This guide shows you how to enable AI agents to programmatically create and complete USDC transactions for goods or services on Base using Coinbase Commerce and AgentKit.

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Overview

With this guide, you’ll learn how to:

  • Integrate Coinbase Commerce: Create orders and enable USDC payments on Base. Coinbase Commerce offers order tracking, reporting, webhook notifications, and built-in business tools that streamline payment management.
  • Add AgentKit Tools: Extend agents with the ability to handle charges and payments programmatically.

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Step 1. Prerequisites

Before getting started:

  1. Install AgentKit and its dependencies.
  2. Sign up for Coinbase Commerce.
  3. Obtain a Commerce API key and set it as an environment variable (COINBASE_COMMERCE_KEY).
  4. Ensure the wallet linked to your agent is connected to Base Mainnet.

Note: The AgentKit Quickstart provides a more detailed getting-started flow.

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Step 2. Add AgentKit and Agentic Commerce SDK

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Install Required Packages

npm install @agentkit/core @cdp/agentic-commerce-sdk

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Update Your Chatbot File

Integrate the Agentic Commerce SDK with AgentKit by adding the following components.

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Step 3: Enable Coinbase Commerce Interactions

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Define Constants

Add these constants to define Coinbase Commerce endpoints and your project ID:

const COMMERCE_API_URL = "https://api.commerce.coinbase.com/charges";
const ONRAMP_BASE_URL = "https://pay.coinbase.com/buy/select-asset";
const PROJECT_ID = "YOUR-PROJECT-ID";

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Create Charge Schema

Define a schema for charge requests:

interface ChargeRequest {
  name: string;
  description: string;
  pricing_type: string;
  local_price: {
    amount: string;
    currency: string;
  };
}

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Implement createCharge Function

Add the following function to enable charge creation:

async function createCharge(
  wallet: Wallet,
  args: {
    name: string;
    description: string;
    amount: string;
    currency: string;
    pricing_type: "fixed_price" | "no_price";
  },

): Promise<string> {
  const params: ChargeRequest = {
    name: args.name,
    description: args.description,
    pricing_type: args.pricing_type,
    local_price: {
      amount: args.amount,
      currency: args.currency,
    },
  };

  const response = await fetch(COMMERCE_API_URL, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "X-CC-Api-Key": process.env.COINBASE_COMMERCE_KEY || "",
    },
    body: JSON.stringify(params),
  });

  if (!response.ok) {
    throw new Error(`Failed to create charge: \${response.statusText}`);
  }

  const data = await response.json();
  return `Successfully created charge:
    Name: \${data.data.name}
    Description: \${data.data.description}
    Amount: \${data.data.pricing.local.amount} \${data.data.pricing.local.currency}
    Hosted URL: \${data.data.hosted_url}`;
}

Add a function to generate Coinbase Onramp links for purchasing crypto:

async function createOnrampLink(
  wallet: Wallet,
  args: { blockchain: string },
): Promise<string> {
  const address = (await wallet.getDefaultAddress()).getId();

  if (wallet.getNetworkId() == "base-sepolia") {
    return "Error: Wallet is not on Base Mainnet, use a faucet instead.";
  }

  const addressesObj = { [address.toString()]: [args.blockchain] };

  const onrampUrl = new URL(ONRAMP_BASE_URL);
  onrampUrl.searchParams.append("appId", PROJECT_ID);
  onrampUrl.searchParams.append("addresses", JSON.stringify(addressesObj));

  return `Generated Coinbase Onramp Link:
    URL: \${onrampUrl.toString()}
    Wallet Address: \${address}
    Blockchain: \${args.blockchain}`;
}

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Step 5: Add Tools to AgentKit

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Define Tool Prompts

const CREATE_CHARGE_PROMPT = `
This tool creates a new charge using the Coinbase Commerce API.
Use this to create a payment request or invoice.
`;
const CREATE_ONRAMP_LINK_PROMPT = `
This tool generates a Coinbase Onramp link for crypto purchases sent to a wallet.
`;

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Add Tools to AgentKit

const createChargeTool = new CdpTool(
  {
    name: "create_charge",
    description: CREATE_CHARGE_PROMPT,
    argsSchema: CreateChargeInput,
    func: createCharge,
  },
  agentkit,
);

const createOnrampLinkTool = new CdpTool(
  {
    name: "create_onramp_link",
    description: CREATE_ONRAMP_LINK_PROMPT,
    argsSchema: CreateOnrampLinkInput,
    func: createOnrampLink,
  },
  agentkit,
);

tools.push(createChargeTool, createOnrampLinkTool);

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Step 6: Create an Order API

Define an API endpoint for order creation:

app.post('/create-order', async (req, res) => {
  const { items, deliveryAddress, totalAmount } = req.body;

  if (!items || !deliveryAddress || !totalAmount) {
    return res.status(400).json({ error: "Missing order details" });
  }

  const orderId = `order-\${Date.now()}`;
  // Save order to the database (implementation not shown)
  
  res.json({ success: true, orderId, totalAmount });
});

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Step 7: Integrate and Test

  1. Start your application.
  2. Use the agent to:
    • Create an order.
    • Generate a Coinbase Commerce charge using createCharge.
    • Pay the charge programmatically or share the checkout link.

See Also: