agentgatepay-sdk

Official JavaScript/TypeScript SDK for AgentGatePay - Secure multi-chain cryptocurrency payment gateway for AI agents and autonomous systems.

Features

• 5-minute integration - From signup to first payment in under 5 minutes
• Full TypeScript support - Complete type definitions with IntelliSense
• Web3 integration - Built-in ethers.js helpers for blockchain payments
• Multi-chain - Support for Ethereum, Base, Polygon, and Arbitrum
• Multi-token - USDC, USDT, and DAI
• Webhooks - Real-time payment notifications with HMAC verification
• Analytics - Built-in revenue and spending tracking
• Zero dependencies (except axios) - Lightweight and fast

Installation

npm install agentgatepay-sdk

Optional (for Web3 features):

npm install ethers@^6.0.0

Quick Start

🔥 NEW: ConfigLoader - Simplify integration with automatic mandate management! See ConfigLoader section.

For AI Agents (Making Payments)

Option 1: With ConfigLoader (Recommended - No-Code Mandate Management)

import { AgentPayGW, ConfigLoader } from 'agentgatepay-sdk';

// 1. Load configuration (secrets from environment variables)
const configLoader = new ConfigLoader('./agentpay.config.json');
const client = new AgentPayGW({ apiKey: configLoader.getApiKey() });

// 2. Get valid mandate (auto-created if needed)
const mandateToken = await configLoader.ensureMandateValid(client);

// 3. Submit payment
const payment = await client.payments.submitTxHash(mandateToken, '0x...');
console.log(`Payment ${payment.status}: $${payment.amountUsd}`);

Option 2: Manual (Full Control)

import { AgentPayGW } from 'agentgatepay-sdk';

const client = new AgentPayGW({
  apiKey: 'pk_live_...', // Optional but recommended
  agentId: 'my-ai-agent'
});

// 1. Issue mandate manually
const mandate = await client.mandates.issue(
  '[email protected]', // Subject
  100,                 // Budget: $100 USD
  '*',                 // Scope: all resources
  1440                 // TTL: 24 hours
);

// 2. Submit payment
const payment = await client.payments.submitTxHash(
  mandate.mandateToken,
  '0x...' // Your blockchain transaction hash
);

console.log(`Payment ${payment.status}: $${payment.amountUsd}`);

For Merchants (Accepting Payments)

import { AgentPayGW } from 'agentgatepay-sdk';

const client = new AgentPayGW({
  apiKey: 'pk_live_...', // Required for merchant features
});

// 1. Verify payment
const verification = await client.payments.verify('0x...');
console.log(`Valid: ${verification.isValid}, Amount: $${verification.amountUsd}`);

// 2. Setup webhook
const webhook = await client.webhooks.create(
  'https://myserver.com/webhook',
  ['payment.completed', 'payment.failed'],
  'webhook-secret-123'
);

// 3. Get revenue analytics
const revenue = await client.analytics.getRevenue('2025-11-01', '2025-11-07');
console.log(`Total revenue: $${revenue.totalRevenueUsd}`);

Documentation

Table of Contents

• ConfigLoader (Automatic Mandate Management)
• Authentication
• Mandates (AP2)
• Payments (x402)
• Webhooks
• Analytics
• Error Handling
• Web3 Integration
• TypeScript Types

ConfigLoader (Automatic Mandate Management)

ConfigLoader simplifies integration by:

• ✅ Loading configuration from JSON file (safe to commit)
• ✅ Loading secrets from environment variables (never from JSON!)
• ✅ Auto-creating mandates on first use
• ✅ Auto-renewing mandates when budget exhausted or expired
• ✅ Perfect for AI tools, no-code platforms, and production apps

Setup

1. Create configuration file (public settings - safe to commit):

// agentpay.config.json
{
  "agentId": "[email protected]",
  "mandate": {
    "budgetUsd": 100,
    "ttlMinutes": 10080
  }
}

2. Set environment variables (secrets - NEVER commit):

export AGENTPAY_API_KEY=pk_live_...
export AGENTPAY_WALLET_PRIVATE_KEY=0x...

3. Use ConfigLoader:

import { AgentPayGW, ConfigLoader } from 'agentgatepay-sdk';

// Load configuration
const configLoader = new ConfigLoader('./agentpay.config.json');
const client = new AgentPayGW({ apiKey: configLoader.getApiKey() });

// Get valid mandate (auto-creates if needed)
const mandateToken = await configLoader.ensureMandateValid(client);

// Make payments - ConfigLoader handles mandate lifecycle automatically!
const payment = await client.payments.submitTxHash(mandateToken, '0x...');

Security Best Practices

✅ DO:

• Store configuration in JSON file (agentId, budget, TTL)
• Store secrets in environment variables (API key, wallet private key)
• Add .env to .gitignore
• Use separate agent wallet with limited funds ($10-20)

❌ DON'T:

• Put API keys or private keys in JSON files
• Commit .env files to Git
• Use main wallet for agents (security risk!)
• Hardcode secrets in code

Configuration Options

{
  "agentId": "[email protected]",
  "mandate": {
    "budgetUsd": 100,           // Required: Budget in USD
    "ttlMinutes": 10080,        // Optional: Time-to-live (default: 30 days)
    "scope": "resource.read payment.execute"  // Required: Permissions
  }
  // NOTE: Chain/token NOT configured here!
  // Gateway automatically detects from merchant's 402 response
  // Supports: Ethereum, Base, Polygon, Arbitrum
  // Supports: USDC, USDT, DAI (see table above for chain/token matrix)
}

Why no chain/token config?

• Merchant specifies chain/token in 402 response
• Gateway automatically routes to correct network
• Gateway uses correct RPC endpoint and contract address
• Agent doesn't need blockchain knowledge!

Auto-Renewal

ConfigLoader automatically renews mandates when:

1. Budget exhausted (< $0.01 remaining)
2. Mandate expired (past TTL)
3. Mandate invalid (verification fails)

Just call ensureMandateValid() before each payment - ConfigLoader handles the rest!

Example

See examples/config-loader-example.ts for complete working example.

Authentication

Sign Up

const signup = await client.auth.signup(
  '[email protected]',
  'SecurePassword123',
  'agent' // 'agent' | 'merchant' | 'both'
);

console.log(signup.apiKey); // Save this! Shown only once
client.setApiKey(signup.apiKey); // Update client

Add Wallet Address

await client.auth.addWallet('base', '0x742d35...');

Manage API Keys

// Create new API key
const newKey = await client.auth.createAPIKey('Production Server');
console.log(newKey.apiKey); // Save this!

// List all keys
const keys = await client.auth.listAPIKeys();

// Revoke key
await client.auth.revokeAPIKey('key_abc123');

Mandates (AP2)

Issue Mandate

const mandate = await client.mandates.issue(
  '[email protected]', // Subject
  100,                 // Budget in USD
  '*',                 // Scope (optional, defaults to '*')
  43200                // TTL in minutes (optional, defaults to 30 days)
);

console.log(mandate.mandateToken); // Use this in payment requests

Verify Mandate

const verification = await client.mandates.verify(mandateToken);

if (verification.valid) {
  console.log(`Budget remaining: $${verification.payload.budget_remaining}`);
} else {
  console.error(verification.error);
}

Check Remaining Budget

const remaining = await client.mandates.checkBudget(mandateToken);
console.log(`Budget remaining: $${remaining}`);

Payments (x402)

Submit Payment with Transaction Hash

const payment = await client.payments.submitTxHash(
  mandateToken,
  '0x1234...', // Blockchain transaction hash
  'base',      // Chain (optional, defaults to 'base')
  'USDC'       // Token (optional, defaults to 'USDC')
);

console.log(payment.status);        // 'completed' | 'pending' | 'failed'
console.log(payment.budgetRemaining); // Remaining mandate budget

Pay with ethers.js Wallet

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://mainnet.base.org');
const wallet = new ethers.Wallet(privateKey, provider);

const payment = await client.payments.payWithWallet(
  mandateToken,
  wallet,
  '0x742d35...', // Recipient address
  0.01,          // Amount in USD
  'base',        // Chain
  'USDC'         // Token
);

console.log(`Payment sent: ${payment.txHash}`);

Verify Payment (Merchant)

const verification = await client.payments.verify('0x1234...');

console.log(verification.isValid);     // true/false
console.log(verification.amountUsd);   // Payment amount
console.log(verification.sender);      // Sender address
console.log(verification.chain);       // Network
console.log(verification.token);       // Token symbol

Get Payment Status

const status = await client.payments.getStatus('0x1234...');
console.log(status.status); // 'completed' | 'pending' | 'failed'

List Payments (Merchant)

const payments = await client.payments.list({
  startDate: '2025-11-01',
  endDate: '2025-11-07',
  limit: 100,
  offset: 0
});

console.log(`Found ${payments.length} payments`);

Wait for Confirmation

// Poll for transaction confirmation (useful for fast chains like Base)
const verification = await client.payments.waitForConfirmation(
  '0x1234...',
  30,    // Max attempts (default: 30)
  2000   // Interval in ms (default: 2000)
);

console.log('Transaction confirmed!');

Webhooks

Create Webhook

const webhook = await client.webhooks.create(
  'https://myserver.com/webhook',
  ['payment.completed', 'payment.failed'],
  'my-webhook-secret'
);

console.log(webhook.webhookId);

List Webhooks

const webhooks = await client.webhooks.list();

Test Webhook

await client.webhooks.test(webhookId);

Delete Webhook

await client.webhooks.delete(webhookId);

Verify Webhook Signature

// In your webhook handler
app.post('/webhook', (req, res) => {
  const signature = req.headers['x-agentpay-signature'];
  const rawBody = req.rawBody; // Raw request body as string

  try {
    const payload = client.webhooks.verifyAndParse(
      rawBody,
      signature,
      'my-webhook-secret'
    );

    console.log(`Event: ${payload.type}`);
    console.log(`Amount: $${payload.data.amountUsd}`);

    res.json({ received: true });
  } catch (error) {
    res.status(400).json({ error: 'Invalid signature' });
  }
});

Analytics

Public Analytics

const analytics = await client.analytics.getPublic();

console.log(analytics.totalTransactions);
console.log(analytics.totalVolumeUsd);
console.log(analytics.chainDistribution);

User Analytics

const myAnalytics = await client.analytics.getMe();

console.log(myAnalytics.totalAmountUsd);
console.log(myAnalytics.averageTransactionUsd);
console.log(myAnalytics.recentTransactions);

Revenue Analytics (Merchant)

const revenue = await client.analytics.getRevenue(
  '2025-11-01',
  '2025-11-07'
);

console.log(`Total revenue: $${revenue.totalRevenueUsd}`);
console.log(`Transactions: ${revenue.transactionCount}`);
console.log(`Top sender: ${revenue.topSenders[0].address}`);

Error Handling

The SDK provides specific error types for better error handling:

import {
  AgentPayGW,
  RateLimitError,
  AuthenticationError,
  InvalidTransactionError,
  MandateError
} from 'agentgatepay-sdk';

try {
  const payment = await client.payments.submitTxHash(...);
} catch (error) {
  if (error instanceof RateLimitError) {
    console.log(`Rate limited. Retry after ${error.retryAfter} seconds`);
    console.log(`Limit: ${error.limit}, Remaining: ${error.remaining}`);
  } else if (error instanceof AuthenticationError) {
    console.log('Invalid or missing API key');
  } else if (error instanceof InvalidTransactionError) {
    console.log(`Transaction error: ${error.reason}`);
  } else if (error instanceof MandateError) {
    console.log(`Mandate error: ${error.reason}`);
  } else {
    console.log(`Error: ${error.message}`);
  }
}

Web3 Integration

Using with ethers.js

The SDK provides payWithWallet() helper that handles multi-chain/token payments:

import { AgentPayGW } from 'agentgatepay-sdk';
import { ethers } from 'ethers';

const client = new AgentPayGW({ apiKey: 'pk_live_...' });

// Configure chain and token
const chain = 'base';        // Options: base, ethereum, polygon, arbitrum
const token = 'USDC';        // Options: USDC, USDT, DAI

// Initialize provider for selected chain
const provider = new ethers.JsonRpcProvider('https://mainnet.base.org');
const wallet = new ethers.Wallet(privateKey, provider);

// The SDK handles transaction building and submission
const payment = await client.payments.payWithWallet(
  mandateToken,
  wallet,
  recipientAddress,
  0.01,    // USD amount
  chain,
  token
);

Changing Chain and Token:

// Example 1: DAI on Ethereum
const provider = new ethers.JsonRpcProvider('https://eth-mainnet.public.blastapi.io');
await client.payments.payWithWallet(mandateToken, wallet, recipient, 0.01, 'ethereum', 'DAI');

// Example 2: USDT on Polygon
const provider = new ethers.JsonRpcProvider('https://polygon-rpc.com');
await client.payments.payWithWallet(mandateToken, wallet, recipient, 0.01, 'polygon', 'USDT');

// Example 3: USDC on Arbitrum
const provider = new ethers.JsonRpcProvider('https://arb1.arbitrum.io/rpc');
await client.payments.payWithWallet(mandateToken, wallet, recipient, 0.01, 'arbitrum', 'USDC');

Local Signing with ethers.js (Manual Control)

For advanced use cases where you need full control over transaction signing:

import { ethers } from 'ethers';

// Multi-chain and multi-token configuration
const TOKENS = {
  USDC: {
    decimals: 6,
    contracts: {
      base: '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913',
      ethereum: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48',
      polygon: '0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359',
      arbitrum: '0xaf88d065e77c8cC2239327C5EDb3A432268e5831'
    }
  },
  USDT: {
    decimals: 6,
    contracts: {
      ethereum: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
      polygon: '0xc2132D05D31c914a87C6611C10748AEb04B58e8F',
      arbitrum: '0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9'
    }
  },
  DAI: {
    decimals: 18,
    contracts: {
      base: '0x50c5725949A6F0c72E6C4a641F24049A917DB0Cb',
      ethereum: '0x6B175474E89094C44Da98b954EedeAC495271d0F',
      polygon: '0x8f3Cf7ad23Cd3CaDbD9735AFf958023239c6A063',
      arbitrum: '0xDA10009cBd5D07dd0CeCc66161FC93D7c9000da1'
    }
  }
};

const RPCS = {
  base: 'https://mainnet.base.org',
  ethereum: 'https://eth-mainnet.public.blastapi.io',
  polygon: 'https://polygon-rpc.com',
  arbitrum: 'https://arb1.arbitrum.io/rpc'
};

// Configure payment (change these for different chains/tokens)
const chain = 'base';           // Options: base, ethereum, polygon, arbitrum
const token = 'USDC';           // Options: USDC, USDT, DAI
const amountUsd = 0.01;         // Payment amount in USD

// Get token configuration
const tokenConfig = TOKENS[token];
const tokenAddress = tokenConfig.contracts[chain];
const decimals = tokenConfig.decimals;

// Initialize provider and wallet
const provider = new ethers.JsonRpcProvider(RPCS[chain]);
const wallet = new ethers.Wallet(privateKey, provider);

// Token contract
const erc20Abi = ['function transfer(address to, uint256 amount) returns (bool)'];
const contract = new ethers.Contract(tokenAddress, erc20Abi, wallet);

// Calculate amounts in atomic units (handles different decimals automatically)
const totalAmount = BigInt(Math.floor(amountUsd * (10 ** decimals)));
const commission = totalAmount * BigInt(5) / BigInt(1000);  // 0.5%
const merchantAmount = totalAmount - commission;

// Execute commission transfer
const tx1 = await contract.transfer(commissionAddress, commission);
await tx1.wait();

// Execute merchant transfer
const tx2 = await contract.transfer(merchantAddress, merchantAmount);
await tx2.wait();

// Submit payment to AgentGatePay
const payment = await client.payments.submitTxHash(
  mandateToken,
  tx2.hash,
  chain,
  token
);

Key Features:

• Automatically handles different decimal places (6 for USDC/USDT, 18 for DAI)
• Two-transaction model (commission + merchant)
• Works with all 4 supported blockchains
• Easily switch chains/tokens by changing 3 variables

Supported Chains & Tokens

ConfigLoader and SDK automatically work with all supported chains and tokens. The gateway handles RPC endpoints and contract addresses - you just configure budget and the agent handles the rest!

Supported Networks:

• ✅ Ethereum (Mainnet)
• ✅ Base (L2, low fees, recommended)
• ✅ Polygon (L2, low fees)
• ✅ Arbitrum (L2, low fees)

Supported Tokens:

| Token | Ethereum | Base | Polygon | Arbitrum | |-------|----------|------|---------|----------| | USDC (6 decimals) | ✅ | ✅ | ✅ | ✅ | | USDT (6 decimals) | ✅ | ❌ | ✅ | ✅ | | DAI (18 decimals) | ✅ | ✅ | ✅ | ✅ |

How It Works:

• Merchant specifies chain/token in 402 response
• Gateway automatically uses correct RPC endpoint
• Gateway handles contract addresses and decimals
• Agent doesn't need to configure anything blockchain-specific!

TypeScript Types

The SDK is written in TypeScript and provides full type definitions:

import type {
  AgentPayConfig,
  IssueMandateResponse,
  SubmitPaymentResponse,
  PaymentVerification,
  Webhook,
  RevenueAnalytics
} from 'agentgatepay-sdk';

const config: AgentPayConfig = {
  apiKey: 'pk_live_...',
  debug: true
};

Examples

See the examples directory for complete working examples:

• quickstart-agent.ts - Agent quickstart (5 minutes to first payment)
• quickstart-merchant.ts - Merchant quickstart (5 minutes to integration)
• full-payment-flow.ts - Complete flow with ethers.js
• webhook-server.ts - Express.js webhook handler

Configuration

Environment Variables

# API key (optional but recommended)
AGENTPAY_API_KEY=pk_live_...

# Agent ID (optional, defaults to 'sdk-client')
AGENTPAY_AGENT_ID=my-agent

# API URL (optional, defaults to production)
AGENTPAY_API_URL=https://api.agentgatepay.io

# Webhook secret (for webhook verification)
WEBHOOK_SECRET=my-secret-123

# Private key (for ethers.js integration)
PRIVATE_KEY=0x...

Client Options

const client = new AgentPayGW({
  apiKey: 'pk_live_...',      // API key (optional)
  agentId: 'my-agent',        // Agent ID (optional)
  apiUrl: 'https://...',      // API URL (optional)
  timeout: 30000,             // Request timeout in ms (default: 30000)
  debug: true                 // Enable debug logging (default: false)
});

Rate Limits & Security (AIF)

AIF (Agent Interaction Firewall) - The first firewall built specifically for AI agents.

Rate Limits

| User Type | Rate Limit | Benefits | |-----------|------------|----------| | Anonymous | 20 req/min | Basic access, no signup | | With Account | 100 req/min | 5x more requests, payment history, reputation tracking |

Create a free account to increase your limits:

const user = await client.auth.signup(
  '[email protected]',
  'secure_password',
  'agent' // or 'merchant' or 'both'
);
console.log(user.apiKey); // Use this for 5x rate limit!

Security Features

• ✅ Distributed rate limiting (production-grade implementation)
• ✅ Replay protection (TX-hash nonces, 24h TTL)
• ✅ Agent reputation system (0-200 score, enabled by default)
• ✅ Mandatory mandates (budget & scope enforcement)

Rate limit info is included in error messages:

catch (error) {
  if (error instanceof RateLimitError) {
    console.log(`Retry after: ${error.retryAfter} seconds`);
    console.log(`Limit: ${error.limit}`);
    console.log(`Remaining: ${error.remaining}`);
  }
}

Support

• GitHub Issues: https://github.com/AgentGatePay/agentgatepay-sdks/issues
• Examples Repository: https://github.com/AgentGatePay/agentgatepay-examples
• Email: [email protected]

License

MIT License - see LICENSE file for details

Contributing

Contributions are welcome! Please open an issue or submit a pull request.

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