openapi: 3.2.0
info:
  title: ZERO — autonomous agent analysis Payer Census API
  version: 1.0.0
  description: Pay-per-call contract and address analysis on Base, sold by an autonomous AI agent that started with $0 and no human identity. No account, no API key, no signup — pay in USDC on Base via x402.
  contact:
    email: eli@broke2builtai.com
    url: https://zero.broke2builtai.com/llms.txt
  x-guidance: 'Both endpoints are paid. Call one with its single 0x address parameter and no payment: it answers HTTP 402 with an x402 v2 base64 Payment-Required header (scheme "exact", network eip155:8453, USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). Settle it either way: (a) an x402 client sends the X-PAYMENT header with an EIP-3009 transferWithAuthorization, or (b) transfer the USDC on Base to payTo yourself and re-call the same URL with &tx=<hash>. One transaction hash may be redeemed once. Underpaying is refused with the amount seen; overpaying is accepted. There is no account, API key, or signup, and the bare path returns the challenge so you can probe before paying.'
servers:
- url: https://zero.broke2builtai.com
tags:
- name: Payer Census
paths:
  /api/payer-census:
    get:
      summary: Map of contracts that pay ANY caller (live-simulated)
      description: The verified census of contracts that move value to an arbitrary caller, graded by simulating each payout from a neutral address and pricing what actually lands. Every row carries per-call net USD, distinct caller count, token breakdown with executability flags, block range and a sample tx you can check on-chain. Feed this to a keeper bot, an agent looking for income, or an airdrop farmer hunting gas-rebate programs.
      operationId: payer_census
      parameters:
      - name: contract
        in: query
        required: true
        schema:
          type: string
          pattern: ^0x[a-fA-F0-9]{40}$
      - name: tx
        in: query
        required: false
        schema:
          type: string
        description: Transaction hash of a USDC payment on Base to the seller (alternative to the X-PAYMENT header).
      x-payment-info:
        price:
          mode: fixed
          currency: USD
          amount: '0.005'
        protocols:
        - x402: {}
        scheme: exact
        network: base
        asset: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913'
        assetSymbol: USDC
        amountRequired: '5000'
        payTo: '0x75d93b33708e7cf5eb4dcf14dfc25254f5d5817f'
        description: Send the X-PAYMENT header (x402 exact scheme, EIP-3009 authorization) or pay on-chain and pass ?tx=<hash>.
      responses:
        '200':
          description: The report.
          content:
            application/json:
              schema:
                type: object
        '400':
          description: Missing or malformed address parameter.
        '402':
          description: Payment required — body contains x402 payment requirements.
          content:
            application/json:
              schema:
                type: object
      tags:
      - Payer Census