MERCURY Cited Readability API

openapi: 3.2.0
info:
  title: MERCURY x402 storefront Cited Readability API
  version: '1'
  x-spec: mercury-storefront/1
  description: Agent-payable resources over HTTP 402 (x402). LIVE — Base mainnet, real USDC, no token. Only currently-deliverable routes are listed (web-fetch is the live paid SKU; mints are gated off). Free discovery at /.well-known/x402, /x402/discovery, /catalog, and /manifest.
servers:
- url: https://network.mercury-hq.com
tags:
- name: cited-readability
paths:
  /buy/readability:
    get:
      summary: MERCURY Cited Readability
      description: 'URL → a clean ARTICLE record { title, byline, publishedAt, article text } with boilerplate (nav/header/footer/sidebar/ads/share-bars/comment-forms) stripped via deterministic DOM density heuristics, plus a signed provenance receipt pinning the cleaned article to its source — the clean-citation primitive distinct from raw markdown. Deterministic (no LLM): same URL + same source bytes ⇒ byte-identical output.'
      operationId: buy_cited_readability
      tags:
      - cited-readability
      responses:
        '200':
          description: Delivered after the x402 payment settles on Base mainnet.
          content:
            application/json:
              schema:
                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
        '402':
          description: Payment Required — retry with an x402-signed payment (e.g. x402-fetch). Terms are in the challenge body (x402 v1).
      parameters:
      - name: url
        in: query
        required: true
        schema:
          type: string
          maxLength: 2048
          description: the article page to extract (http/https)
        description: the article page to extract (http/https)
      x-payment-info:
        protocols:
        - x402
        scheme: exact
        price: $0.005
        currency: USDC
        network: base
        networkCaip2: eip155:8453
        testnet: false
        asset: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913'
        payTo: '0xe10B9d44e72A29B9c19da02981FFCd875308e3C1'
        facilitator: https://api.cdp.coinbase.com/platform/v2/x402
        x402Version: 1
      x-x402:
        scheme: exact
        price: $0.005
        currency: USDC
        network: base
        networkCaip2: eip155:8453
        asset: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913'
        payTo: '0xe10B9d44e72A29B9c19da02981FFCd875308e3C1'
        facilitator: https://api.cdp.coinbase.com/platform/v2/x402
        testnet: false
        maxTimeoutSeconds: 60
x-payment-info:
  protocols:
  - x402
  network: base
  currency: USDC
  payTo: '0xe10B9d44e72A29B9c19da02981FFCd875308e3C1'
  facilitator: https://api.cdp.coinbase.com/platform/v2/x402
  testnet: false
  spec: mercury-storefront/1