Agentic Commerce - Buy IRL Items With USDC

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name: purch-api description: | AI-powered shopping API for product search and crypto checkout. Use this skill when: - Searching for products from Amazon and Shopify - Building shopping assistants or product recommendation features - Creating purchase orders with crypto (USDC on Solana or Base) - Integrating e-commerce checkout into applications - Signing and submitting blockchain transactions for purchases

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Purch Public API

Base URL: https://api.purch.xyz

Rate Limits

60 requests/minute per IP. Headers in every response:

X-RateLimit-Limit: Max requests per window

X-RateLimit-Remaining: Requests left

X-RateLimit-Reset: Seconds until reset

Endpoints

GET /search - Structured Product Search

Query products with filters.

curl "https://api.purch.xyz/search?q=headphones&priceMax=100"

Parameters: | Param | Type | Required | Description | |-------|------|----------|-------------| | q | string | Yes | Search query | | priceMin | number | No | Minimum price | | priceMax | number | No | Maximum price | | brand | string | No | Filter by brand | | page | number | No | Page number (default: 1) |

Response:

{
  "products": [
    {
      "id": "B0CXYZ1234",
      "title": "Sony WH-1000XM5",
      "price": 348.00,
      "currency": "USD",
      "rating": 4.8,
      "reviewCount": 15420,
      "imageUrl": "https://...",
      "productUrl": "https://amazon.com/dp/B0CXYZ1234",
      "source": "amazon"
    }
  ],
  "totalResults": 20,
  "page": 1,
  "hasMore": true
}

POST /shop - AI Shopping Assistant

Natural language product search. Returns 20+ products from both Amazon and Shopify.

curl -X POST "https://api.purch.xyz/shop" \
  -H "Content-Type: application/json" \
  -d '{"message": "comfortable running shoes under $100"}'

Request Body:

{
  "message": "comfortable running shoes under $100",
  "context": {
    "priceRange": { "min": 0, "max": 100 },
    "preferences": ["comfortable", "breathable"]
  }
}

Response:

{
  "reply": "Found 22 running shoes. Top pick: Nike Revolution 6 at $65...",
  "products": [
    {
      "asin": "B09XYZ123",
      "title": "Nike Revolution 6",
      "price": 65.00,
      "currency": "USD",
      "rating": 4.5,
      "reviewCount": 8420,
      "imageUrl": "https://...",
      "productUrl": "https://amazon.com/dp/B09XYZ123",
      "source": "amazon"
    },
    {
      "asin": "gid://shopify/p/abc123",
      "title": "Allbirds Tree Runners",
      "price": 98.00,
      "source": "shopify",
      "productUrl": "https://allbirds.com/products/tree-runners",
      "vendor": "Allbirds"
    }
  ]
}

POST /buy - Create Purchase Order

Create an order and get a transaction to sign. Chain is auto-detected from wallet format:

Solana wallet (base58): 7xKXtg2CW87d97TXJSDpbD5jBkheTqA83TZRuJosgAsU

Base/EVM wallet (0x): 0x1234567890abcdef1234567890abcdef12345678

Amazon Products (Solana):

curl -X POST "https://api.purch.xyz/buy" \
  -H "Content-Type: application/json" \
  -d '{
    "asin": "B0CXYZ1234",
    "email": "buyer@example.com",
    "walletAddress": "7xKXtg2CW87d97TXJSDpbD5jBkheTqA83TZRuJosgAsU",
    "shippingAddress": {
      "name": "John Doe",
      "line1": "123 Main St",
      "line2": "Apt 4B",
      "city": "New York",
      "state": "NY",
      "postalCode": "10001",
      "country": "US",
      "phone": "+1-555-123-4567"
    }
  }'

Amazon Products (Base):

curl -X POST "https://api.purch.xyz/buy" \
  -H "Content-Type: application/json" \
  -d '{
    "asin": "B0CXYZ1234",
    "email": "buyer@example.com",
    "walletAddress": "0x1234567890abcdef1234567890abcdef12345678",
    "shippingAddress": {
      "name": "John Doe",
      "line1": "123 Main St",
      "city": "New York",
      "state": "NY",
      "postalCode": "10001",
      "country": "US"
    }
  }'

Shopify Products - Use productUrl AND variantId:

curl -X POST "https://api.purch.xyz/buy" \
  -H "Content-Type: application/json" \
  -d '{
    "productUrl": "https://store.com/products/item-name",
    "variantId": "41913945718867",
    "email": "buyer@example.com",
    "walletAddress": "7xKXtg2CW87d97TXJSDpbD5jBkheTqA83TZRuJosgAsU",
    "shippingAddress": {
      "name": "John Doe",
      "line1": "123 Main St",
      "city": "New York",
      "state": "NY",
      "postalCode": "10001",
      "country": "US"
    }
  }'

Response:

{
  "orderId": "550e8400-e29b-41d4-a716-446655440000",
  "status": "awaiting-payment",
  "serializedTransaction": "NwbtPCP62oXk5fmSrgT...",
  "product": {
    "title": "Sony WH-1000XM5",
    "imageUrl": "https://...",
    "price": { "amount": "348.00", "currency": "usdc" }
  },
  "totalPrice": { "amount": "348.00", "currency": "usdc" },
  "checkoutUrl": "https://www.crossmint.com/checkout/550e8400..."
}

CLI Scripts

This skill includes ready-to-use CLI scripts for all endpoints. Available in Python and TypeScript/Bun.

Dependencies (Solana):

# Python
pip install solana solders base58
TypeScript/Bun
bun add @solana/web3.js bs58

Dependencies (Base/EVM):

# TypeScript/Bun
bun add viem

Search Products

# Python
python scripts/search.py "wireless headphones" --price-max 100
python scripts/search.py "running shoes" --brand Nike --page 2
TypeScript
bun run scripts/search.ts "wireless headphones" --price-max 100

AI Shopping Assistant

# Python
python scripts/shop.py "comfortable running shoes under $100"
TypeScript
bun run scripts/shop.ts "wireless headphones with good noise cancellation"

Create Order (without signing)

# Amazon by ASIN
python scripts/buy.py --asin B0CXYZ1234 --email buyer@example.com \
  --wallet 7xKXtg... --address "John Doe,123 Main St,New York,NY,10001,US"
Shopify product
bun run scripts/buy.ts --url "https://store.com/products/item" --variant 41913945718867 \
  --email buyer@example.com --wallet 7xKXtg... --address "John Doe,123 Main St,NYC,NY,10001,US"

Address format: Name,Line1,City,State,PostalCode,Country[,Line2][,Phone]

Create Order AND Sign Transaction (Solana)

End-to-end purchase flow - creates order and signs/submits the Solana transaction:

# Python
python scripts/buy_and_sign.py --asin B0CXYZ1234 --email buyer@example.com \
  --wallet 7xKXtg... --private-key 5abc123... \
  --address "John Doe,123 Main St,New York,NY,10001,US"
TypeScript
bun run scripts/buy_and_sign.ts --url "https://store.com/products/item" --variant 41913945718867 \
  --email buyer@example.com --wallet 7xKXtg... --private-key 5abc123... \
  --address "John Doe,123 Main St,NYC,NY,10001,US"

Create Order AND Sign Transaction (Base)

End-to-end purchase flow using Base/EVM wallet:

bun run scripts/buy_and_sign_base.ts --asin B0CXYZ1234 --email buyer@example.com \
  --wallet 0x1234567890abcdef1234567890abcdef12345678 \
  --private-key 0xabc123... \
  --address "John Doe,123 Main St,New York,NY,10001,US"

Sign Transaction Only (Solana)

If you already have a serializedTransaction from the /buy endpoint:

# Python
python scripts/sign_transaction.py "" ""
TypeScript
bun run scripts/sign_transaction.ts "" ""

Sign Transaction Only (Base)

bun run scripts/sign_transaction_base.ts "" ""

Output (Solana):

✅ Transaction successful!
   Signature: 5UfgJ3vN...
   Explorer:  https://solscan.io/tx/5UfgJ3vN...

Output (Base):

✅ Transaction successful!
   Hash:     0x1234...
   Explorer: https://basescan.org/tx/0x1234...

Signing Transactions Programmatically

For custom integrations without using the bundled scripts:

JavaScript/TypeScript

import { Connection, Transaction, clusterApiUrl } from "@solana/web3.js";
import bs58 from "bs58";
async function signAndSendTransaction(
  serializedTransaction: string,
  wallet: { signTransaction: (tx: Transaction) => Promise }
) {
  // Decode the base58 transaction
  const transactionBuffer = bs58.decode(serializedTransaction);
  const transaction = Transaction.from(transactionBuffer);
  // Sign with user's wallet (e.g., Phantom, Solflare)
  const signedTransaction = await wallet.signTransaction(transaction);
  // Send to Solana network
  const connection = new Connection(clusterApiUrl("mainnet-beta"));
  const signature = await connection.sendRawTransaction(
    signedTransaction.serialize()
  );
  // Confirm transaction
  await connection.confirmTransaction(signature, "confirmed");
  return signature;
}

React with Wallet Adapter

import { useWallet, useConnection } from "@solana/wallet-adapter-react";
import { Transaction } from "@solana/web3.js";
import bs58 from "bs58";
function CheckoutButton({ serializedTransaction }: { serializedTransaction: string }) {
  const { signTransaction, publicKey } = useWallet();
  const { connection } = useConnection();
  const handlePayment = async () => {
    if (!signTransaction || !publicKey) {
      throw new Error("Wallet not connected");
    }
    // Decode and sign
    const tx = Transaction.from(bs58.decode(serializedTransaction));
    const signed = await signTransaction(tx);
    // Send and confirm
    const sig = await connection.sendRawTransaction(signed.serialize());
    await connection.confirmTransaction(sig, "confirmed");
    console.log("Payment complete:", sig);
  };
  return Pay with USDC;
}

Python (with solana-py)

import base58
from solana.rpc.api import Client
from solana.transaction import Transaction
from solders.keypair import Keypair
def sign_and_send(serialized_tx: str, keypair: Keypair) -> str:
    # Decode base58 transaction
    tx_bytes = base58.b58decode(serialized_tx)
    transaction = Transaction.deserialize(tx_bytes)
    # Sign
    transaction.sign(keypair)
    # Send
    client = Client("https://api.mainnet-beta.solana.com")
    result = client.send_transaction(transaction)
    return result.value  # transaction signature

Signing Base/EVM Transactions

For Base chain orders, the serializedTransaction is an EVM transaction that needs to be signed with an EVM wallet.

TypeScript with viem

import { createWalletClient, http, parseTransaction } from "viem";
import { base } from "viem/chains";
import { privateKeyToAccount } from "viem/accounts";
async function signAndSendBaseTransaction(
  serializedTransaction: string,
  privateKey: 0x${string}
) {
  const account = privateKeyToAccount(privateKey);
  const client = createWalletClient({
    account,
    chain: base,
    transport: http(),
  });
  // Parse and send the serialized transaction
  const tx = parseTransaction(serializedTransaction as 0x${string});
  const hash = await client.sendTransaction(tx);
  console.log("Transaction hash:", hash);
  console.log("Explorer: https://basescan.org/tx/" + hash);
  return hash;
}

React with wagmi

import { useSendTransaction } from "wagmi";
import { parseTransaction } from "viem";
function CheckoutButton({ serializedTransaction }: { serializedTransaction: string }) {
  const { sendTransaction } = useSendTransaction();
  const handlePayment = async () => {
    const tx = parseTransaction(serializedTransaction as 0x${string});
    sendTransaction(tx);
  };
  return Pay with USDC on Base;
}

Complete Checkout Flow (Solana)

// 1. Search for products
const searchResponse = await fetch("https://api.purch.xyz/shop", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ message: "wireless headphones under $100" })
});
const { products, reply } = await searchResponse.json();
// 2. User selects a product, create order (Solana wallet)
const orderResponse = await fetch("https://api.purch.xyz/buy", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    asin: products[0].asin,
    email: "buyer@example.com",
    walletAddress: wallet.publicKey.toBase58(), // Solana address
    shippingAddress: {
      name: "John Doe",
      line1: "123 Main St",
      city: "New York",
      state: "NY",
      postalCode: "10001",
      country: "US"
    }
  })
});
const { orderId, serializedTransaction, checkoutUrl } = await orderResponse.json();
// 3. Sign and send Solana transaction
const tx = Transaction.from(bs58.decode(serializedTransaction));
const signed = await wallet.signTransaction(tx);
const signature = await connection.sendRawTransaction(signed.serialize());
await connection.confirmTransaction(signature, "confirmed");
console.log(Order ${orderId} paid. Tx: ${signature});

Complete Checkout Flow (Base)

import { parseTransaction } from "viem";
// 1. Search for products
const searchResponse = await fetch("https://api.purch.xyz/shop", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ message: "wireless headphones under $100" })
});
const { products } = await searchResponse.json();
// 2. User selects a product, create order (EVM wallet)
const orderResponse = await fetch("https://api.purch.xyz/buy", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    asin: products[0].asin,
    email: "buyer@example.com",
    walletAddress: "0x1234...", // Base/EVM address - chain auto-detected
    shippingAddress: {
      name: "John Doe",
      line1: "123 Main St",
      city: "New York",
      state: "NY",
      postalCode: "10001",
      country: "US"
    }
  })
});
const { orderId, serializedTransaction } = await orderResponse.json();
// 3. Sign and send Base transaction
const tx = parseTransaction(serializedTransaction as 0x${string});
const hash = await walletClient.sendTransaction(tx);
console.log(Order ${orderId} paid. Tx: ${hash});

Fallback: Browser Checkout

If wallet signing fails or isn't available, redirect to checkoutUrl for browser-based payment:

if (!wallet.connected) {
  window.open(checkoutUrl, "_blank");
}

Error Handling

All endpoints return errors as:

{
  "code": "VALIDATION_ERROR",
  "message": "Invalid email format",
  "details": { "field": "email" }
}

Common error codes:

VALIDATION_ERROR (400) - Invalid request parameters

NOT_FOUND (404) - Product not found

RATE_LIMITED (429) - Too many requests

INTERNAL_ERROR (500) - Server error