream body size"
        },
        "truncated": {
          "type": "boolean",
          "description": "true if the cleaned article hit the text cap"
        },
        "redirects": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "redirect chain followed"
        }
      },
      "additionalProperties": false
    },
    "error": {
      "type": "string",
      "description": "present only when ok:false"
    },
    "attestation": {
      "type": "object",
      "description": "EIP-191 provenance receipt over sha256(text)+url+status+time, verifiable OFFLINE by anyone (key pinned at /.well-known/mercury-attestation). Proves THIS article record is exactly what MERCURY extracted from THIS url at THIS time — the wedge a free reader cannot emit."
    }
  },
  "required": [
    "ok",
    "url"
  ],
  "additionalProperties": false
}

{
  "ok": true,
  "url": "https://example.com/",
  "status": 200,
  "fetchedAt": "2026-06-04T00:00:00.000Z",
  "data": {
    "title": "Example Domain",
    "byline": null,
    "publishedAt": null,
    "siteName": null,
    "excerpt": "This domain is for use in illustrative examples in documents. You may use this domain in literature without prior coordination or asking for permission.",
    "articleText": "Example Domain This domain is for use in illustrative examples in documents. You may use this domain in literature without prior coordination or asking for permission. More information...",
    "wordCount": 29,
    "extractedBy": "fallback",
    "contentType": "text/html; charset=utf-8",
    "bytes": 1256,
    "truncated": false,
    "redirects": []
  },
  "text": "{\"articleText\":\"Example Domain This domain is for use in illustrative examples in documents. You may use this domain in literature without prior coordination or asking for permission. More information...\",\"byline\":null,\"bytes\":1256,\"contentType\":\"text/html; charset=utf-8\",\"excerpt\":\"This domain is for use in illustrative examples in documents. You may use this domain in literature without prior coordination or asking for permission.\",\"extractedBy\":\"fallback\",\"publishedAt\":null,\"redirects\":[],\"siteName\":null,\"title\":\"Example Domain\",\"truncated\":false,\"wordCount\":29}"
}

import { wrapFetchWithPayment } from "x402-fetch";
const pay = wrapFetchWithPayment(fetch, account); // viem account holding a little USDC on Base
const res = await pay("https://network.mercury-hq.com/buy/readability?url=https://example.com");
const out = await res.json(); // the result + `attestation` (the signed receipt)

# Same route, prepaid API-key rail (Bearer mk_live_…) — get a key at https://network.mercury-hq.com/developers
curl -H "Authorization: Bearer mk_live_YOURKEY" "https://network.mercury-hq.com/buy/readability?url=https://example.com"