API v3.2 — Now with Arc L2 support

Build the Future of Payments

Comprehensive APIs and SDKs to integrate global payment infrastructure into any application. Accept on-chain stablecoin payments, manage subscriptions, and build marketplace experiences — all on the Arc blockchain.

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bash

$ npm install @insfers/sdk
$ curl https://api.insfers.com/v3/payments \
    -H "Authorization: Bearer sk_test_..." \
    -d amount=1000 -d currency=usdc -d chain=arc

Accept Your First Payment in 10 Minutes

From zero to processing payments in five straightforward steps.

Create Your Account

Install the SDK

Add the Insfers SDK to your project using your preferred package manager.

Create a Payment

Use the Payments API to create a charge. Specify the amount in the smallest currency unit (cents).

Handle Webhooks

Set up a webhook endpoint to receive real-time notifications when payments succeed or fail.

Go Live

Switch from test keys to live keys in your dashboard. No code changes required.

bash

npm install @insfers/sdk

javascript

import Insfers from '@insfers/sdk';

const insfers = new Insfers('sk_test_your_key_here');

// Create a payment
const payment = await insfers.payments.create({
  amount: 2500,       // $25.00 in USDC
  currency: 'usdc',
  chain: 'arc',
  description: 'Order #1234',
  metadata: {
    order_id: '1234',
    customer_email: 'customer@example.com',
  },
});

console.log(payment.id);       // pay_abc123
console.log(payment.status);   // "pending"
console.log(payment.checkout_url); // redirect customer here

API Reference

RESTful APIs with predictable resource-oriented URLs, JSON request and response bodies, and standard HTTP methods.

Payments

Stable

Create, confirm, capture, and retrieve payments. Supports one-time and recurring charges with full lifecycle management.

12 endpointsView Reference

Refunds

Stable

Issue full or partial refunds on completed payments. Track refund status and receive webhook notifications.

5 endpointsView Reference

Customers

Stable

Store customer profiles, payment methods, and transaction history. Link customers to subscriptions and invoices.

8 endpointsView Reference

Payment Intents

Stable

Build advanced checkout flows with multi-step confirmation. Handle 3DS authentication and wallet selection.

6 endpointsView Reference

Invoices

Stable

Generate and send professional invoices. Auto-collect payments and track outstanding balances.

9 endpointsView Reference

Subscriptions

Manage recurring billing with plans, trials, proration, and usage-based pricing. Automatic retries on failed payments.

11 endpointsView Reference

Connect

Power marketplace and platform payments. Onboard connected accounts, split payments, and manage payouts.

14 endpointsView Reference

All endpoints support pagination, filtering, and expanding nested objects.

Explore Full API Docs

SDKs & Libraries

Official client libraries in 7 languages. Fully typed, well-documented, and open source.

JavaScript / Node.js

npm install @insfers/sdk

Docs GitHub

Python

pip install insfers

Docs GitHub

Ruby

gem install insfers

Docs GitHub

PHP

composer require insfers/insfers-php

Docs GitHub

Go

go get github.com/insfers/insfers-go

Docs GitHub

Java

implementation 'com.insfers:insfers-java:3.x'

Docs GitHub

.NET

dotnet add package Insfers.Net

Docs GitHub

Missing your language? Request it on GitHub or use our REST API directly.

Webhooks

Receive real-time notifications for every event in your payment lifecycle. Signed, retried, and delivered in order.

Available Events

payment.created

payment.completed

payment.failed

payment.expired

refund.created

refund.completed

customer.created

customer.updated

subscription.created

subscription.renewed

subscription.canceled

invoice.paid

invoice.overdue

payout.completed

connect.account.updated

Cryptographic signature verification on every payload

Automatic retries with exponential backoff for up to 72 hours

Event logs with payload inspection in your dashboard

javascript

import Insfers from '@insfers/sdk';
import express from 'express';

const app = express();
const insfers = new Insfers('sk_test_your_key_here');

app.post('/webhooks/insfers', express.raw({ type: 'application/json' }), (req, res) => {
  const signature = req.headers['insfers-signature'];

  let event;
  try {
    event = insfers.webhooks.verify(req.body, signature, 'whsec_your_secret');
  } catch (err) {
    console.error('Webhook signature verification failed:', err.message);
    return res.status(400).send('Invalid signature');
  }

  switch (event.type) {
    case 'payment.completed':
      const payment = event.data;
      console.log('Payment succeeded:', payment.id);
      // Fulfill the order
      break;

    case 'payment.failed':
      console.log('Payment failed:', event.data.id);
      // Notify the customer
      break;

    case 'refund.created':
      console.log('Refund initiated:', event.data.id);
      break;

    default:
      console.log('Unhandled event type:', event.type);
  }

  res.json({ received: true });
});

app.listen(3000);

Test Mode Sandbox

Build and test with confidence using our full-featured sandbox environment. No real money, no risk.

Test API Keys

All keys prefixed with sk_test_ operate in sandbox mode. Switch to sk_live_ when you are ready to go to production.

Simulated Payments

Use test wallet addresses to simulate successful payments, declines, and edge cases without spending real USDC.

Clock Controls

Fast-forward time to test subscription renewals, invoice due dates, and trial expirations.

Webhook Testing

Trigger test webhook events from the dashboard or CLI. Inspect payloads and debug delivery issues.

Error Simulation

Force specific error codes and network conditions to verify your error handling and retry logic.

Idempotency

Test idempotent requests safely. Replay operations to verify your integration handles duplicates correctly.

Test Scenarios

Wallet Address	Behavior	Use Case
`0xTEST_SUCCESS_0001`	Payment succeeds	Happy path testing
`0xTEST_DECLINE_0002`	Payment declined	Decline handling
`0xTEST_PENDING_0003`	Payment stays pending	Async flow testing
`0xTEST_TIMEOUT_0004`	Network timeout	Retry logic validation
`0xTEST_PARTIAL_0005`	Partial payment	Underpayment handling

Code Examples

Copy-paste examples for the most common integration patterns.

Hosted Checkout

Redirect customers to a secure, Insfers-hosted payment page. No frontend code needed — we handle the entire checkout UI, wallet connection, and confirmation flow.

PCI compliance handled for you
Mobile-optimized UI
Supports multiple wallets
Custom branding options

javascript

// Create a hosted checkout session
const session = await insfers.checkout.sessions.create({
  line_items: [
    {
      name: 'Pro Plan',
      amount: 4900,
      quantity: 1,
    },
  ],
  success_url: 'https://yoursite.com/success?session_id={SESSION_ID}',
  cancel_url: 'https://yoursite.com/cancel',
});

// Redirect the customer
res.redirect(303, session.url);

Recurring Subscriptions

Build subscription billing with automatic renewals, proration, trials, and smart retries for failed payments. Supports both fixed-price and usage-based models.

Free trial support
Proration on plan changes
Usage-based billing
Dunning and smart retries

javascript

// Create a customer
const customer = await insfers.customers.create({
  email: 'customer@example.com',
  name: 'Jane Doe',
});

// Create a subscription
const subscription = await insfers.subscriptions.create({
  customer: customer.id,
  plan: 'plan_pro_monthly',
  payment_method: 'pm_card_visa',
});

console.log(subscription.status); // "active"
console.log(subscription.current_period_end);

Refunds

Issue full or partial refunds programmatically. Refunds settle on-chain and are tracked in your dashboard with complete audit trails.

Full or partial amounts
Reason tracking
Webhook notifications
On-chain settlement

javascript

// Full refund
const refund = await insfers.refunds.create({
  payment: 'pay_abc123',
});

// Partial refund
const partialRefund = await insfers.refunds.create({
  payment: 'pay_abc123',
  amount: 500, // Refund $5.00 of the original amount
  reason: 'customer_request',
});

console.log(refund.status); // "succeeded"

Marketplace Payments (Connect)

Power multi-party payments for platforms and marketplaces. Onboard sellers, split payments, and handle payouts automatically with Insfers Connect.

Connected account onboarding
Flexible split payments
Automatic payouts
Platform fee collection

javascript

// Create a connected account
const account = await insfers.connect.accounts.create({
  type: 'standard',
  email: 'seller@marketplace.com',
  capabilities: {
    payments: { requested: true },
    payouts: { requested: true },
  },
});

// Create a split payment
const payment = await insfers.payments.create({
  amount: 10000,
  currency: 'usdc',
  chain: 'arc',
  transfer_data: {
    destination: account.id,
    amount: 8500, // Seller receives $85.00, platform keeps $15.00
  },
});

Join the Developer Community

Connect with thousands of developers building on Insfers. Get help, share ideas, and contribute to the ecosystem.

Discord

Chat with the team and other developers in real time. Get help within minutes.

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GitHub

Explore our open-source SDKs, report issues, and contribute to the codebase.

View GitHub

Stack Overflow

Browse answered questions or ask your own with the insfers tag.

Browse Q&A

Blog

Technical deep dives, integration guides, and product updates from the engineering team.

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Developer Support

Every plan includes documentation access and community support. Upgrade for faster response times and dedicated assistance.

Documentation

Comprehensive guides, API reference, tutorials, and code examples.

Full API reference
Integration guides
Migration playbooks
Code examples in 7 languages

Community

Get help from other developers and Insfers engineers on Discord and Stack Overflow.

Discord community access
Stack Overflow support
GitHub issue tracking
Community office hours

Join Community

Email Support

Direct support from the Insfers engineering team via email with 24-hour response times.

24-hour response time
Technical troubleshooting
Integration review
Available on all paid plans

Contact Support

Priority Support

Fast-track support for production issues with guaranteed response times.

4-hour response SLA
Dedicated Slack channel
Priority bug fixes
Available on Growth plan

Upgrade Plan

Enterprise

White-glove support with a dedicated solutions engineer and custom SLAs.

1-hour response SLA
Dedicated solutions engineer
Architecture review
Custom integration support

Talk to Sales

Start Building Today

Get your API keys in seconds. No credit card required. Full sandbox access with test mode so you can build and iterate before going live.

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Free to startNo credit cardFull sandbox access99.99% uptime SLA

Build the Future of Payments

bash

$ npm install @insfers/sdk
$ curl https://api.insfers.com/v3/payments \
    -H "Authorization: Bearer sk_test_..." \
    -d amount=1000 -d currency=usdc -d chain=arc

import Insfers from '@insfers/sdk'; const insfers = new Insfers('sk_test_your_key_here'); // Create a payment const payment = await insfers.payments.create({ amount: 2500, // $25.00 in USDC currency: 'usdc', chain: 'arc', description: 'Order #1234', metadata: { order_id: '1234', customer_email: 'customer@example.com', }, }); console.log(payment.id); // pay_abc123 console.log(payment.status); // "pending" console.log(payment.checkout_url); // redirect customer here

import Insfers from '@insfers/sdk'; import express from 'express'; const app = express(); const insfers = new Insfers('sk_test_your_key_here'); app.post('/webhooks/insfers', express.raw({ type: 'application/json' }), (req, res) => { const signature = req.headers['insfers-signature']; let event; try { event = insfers.webhooks.verify(req.body, signature, 'whsec_your_secret'); } catch (err) { console.error('Webhook signature verification failed:', err.message); return res.status(400).send('Invalid signature'); } switch (event.type) { case 'payment.completed': const payment = event.data; console.log('Payment succeeded:', payment.id); // Fulfill the order break; case 'payment.failed': console.log('Payment failed:', event.data.id); // Notify the customer break; case 'refund.created': console.log('Refund initiated:', event.data.id); break; default: console.log('Unhandled event type:', event.type); } res.json({ received: true }); }); app.listen(3000);

Wallet Address

Behavior

Use Case

0xTEST_SUCCESS_0001

Payment succeeds

Happy path testing

0xTEST_DECLINE_0002

Payment declined

Decline handling

0xTEST_PENDING_0003

Payment stays pending

Async flow testing

0xTEST_TIMEOUT_0004

Network timeout

Retry logic validation

0xTEST_PARTIAL_0005

Partial payment

Underpayment handling

// Create a hosted checkout session const session = await insfers.checkout.sessions.create({ line_items: [ { name: 'Pro Plan', amount: 4900, quantity: 1, }, ], success_url: 'https://yoursite.com/success?session_id={SESSION_ID}', cancel_url: 'https://yoursite.com/cancel', }); // Redirect the customer res.redirect(303, session.url);

// Create a customer const customer = await insfers.customers.create({ email: 'customer@example.com', name: 'Jane Doe', }); // Create a subscription const subscription = await insfers.subscriptions.create({ customer: customer.id, plan: 'plan_pro_monthly', payment_method: 'pm_card_visa', }); console.log(subscription.status); // "active" console.log(subscription.current_period_end);

// Full refund const refund = await insfers.refunds.create({ payment: 'pay_abc123', }); // Partial refund const partialRefund = await insfers.refunds.create({ payment: 'pay_abc123', amount: 500, // Refund $5.00 of the original amount reason: 'customer_request', }); console.log(refund.status); // "succeeded"

// Create a connected account const account = await insfers.connect.accounts.create({ type: 'standard', email: 'seller@marketplace.com', capabilities: { payments: { requested: true }, payouts: { requested: true }, }, }); // Create a split payment const payment = await insfers.payments.create({ amount: 10000, currency: 'usdc', chain: 'arc', transfer_data: { destination: account.id, amount: 8500, // Seller receives $85.00, platform keeps $15.00 }, });