> ## Documentation Index
> Fetch the complete documentation index at: https://docs.snack.money/llms.txt
> Use this file to discover all available pages before exploring further.

# Coinbase CDP SDK

> Server-side wallet management with MPC security and x402 v2

This example demonstrates integration using the **Coinbase Developer Platform (CDP) SDK** with MPC-based key management and **x402 v2**. Perfect for backend applications requiring enterprise-grade security.

## Overview

The CDP SDK provides server-side wallet management without exposing private keys. Keys are secured with Multi-Party Computation (MPC) technology. This example works with x402 v2 for both Base and Solana networks.

## Features

* ✅ **MPC-based key management** - No private keys in your code
* ✅ **Base (EVM) and Solana (SVM) network** support
* ✅ **Enterprise security** - Built by Coinbase
* ✅ **Server-side wallets** - Perfect for backends
* ✅ **Type-safe TypeScript**

## Prerequisites

* Node.js 18+
* Coinbase CDP API credentials ([Get them here](https://portal.cdp.coinbase.com/))
* USDC balance on Base or Solana
* Existing CDP wallet address (Base) or Solana account

## Installation

```bash theme={null}
npm install @coinbase/cdp-sdk axios @x402/axios @x402/evm @x402/svm viem bs58
```

## Quick Start

### 1. Get CDP Credentials

1. Visit [Coinbase Developer Platform](https://portal.cdp.coinbase.com/)
2. Create an API key
3. Save your API Key ID and Secret
4. Create a wallet and fund it with USDC on Base

### 2. Set Up Environment

Create a `.env` file:

```bash theme={null}
CDP_API_KEY_ID=your_api_key_id
CDP_API_KEY_SECRET=your_api_key_secret
CDP_WALLET_SECRET=your_wallet_secret
# For Base network
WALLET_ADDRESS=your_wallet_address
# For Solana network
SOLANA_ADDRESS=your_solana_address
# Common
RECEIVER=your_x_username
AMOUNT=0.01
```

### 3. Implement Base (EVM) Payment

Create `base-send.ts`:

```typescript theme={null}
import { CdpClient } from "@coinbase/cdp-sdk";
import axios from "axios";
import { privateKeyToAccount } from "viem/accounts";
import { x402Client, wrapAxiosWithPayment, decodePaymentResponseHeader } from "@x402/axios";
import { registerExactEvmScheme } from "@x402/evm/exact/client";

const apiKeyId = process.env.CDP_API_KEY_ID as string;
const apiKeySecret = process.env.CDP_API_KEY_SECRET as string;
const walletSecret = process.env.CDP_WALLET_SECRET as string;
const walletAddress = process.env.WALLET_ADDRESS as string;
const receiver = process.env.RECEIVER as string;
const amount = parseFloat(process.env.AMOUNT || "0.01");

async function sendPayment() {
  console.log("🚀 Starting Snack Money payment with CDP SDK (Base)\n");

  // Initialize CDP client
  const cdpClient = new CdpClient({
    apiKeyId,
    apiKeySecret,
    walletSecret,
  });
  console.log("✅ Initialized CDP client\n");

  // Export private key from CDP for x402 signing
  console.log("🔐 Exporting private key from CDP...\n");
  const privateKey = await cdpClient.evm.exportAccount({
    address: walletAddress
  });

  // Create viem account from private key
  const account = privateKeyToAccount(`0x${privateKey}`);
  console.log(`✅ Base signer created: ${account.address}\n`);

  // Create x402 client and register EVM scheme
  const x402 = new x402Client();
  registerExactEvmScheme(x402, { signer: account });
  console.log("✅ Registered EVM payment scheme\n");

  // Wrap axios with payment interceptor
  const api = wrapAxiosWithPayment(
    axios.create({ baseURL: "https://api.snack.money" }),
    x402
  );

  console.log(`💸 Sending ${amount} USDC to @${receiver} on X via Base...\n`);

  try {
    const response = await api.post("/payments/x/pay", {
      amount,
      currency: "USDC",
      receiver,
      description: "Payment via CDP SDK (Base)"
    });

    console.log("✅ Payment successful!");
    console.log("\n📊 Response:", JSON.stringify(response.data, null, 2));

    const paymentResponseHeader = response.headers["payment-response"];
    if (paymentResponseHeader) {
      const paymentResponse = decodePaymentResponseHeader(paymentResponseHeader);
      console.log("\n🔐 Payment Response Details:", JSON.stringify(paymentResponse, null, 2));
    }
  } catch (error) {
    console.error("❌ Payment failed:", error);
    throw error;
  }
}

sendPayment();
```

### 4. Implement Solana (SVM) Payment

Create `solana-send.ts`:

```typescript theme={null}
import { CdpClient } from "@coinbase/cdp-sdk";
import axios from "axios";
import { x402Client, wrapAxiosWithPayment, decodePaymentResponseHeader } from "@x402/axios";
import { registerExactSvmScheme } from "@x402/svm/exact/client";
import { createKeyPairSignerFromBytes } from "@solana/kit";
import bs58 from "bs58";

const apiKeyId = process.env.CDP_API_KEY_ID as string;
const apiKeySecret = process.env.CDP_API_KEY_SECRET as string;
const walletSecret = process.env.CDP_WALLET_SECRET as string;
const solanaAddress = process.env.SOLANA_ADDRESS as string;
const receiver = process.env.RECEIVER as string;
const amount = parseFloat(process.env.AMOUNT || "0.01");

async function sendPayment() {
  console.log("🚀 Starting Snack Money payment with CDP SDK (Solana)\n");

  // Initialize CDP client
  const cdpClient = new CdpClient({
    apiKeyId,
    apiKeySecret,
    walletSecret,
  });
  console.log("✅ Initialized CDP client\n");

  if (!solanaAddress) {
    console.error("❌ Missing SOLANA_ADDRESS in .env file!");
    console.log("\n💡 Run the create-solana-account.ts script first:");
    console.log("   npm run create-solana-account");
    process.exit(1);
  }

  console.log(`✅ Using CDP Solana account: ${solanaAddress}\n`);

  // Export private key from CDP for x402 signing
  console.log("🔐 Exporting private key from CDP...\n");
  const privateKeyBase58 = await cdpClient.solana.exportAccount({
    address: solanaAddress
  });

  // Create Solana signer from private key
  const privateKeyBytes = bs58.decode(privateKeyBase58);
  const solanaSigner = await createKeyPairSignerFromBytes(privateKeyBytes);
  console.log(`✅ Solana signer created: ${solanaSigner.address}\n`);

  // Create x402 client and register Solana scheme
  const client = new x402Client();
  registerExactSvmScheme(client, { signer: solanaSigner });
  console.log("✅ Registered Solana payment scheme\n");

  // Wrap axios with payment interceptor
  const api = wrapAxiosWithPayment(
    axios.create({ baseURL: "https://api.snack.money" }),
    client
  );

  console.log(`💸 Sending ${amount} USDC to @${receiver} on X via Solana...\n`);

  try {
    const response = await api.post("/payments/x/pay", {
      amount,
      currency: "USDC",
      receiver,
      description: "Payment via CDP SDK (Solana)"
    });

    console.log("✅ Payment successful!");
    console.log("\n📊 Response:", JSON.stringify(response.data, null, 2));

    const paymentResponseHeader = response.headers["payment-response"];
    if (paymentResponseHeader) {
      const paymentResponse = decodePaymentResponseHeader(paymentResponseHeader);
      console.log("\n🔐 Payment Response Details:", JSON.stringify(paymentResponse, null, 2));
    }
  } catch (error) {
    console.error("❌ Payment failed:", error);
    throw error;
  }
}

sendPayment();
```

### 5. Run the Example

For Base network:

```bash theme={null}
npm run base
# or
npx tsx base-send.ts
```

For Solana network:

```bash theme={null}
npm run solana
# or
npx tsx solana-send.ts
```

## Expected Output

```
🚀 Starting Snack Money payment with CDP SDK

✅ Initialized CDP client
✅ Retrieved CDP wallet
💸 Sending 0.01 USDC to @username on X...

✅ Payment successful!

📊 Response: {
  "code": 200,
  "msg": "0.01 USDC sent successfully",
  "data": {
    "txn_id": "0xabc...def",
    "amount": 0.01,
    "receipt": "https://snack.money/x/username?txn=..."
  }
}
```

## How It Works

1. **Initialize CDP**: Create CDP client with API credentials
2. **Get Wallet**: Retrieve existing wallet by address
3. **Export Key**: Export private key for transaction signing
4. **Create Account**: Convert to viem account format
5. **Wrap Axios**: Add x402 payment interceptor
6. **Send Payment**: Make payment request

## Why CDP SDK?

### Security Benefits

* **No Private Key Management**: Keys secured with MPC
* **Enterprise Grade**: Built by Coinbase
* **Compliance**: Meets regulatory requirements
* **Audit Trail**: Complete transaction history

### Best For

* Backend applications
* Enterprise deployments
* High-value transactions
* Compliance-focused apps

## Supported Platforms

Send payments to:

```typescript theme={null}
// X (Twitter)
await api.post("/payments/x/pay", { amount, receiver, currency: "USDC" });

// Farcaster
await api.post("/payments/farcaster/pay", { amount, receiver, currency: "USDC" });

// GitHub
await api.post("/payments/github/pay", { amount, receiver, currency: "USDC" });
```

## Error Handling

```typescript theme={null}
try {
  const response = await api.post("/payments/x/pay", {
    amount: 0.01,
    currency: "USDC",
    receiver: "username"
  });
  console.log("Success:", response.data);
} catch (error) {
  console.error("Payment failed:", error);
  // Handle CDP-specific errors
  if (error.message.includes("wallet not found")) {
    console.error("CDP wallet not found. Check WALLET_ADDRESS");
  }
}
```

## CDP Wallet Management

### Creating a Wallet

```typescript theme={null}
const wallet = await coinbase.createWallet({
  networkId: "base-mainnet"
});
console.log("Wallet address:", wallet.getDefaultAddress());
```

### Funding the Wallet

Transfer USDC to your wallet address on Base network before making payments.

## Full Example Repository

[View on GitHub →](https://github.com/snack-money/snack-money-examples/tree/main/cdp-sdk)

Includes:

* Complete implementation
* Environment setup
* Configuration examples
* Detailed README

## Next Steps

* [**Try x402-fetch**](/examples/fetch) - Minimal dependencies
* [**Try thirdweb**](/examples/thirdweb) - Managed infrastructure
* [**CDP Documentation**](https://docs.cdp.coinbase.com/) - Learn more about CDP

## Dependencies

```json theme={null}
{
  "dependencies": {
    "@coinbase/coinbase-sdk": "latest",
    "axios": "^1.6.0",
    "x402-axios": "latest",
    "viem": "^2.0.0"
  }
}
```

## Learn More

* [Coinbase CDP SDK Documentation](https://docs.cdp.coinbase.com/)
* [x402 Protocol](https://github.com/coinbase/x402)
* [API Reference](/api-reference/introduction)