SDK Examples

Explore different ways to integrate Snack Money’s x402 v2 payment API into your application. Each example demonstrates a complete implementation with a different SDK or infrastructure provider.

Available Examples

A2A Protocol

Agent-to-Agent protocol implementation with X402 extension.

Best for: AI agents and autonomous systems
Networks: Base (EVM), Solana (SVM)
Complexity: Simple
Features: Agent discovery, JSON-RPC 2.0, async payments

// Discover agent capabilities
GET https://api.snack.money/a2a/.well-known/agent-card

// Send payment via JSON-RPC
POST https://api.snack.money/a2a
{
  "jsonrpc": "2.0",
  "method": "snack-money.pay.twitter",
  "params": {
    "receiver": "username",
    "amount": 0.01
  }
}

View full example →

x402-axios (v2)

The simplest integration using axios with x402 v2 payment client.

Best for: Most web applications
Networks: Base (EVM), Solana (SVM)
Complexity: Simple
Dependencies: Minimal

import { x402Client, wrapAxiosWithPayment } from "@x402/axios";
import { registerExactEvmScheme } from "@x402/evm/exact/client";

const client = new x402Client();
registerExactEvmScheme(client, { signer: account });

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

await api.post("/payments/x/pay", {
  amount: 0.01,
  currency: "USDC",
  receiver: "username"
});

View full example →

Coinbase CDP SDK

Server-side wallet management with MPC security.

Best for: Backend applications, enterprises
Networks: Base (EVM), Solana (SVM)
Complexity: Moderate
Key management: MPC-based, no private keys needed

const privateKey = await cdpClient.evm.exportAccount({ address: walletAddress });
const account = privateKeyToAccount(`0x${privateKey}`);

const client = new x402Client();
registerExactEvmScheme(client, { signer: account });

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

View full example →

x402-fetch (v2)

Minimal integration using x402 v2 with axios under the hood.

Best for: Node.js apps, minimal footprint
Networks: Base (EVM), Solana (SVM)
Complexity: Simple
Dependencies: Minimal

import { x402Client, wrapAxiosWithPayment } from "@x402/axios";
import { registerExactEvmScheme } from "@x402/evm/exact/client";

const client = new x402Client();
registerExactEvmScheme(client, { signer: account });

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

View full example →

thirdweb

Managed infrastructure with thirdweb’s payment API.

Best for: Apps using thirdweb ecosystem
Network: Base (EVM)
Complexity: Moderate
Key management: Managed by thirdweb

const wallet = new PrivateKeyWallet({
  client,
  privateKey: process.env.THIRDWEB_PRIVATE_KEY
});

// Use with x402 wrapper

View full example →

Crossmint Smart Wallets

Smart contract wallets with account abstraction.

Best for: Apps needing smart wallet features
Network: Base (EVM)
Complexity: Moderate
Features: Account abstraction, smart wallets

const wallet = CrossmintSmartWallet.build({
  config: { chain: "base" },
  signer: { type: "DEVELOPER_CONTROLLED" }
});

// Use with viem-compatible interface

View full example →

Comparison Matrix

Example	Network(s)	Private Keys	Complexity	Best For
A2A	Base, Solana	Direct	⭐ Simple	AI agents
axios	Base, Solana	Direct	⭐ Simple	Most apps
CDP SDK	Base, Solana	MPC managed	⭐⭐ Moderate	Enterprises
fetch	Base, Solana	Direct	⭐ Simple	Node.js apps
thirdweb	Base	Managed	⭐⭐ Moderate	thirdweb users
Crossmint	Base	Smart wallet	⭐⭐ Moderate	Smart wallets

Quick Start

Each example follows the same structure:

Clone or copy the example code
Install dependencies: npm install
Configure environment: Copy .env.example to .env
Add credentials: Private key and receiver username
Run: npm run dev

Common Prerequisites

All examples require:

Node.js 18+
USDC balance on the target network
Receiver username: Use your own X account for testing

Supported Platforms

All examples support sending payments to:

X (Twitter) - /payments/x/pay
Farcaster - /payments/farcaster/pay
GitHub - /payments/github/pay

Network Support

Network	axios	CDP SDK	fetch	thirdweb	Crossmint
Base	✅	✅	✅	✅	✅
Solana	✅	✅	✅	❌	❌

Choosing the Right Example

Use A2A if you’re:

Building AI agents or autonomous systems
Need agent discovery capabilities
Want JSON-RPC based communication
Implementing agent-to-agent payments

Use axios if you want:

Simplest integration
Familiar HTTP client
Minimal setup
Both Base and Solana support

Use CDP SDK if you want:

Enterprise-grade security
No direct private key management
Server-side wallets
Both Base and Solana support

Use fetch if you want:

Minimal dependencies
Simple integration
Both Base and Solana support

Use thirdweb if you’re:

Already using thirdweb
Building on their infrastructure
Need their ecosystem tools

Use Crossmint if you need:

Smart contract wallets
Account abstraction
Advanced wallet features

Integration Steps

1. Choose Your Example

Pick the example that matches your stack and requirements.

2. Set Up Environment

All examples use environment variables for configuration:

# For EVM networks (Base)
EVM_PRIVATE_KEY=0x...
RECEIVER=your_x_username
AMOUNT=0.01

# For Solana network (SVM)
SVM_PRIVATE_KEY=base58_key...

# Additional keys for specific examples
ANTHROPIC_API_KEY=sk-ant-...  # For AI features
CDP_API_KEY_ID=...            # For CDP SDK
THIRDWEB_SECRET_KEY=...       # For thirdweb
CROSSMINT_API_KEY=...         # For Crossmint

3. Install Dependencies

cd examples/<example-name>
npm install

4. Run the Example

npm run dev

Testing Tips

Start small: Use 0.01 USDC (1 cent) for initial tests
Test on yourself: Send to your own X account
Check balance: Ensure sufficient USDC + gas fees
Verify receipt: Click the receipt URL to confirm payment

Example Output

All examples produce similar output:

🚀 Starting Snack Money payment example

✅ Signer/wallet created
💸 Sending 0.01 USDC to @username on X...

✅ Payment successful!

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

Source Code

All example source code is available on GitHub: View examples repository → Each example includes:

Complete TypeScript implementation
Environment configuration
README with setup instructions
package.json with dependencies

Next Steps

Choose an example that fits your needs
Follow the guide for that specific example
Integrate into your application
Refer to API docs for advanced usage

Additional Resources

Getting Started - Quick API overview
x402 Protocol - Understanding x402
API Reference - Complete API docs
CLI Tool - Command-line interface

Getting Help

GitHub Issues: Report bugs or request features
Documentation: Comprehensive guides for each example
API Support: Contact via snack.money

Introduction

CLI

​Available Examples

​A2A Protocol

​x402-axios (v2)

​Coinbase CDP SDK

​x402-fetch (v2)

​thirdweb

​Crossmint Smart Wallets

​Comparison Matrix

​Quick Start

​Common Prerequisites

​Supported Platforms

​Network Support

​Choosing the Right Example

​Use A2A if you’re:

​Use axios if you want:

​Use CDP SDK if you want:

​Use fetch if you want:

​Use thirdweb if you’re:

​Use Crossmint if you need:

​Integration Steps

​1. Choose Your Example

​2. Set Up Environment

​3. Install Dependencies

​4. Run the Example

​Testing Tips

​Example Output

​Source Code

​Next Steps

​Additional Resources

​Getting Help

Available Examples

A2A Protocol

x402-axios (v2)

Coinbase CDP SDK

x402-fetch (v2)

thirdweb

Crossmint Smart Wallets

Comparison Matrix

Quick Start

Common Prerequisites

Supported Platforms

Network Support

Choosing the Right Example

Use A2A if you’re:

Use axios if you want:

Use CDP SDK if you want:

Use fetch if you want:

Use thirdweb if you’re:

Use Crossmint if you need:

Integration Steps

1. Choose Your Example

2. Set Up Environment

3. Install Dependencies

4. Run the Example

Testing Tips

Example Output

Source Code

Next Steps

Additional Resources

Getting Help