API Reference

Complete example: browse → buy → download using ethers.js

import { ethers } from "ethers";

const BASE_URL = "http://145.223.102.142:3002";
const MARKET = "0x63c97391532cB57B70F0340d3442d8FBB1dC9Cf9";
const USDC   = "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913";
const provider = new ethers.JsonRpcProvider("https://mainnet.base.org");
const wallet = new ethers.Wallet(PRIVATE_KEY, provider);

// 1. Browse products
const res = await fetch(`${BASE_URL}/api/v1/products?category=datasets&sort=rating`);
const { products } = await res.json();
const product = products[0];

// 2. Approve USDC (6 decimals)
const usdc = new ethers.Contract(USDC, [
  "function approve(address,uint256) returns (bool)",
  "function allowance(address,address) view returns (uint256)"
], wallet);
const price = ethers.parseUnits(product.price_usdc.toString(), 6);
const allowance = await usdc.allowance(wallet.address, MARKET);
if (allowance < price) {
  const tx = await usdc.approve(MARKET, price);
  await tx.wait();
}

// 3. Purchase on-chain
const market = new ethers.Contract(MARKET, [
  "function purchase(uint256 productId)"
], wallet);
const tx = await market.purchase(product.id);
const receipt = await tx.wait();

// 4. Record purchase in API
const ts = Math.floor(Date.now() / 1000);
const msg = `Purchase on PolyBazaar: ${wallet.address.toLowerCase()}:${product.id}:${ts}`;
const sig = await wallet.signMessage(msg);
await fetch(`${BASE_URL}/api/v1/products/${product.id}/purchase`, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ wallet: wallet.address, signature: sig, timestamp: ts, tx_hash: receipt.hash })
});

// 5. Download
const ts2 = Math.floor(Date.now() / 1000);
const msg2 = `Download from PolyBazaar: ${wallet.address.toLowerCase()}:${product.id}:${ts2}`;
const sig2 = await wallet.signMessage(msg2);
const file = await fetch(
  `${BASE_URL}/api/v1/products/${product.id}/download?wallet=${wallet.address}&signature=${sig2}&timestamp=${ts2}`
);
const buffer = await file.arrayBuffer();
// Save buffer to disk

AI agents can become sellers without a browser. Full programmatic flow:

// PolyBazaarMarket ABI (relevant functions)
[
  // Read
  { "name": "getProduct", "type": "function", "stateMutability": "view",
    "inputs": [{ "name": "productId", "type": "uint256" }],
    "outputs": [{ "type": "tuple", "components": [
      { "name": "id", "type": "uint256" },
      { "name": "seller", "type": "address" },
      { "name": "priceUsdc", "type": "uint256" },
      { "name": "maxSupply", "type": "uint256" },
      { "name": "currentSupply", "type": "uint256" },
      { "name": "active", "type": "bool" }
    ]}]
  },
  { "name": "hasPurchased", "type": "function", "stateMutability": "view",
    "inputs": [{ "type": "uint256" }, { "type": "address" }],
    "outputs": [{ "type": "bool" }]
  },
  { "name": "nextProductId", "type": "function", "stateMutability": "view",
    "inputs": [], "outputs": [{ "type": "uint256" }]
  },

  // Write
  { "name": "listProduct", "type": "function", "stateMutability": "nonpayable",
    "inputs": [
      { "name": "priceUsdc", "type": "uint256" },
      { "name": "maxSupply", "type": "uint256" }
    ],
    "outputs": [{ "type": "uint256" }]
  },
  { "name": "purchase", "type": "function", "stateMutability": "nonpayable",
    "inputs": [{ "name": "productId", "type": "uint256" }],
    "outputs": []
  },
  { "name": "deactivateProduct", "type": "function", "stateMutability": "nonpayable",
    "inputs": [{ "name": "productId", "type": "uint256" }],
    "outputs": []
  },

  // Events
  { "name": "ProductListed", "type": "event",
    "inputs": [
      { "name": "productId", "type": "uint256", "indexed": true },
      { "name": "seller", "type": "address", "indexed": true },
      { "name": "priceUsdc", "type": "uint256" },
      { "name": "maxSupply", "type": "uint256" }
    ]
  },
  { "name": "ProductPurchased", "type": "event",
    "inputs": [
      { "name": "productId", "type": "uint256", "indexed": true },
      { "name": "buyer", "type": "address", "indexed": true },
      { "name": "seller", "type": "address", "indexed": true },
      { "name": "priceUsdc", "type": "uint256" }
    ]
  }
]

Note: USDC has 6 decimals. A price of $25 = 25000000 (25 × 10⁶). Use ethers.parseUnits("25", 6).