PipeGate Client SDK Documentation

Overview

PipeGate SDK enables developers to interact with the PipeGate protocol for API monetization using payment channels with stablecoins. This guide covers SDK installation, configuration, and usage for both API consumers and providers.

Installation

npm install pipegate-sdk
# or
yarn add pipegate-sdk
# or
bun add pipegate-sdk

Basic Setup

1. Create a .env file in your project root:

WALLET_PRIVATE_KEY=your_private_key_here

2. Initialize the SDK:

import { ClientInterceptor } from "pipegate-sdk";

// Create SDK instance
const pipeGate = new ClientInterceptor();
await pipeGate.initialize();

Core Features

Creating a Payment Channel

To start using an API, first create a payment channel & add it:

const channelParams = {
  recipient: "0x...", // API provider's address
  duration: 2592000, // Channel duration in seconds (30 days)
  tokenAddress: "0x...", // Payment token address (e.g., USDC)
  amount: "100", // Amount in tokens to deposit (in decimals ) 100 USDC
};

const channel = await pipeGate.createPaymentChannel(channelParams);

await pipeGate.addNewChannel(channel.channelId, channel);

Making API Calls with Payment Channel method

Using with Axios

1. Create an Axios instance with PipeGate interceptors:

import axios from "axios";

const api = axios.create({
  baseURL: "https://api.example.com",
});

// Add request interceptor for automatic signing
api.interceptors.request.use(
  pipeGate.createPaymentChannelRequestInterceptor(channelId).request
);

// Add response interceptor for state management
api.interceptors.response.use(
  pipeGate.createPaymentChannelResponseInterceptor().response
);

// Make API calls as normal
const response = await api.get("/endpoint");

Monitoring Channel State

// Get current channel state
const channelState = pipeGate.getChannelState(channelId);
console.log("Current Balance:", channelState?.balance);
console.log("Channel Status:", channelState?.status);

Adding a new Channel

// Get current channel state
await pipeGate.addNewChannel(channel.channelId, channel);

Making API Calls with One time Payment method

Using with Axios

Create an Axios instance with PipeGate interceptors and the txHash of the transaction that was used to pay for the request:

import axios from "axios";

const api = axios.create({
  baseURL: "https://api.example.com",
});

// Add request interceptor for automatic signing
api.interceptors.request.use(
  pipeGate.createOneTimePaymentRequestInterceptor(txHash).request
);

// Make API calls as normal
const response = await api.get("/endpoint");

Advanced Usage

Manual Request Signing

If you need to sign requests manually:

const channelState = pipeGate.getChannelState(channelId);
if (!channelState) throw new Error("Channel not found");

const requestBody = { foo: "bar" };
const signedRequest = await pipeGate.signRequest(channelState, requestBody);

// Use the signed request in your API call
const response = await fetch("https://api.example.com/endpoint", {
  method: "POST",
  headers: {
    "x-Message": signedRequest.message,
    "x-Signature": signedRequest.signature,
    "x-Timestamp": signedRequest.timestamp,
    "x-Payment": JSON.stringify(channelState),
  },
  body: JSON.stringify(requestBody),
});

WASM exported functions - Verifiers & Extra

PaymentChannelVerifier can be used as such:

await init();

const rpc_url = "https://base-sepolia-rpc.publicnode.com";

const verifier = new PaymentChannelVerifier(rpc_url);

const updatedChannel = await verifier.verify_request(
  data.message,
  data.signature,
  data.paymentChannelJSON,
  data.paymentAmount,
  data.bodyBytes
);

console.log(updatedChannel);

Test script can be found in tests/wasm.ts

Best Practices

1. Channel Management

   • Create channels with appropriate duration and funding
   • Monitor channel balance and top up when needed
   • Close channels when they're no longer needed

2. Error Handling

   • Always handle potential errors in channel creation
   • Monitor for signature verification failures
   • Handle channel state updates appropriately

3. Security

   • Never commit private keys or .env files
   • Validate channel states before making requests
   • Keep track of nonces to prevent replay attacks

Types Reference

interface CreateChannelParams {
  recipient: `0x${string}`;
  duration: number;
  tokenAddress: `0x${string}`;
  amount: number;
}

interface CreateChannelResponse {
  channelId: bigint;
  channelAddress: `0x${string}`;
  sender: `0x${string}`;
  recipient: `0x${string}`;
  duration: bigint;
  tokenAddress: `0x${string}`;
  amount: bigint;
  price: bigint;
  timestamp: bigint;
}

interface PaymentChannelResponse {
  address: string;
  sender: string;
  recipient: string;
  balance: string;
  nonce: string;
  expiration: string;
  channel_id: string;
}

interface SignedRequest {
  message: string;
  signature: string;
  timestamp: string;
}

Error Handling

The SDK throws specific errors that should be handled in your application:

try {
  await pipeGate.createPaymentChannel(params);
} catch (error) {
  if (error.message.includes("insufficient funds")) {
    // Handle insufficient funds error
  } else if (error.message.includes("invalid recipient")) {
    // Handle invalid recipient error
  } else {
    // Handle other errors
  }
}

Examples

Complete API Integration Example with recurring Payment Channel method

import { ClientInterceptor } from "pipegate-sdk";
import axios from "axios";

async function setupApiClient() {
  // Initialize SDK
  const pipeGate = new ClientInterceptor();
  await pipeGate.initialize();

  // Create payment channel
  const channel = await pipeGate.createPaymentChannel({
    recipient: "0x123...",
    duration: 30 * 24 * 60 * 60, // 30 days
    tokenAddress: "0x456...",
    amount: "100",
  });

  await pipeGate.addNewChannel(channel.channelId, channel);

  // Setup API client
  const api = axios.create({
    baseURL: "https://api.example.com",
  });

  // Add interceptors
  api.interceptors.request.use(
    pipeGate.createRequestInterceptor(channel.channelId).request
  );
  api.interceptors.response.use(pipeGate.createResponseInterceptor().response);

  return api;
}

// Usage
const api = await setupApiClient();
const data = await api.get("/endpoint");

Complete API Integration Example with One time Payment method

import { ClientInterceptor } from "pipegate-sdk";
import axios from "axios";

async function setupApiClient() {
  // Initialize SDK
  const pipeGate = new ClientInterceptor();
  await pipeGate.initialize();

  // Define the txHash
  const txHash = "0x123...";

  // Setup API client
  const api = axios.create({
    baseURL: "https://api.example.com",
  });

  // Add interceptors
  api.interceptors.request.use(
    pipeGate.createOneTimePaymentRequestInterceptor(txHash).request
  );

  return api;
}

// Usage
const api = await setupApiClient();
const data = await api.get("/endpoint");

Note: This SDK is designed to work with the PipeGate protocol. Ensure you're using the latest version of the SDK and smart contracts for compatibility.