Smart Rail Routing
One API call, automatic routing to the optimal payment rail based on speed, cost, and availability. You send the payment — we pick the fastest path.
POST /v1/paymentsEverything Payments
Accept, send, vault, and monitor — all through a single, composable API.
Real-Time Event Streaming
Every state change fires a webhook with automatic retries, HMAC signature verification, and an event dashboard for debugging.
- At-least-once delivery guarantee
- HMAC-SHA256 signature verification
- Automatic exponential backoff retries
- Full event log with replay capability
SDKs for Every Stack
First-class SDKs in 6 languages, auto-generated from our OpenAPI 3.1 spec and hand-tuned for idiomatic usage.
import { Kinetic } from '@kinetic/flow';
const kinetic = new Kinetic('sk_live_...');
const payment = await kinetic.payments.create({
amount: 50000,
currency: 'USD',
rail: 'ach',
destination: 'acc_28471',
idempotencyKey: 'pay_unique_123',
});
console.log(payment.id); // "pay_8842"Live in 4 Steps
From signup to production in the same afternoon.
Get API Keys
Sign up and receive sandbox keys in seconds. No sales call required.
Install SDK
npm, pip, gem — pick your language and install Flow's SDK in one command.
Send First Payment
Create a payment with a single API call. See it complete in real-time.
Go Live
Swap sandbox keys for production. Same API, same code, real money.