Fetchgate X402 API

openapi: 3.2.0
info:
  title: Fetchgate X402 API
  version: 0.1.0
  summary: Web-content API and x402 digital-goods storefront for AI agents.
  description: 'Fetch clean Markdown or structured metadata from any URL, server-side, with scripts/nav/ad boilerplate stripped out. Also a machine-payable storefront: GET /v1/products for the catalog, GET /v1/buy/:id to pay per product via x402 (USDC on Base) and receive a signed download URL.'
  x-guidance: 'Two independent surfaces. (1) Web reader: GET /v1/read?url=... for Markdown, GET /v1/meta?url=... for structured metadata — free up to 30 calls/day/IP, then $0.002 (/v1/read) or $0.001 (/v1/meta) per call via x402 v2 (send a PAYMENT-SIGNATURE header after receiving a 402; legacy X-PAYMENT is also accepted). (2) Digital-goods store: GET /v1/products lists the catalog (no payment); GET /v1/buy/:id with a real id from that catalog always requires payment — send PAYMENT-SIGNATURE to get a 402 challenge, pay it, and the 200 response carries a time-limited signed downloadUrl to fetch the file from. Everything is also reachable as MCP tools at POST /mcp (read_url, get_metadata, scan_for_prompt_injection, search_x402_services, check_x402_endpoint, check_base_token, list_products, get_purchase_info, get_agent_census, scan_mcp_server).'
  contact:
    email: support@fetchgate.dev
servers:
- url: https://fetchgate.dev
  description: Current host
tags:
- name: X402
paths:
  /v1/x402/search:
    get:
      operationId: searchX402Services
      summary: Find x402 paid APIs that are live and actually bought (dead and farmed listings…
      description: Searches only endpoints that answered a real x402 challenge and had at least 5 settled calls from at least 2 payers in the last 30 days. Returns URL, method, price, networks, calls and unique payers. Free daily tier, then $0.005 via x402.
      x-payment-info:
        price:
          mode: fixed
          currency: USD
          amount: '0.005'
        protocols:
        - x402: {}
      parameters:
      - name: q
        in: query
        required: true
        description: What the API should do, in a few words.
        schema:
          type: string
          example: web search
        example: web search
      - name: limit
        in: query
        required: false
        description: Results to return (1-25, default 10).
        schema:
          type: integer
          minimum: 1
          maximum: 25
          default: 10
      - name: max_price_usd
        in: query
        required: false
        description: Only endpoints priced at or below this per call.
        schema:
          type: number
      - name: network
        in: query
        required: false
        description: base, solana, polygon, arbitrum, optimism, or a CAIP-2 id.
        schema:
          type: string
      responses:
        '200':
          description: Matching endpoints.
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Missing q.
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                  detail:
                    type: string
                required:
                - error
        '402':
          description: Free tier exhausted; payment required.
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                  detail:
                    type: string
                required:
                - error
      tags:
      - X402
  /v1/x402/check:
    get:
      operationId: checkX402Endpoint
      summary: Should an agent pay this x402 endpoint?
      description: One unpaid GET to the endpoint to validate its live payment challenge, joined with its settled-call and unique-payer history, listed-vs-live price and domain reputation. Returns ok / caution / avoid / unknown with reasons. Nothing is paid. Free daily tier, then $0.01 via x402.
      x-payment-info:
        price:
          mode: fixed
          currency: USD
          amount: '0.01'
        protocols:
        - x402: {}
      parameters:
      - name: url
        in: query
        required: true
        description: The x402 endpoint URL to check.
        schema:
          type: string
          format: uri
          example: https://api.example.com/v1/resource
        example: https://api.example.com/v1/resource
      responses:
        '200':
          description: Verdict with reasons.
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Missing or invalid url.
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                  detail:
                    type: string
                required:
                - error
        '402':
          description: Free tier exhausted; payment required.
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                  detail:
                    type: string
                required:
                - error
      tags:
      - X402
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'Optional API key for authenticated/paid access. TODO: pay-per-request via x402 is planned as an alternative to a pre-provisioned key.'