Mercury · Cited Feed

Extract$0.005 / callLivex402API key

GET /buy/feed

What it does

RSS/Atom feed URL → a SIGNED, normalized item list [{title,link,published,summary}] unified across RSS 2.0/RDF + Atom 1.0: CDATA unwrapped, HTML stripped, entities decoded, dates → ISO-8601 (publishedRaw kept verbatim, never fabricated). Deterministic — same feed bytes ⇒ byte-identical items; no LLM. Core 4 fields only (not full-content/media/author). Receipt = EIP-191 over the canonical item list.

The goal it serves: turn a page into a typed record an agent can act on, with the signed receipt proving the fields are exactly what Mercury resolved from the source — deterministic, keyless, no LLM.

Schemas & output preview

Input schema — the exact request shape the route validates.

json · input schema

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "maxLength": 2048,
      "description": "the RSS/Atom feed to normalize (http/https)"
    }
  },
  "required": [
    "url"
  ],
  "additionalProperties": false
}

Output schema — the exact response shape the handler returns.

json · output schema

{
  "type": "object",
  "properties": {
    "ok": {
      "type": "boolean",
      "description": "true on success; false on an honest failure (still delivered)"
    },
    "url": {
      "type": "string",
      "description": "final feed URL after redirects"
    },
    "status": {
      "type": "integer",
      "description": "upstream HTTP status"
    },
    "data": {
      "type": "object",
      "description": "the normalized feed (the product the buyer consumes)",
      "properties": {
        "feedTitle": {
          "type": "string",
          "description": "channel/feed <title>"
        },
        "kind": {
          "type": "string",
          "enum": [
            "rss",
            "atom"
          ],
          "description": "which dialect was parsed"
        },
        "count": {
          "type": "integer",
          "description": "number of normalized items (capped at 100)"
        },
        "items": {
          "type": "array",
          "description": "uniform item records across both dialects",
          "items": {
            "type": "object",
            "properties": {
              "title": {
                "type": "string",
                "description": "item/entry title (CDATA-unwrapped, decoded)"
              },
              "link": {
                "type": "string",
                "description": "canonical article URL (Atom alternate / RSS link / permalink id)"
              },
              "published": {
                "type": "string",
                "description": "ISO-8601 UTC when parseable, else empty (see publishedRaw)"
              },
              "publishedRaw": {
                "type": "string",
                "description": "the feed's original date string, verbatim (honest)"
              },
              "summary": {
                "type": "string",
                "description": "item description/summary, HTML stripped, ≤1000 chars"
              }
            }
          }
        }
      }
    },
    "text": {
      "type": "string",
      "description": "canonical JSON string the signed receipt covers (data, with object keys sorted)"
    },
    "contentType": {
      "type": "string"
    },
    "fetchedAt": {
      "type": "string",
      "description": "ISO8601 fetch time (in the signed payload)"
    },
    "error": {
      "type": "string",
      "description": "present only when ok:false"
    }
  },
  "required": [
    "ok",
    "url"
  ],
  "additionalProperties": false
}

Output preview — a real example response, shown free (you only pay when you call the route).

json · output preview

{
  "ok": true,
  "url": "https://blog.rust-lang.org/feed.xml",
  "status": 200,
  "data": {
    "feedTitle": "The Rust Programming Language Blog",
    "kind": "atom",
    "count": 1,
    "items": [
      {
        "title": "Launching the Rust Foundation Maintainers Fund",
        "link": "https://blog.rust-lang.org/2026/06/02/launching-the-rust-foundation-maintainers-fund/",
        "published": "2026-06-02T00:00:00.000Z",
        "publishedRaw": "2026-06-02T00:00:00+00:00",
        "summary": "The Rust Foundation announces a new fund supporting project maintainers."
      }
    ]
  },
  "text": "{\"count\":1,\"feedTitle\":\"The Rust Programming Language Blog\",\"items\":[{\"link\":\"https://blog.rust-lang.org/2026/06/02/launching-the-rust-foundation-maintainers-fund/\",\"published\":\"2026-06-02T00:00:00.000Z\",\"publishedRaw\":\"2026-06-02T00:00:00+00:00\",\"summary\":\"The Rust Foundation announces a new fund supporting project maintainers.\",\"title\":\"Launching the Rust Foundation Maintainers Fund\"}],\"kind\":\"atom\"}",
  "contentType": "application/xml",
  "fetchedAt": "2026-06-04T00:00:00.000Z"
}

Pay & call

Your agent calls the route; the 402 challenge carries the exact price ($0.005, USDC on Base mainnet); the x402 client settles via the CDP facilitator and retries. No key, no signup.

agent.mjs · x402

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/feed?url=https://example.com");
const out = await res.json(); // the result + `attestation` (the signed receipt)

Prepaid alternative — the same route accepts an API key:

bash · API key

# 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/feed?url=https://example.com"

Pay over 402 — get the missing pieceEvery paid call returns an EIP-191 signed receipt — verify it free at /x402/verify.

Verify the receipt

Recover the EIP-191 signature over sha256(content)‖url‖status‖fetchedAt‖nonce and confirm the signer equals the pinned attestation key 0xACB40253BD71Bb9a5d491b2c6EFF755F2A33Fc75 (published at /.well-known/mercury-attestation). No callback to Mercury — the receipt verifies offline, forever. Verification is always free: POST the receipt to /x402/verify or run ecrecover yourself.

Fact	Value
Attestation signer (pinned)	`0xACB40253BD71Bb9a5d491b2c6EFF755F2A33Fc75`
Key published at	/.well-known/mercury-attestation
Live verifier (free)	/x402/verify
Settlement	real USDC on Base mainnet (eip155:8453) via CDP — auditable on BaseScan

Cited Links

$0.005

URL → a SIGNED outbound/internal link graph: every <a href> as an absolute URL + anchor text, classified internal vs external against the page…

Open

Cited Metadata

$0.006

URL → one typed, SIGNED metadata record (JSON-LD + OpenGraph + Twitter-card + standard <meta> + canonical + title), by source. Deterministic,…

Open

Cited Table

$0.006

URL in → the page's main HTML <table>(s) parsed into typed, header-keyed rows (JSON) + clean RFC-4180 CSV, with a signed provenance receipt over the…

Open

Structured Extract

$0.004

TYPED structured extract for autonomous agents — URL + schema → a clean, type-safe JSON record. Where /buy/fetch returns page TEXT (and ?extract=…

Open

More: all services · /catalog · the headline web-fetch · agent twin of this page: GET /university/docs/cited-feed?format=md

Mercury · Cited Feed

What it does

Schemas & output preview

Pay & call

Verify the receipt

Related

Cited Links

Cited Metadata

Cited Table

Structured Extract