SDKs

Official server-side SDKs for PHP and Node.js. Both wrap the Payments API and include webhook signature verification. API keys are secret — never use them in browser code.

PHP — fastaar/fastaar-php

composer require fastaar/fastaar-php

use Fastaar\FastaarClient;
use Fastaar\WebhookSignature;

$fastaar = new FastaarClient(getenv('FASTAAR_API_KEY'), 'https://fastaar.com');

// Create, retrieve, look up, list
$payment = $fastaar->createPayment([
    'amount' => 500,
    'invoice_id' => 'ORDER-42',
    'success_url' => 'https://shop.example.com/thanks',
]);
$payment = $fastaar->getPayment($payment['id']);
$payment = $fastaar->findByInvoiceId('ORDER-42');
$payments = $fastaar->listPayments(['status' => 'completed']);

// Verify a webhook
$valid = WebhookSignature::verify($secret, $rawBody, $signatureHeader);

Errors throw Fastaar\FastaarException with ->errorType and ->statusCode. Requires PHP 8.1+ with ext-curl.

Node.js — @fastaar/sdk

npm install @fastaar/sdk

import { FastaarClient, verifyWebhookSignature, FastaarError } from '@fastaar/sdk';

const fastaar = new FastaarClient(process.env.FASTAAR_API_KEY, { baseUrl: 'https://fastaar.com' });

const payment = await fastaar.createPayment({ amount: 500, invoice_id: 'ORDER-42', success_url: 'https://shop.example.com/thanks' });
await fastaar.getPayment(payment.id);
await fastaar.findByInvoiceId('ORDER-42');
await fastaar.listPayments({ status: 'completed' });

// Verify a webhook (pass the RAW request body)
const valid = verifyWebhookSignature(secret, rawBody, signatureHeader);

Ships as an ES module (import); zero dependencies; requires Node 18+ (global fetch). Errors throw FastaarError with errorType and statusCode.

Other languages

The API is plain HTTPS + JSON — see the integration guide for raw cURL, and the webhooks page for the signature scheme (HMAC-SHA256 over "{t}.{raw_body}"). WordPress and WHMCS plugins are on the roadmap.