Flowwithlit Developer Documentation

Flowwithlit lets you accept payments on your website with an embeddable checkout, verify transactions server-side, and receive webhooks — all authenticated with a simple public/secret API key pair.

Base URL

All API requests are made to the base URL below. Always use HTTPS in production.

https://api.flowwithlit.com

Environments

Flowwithlit has two separate environments. You get a distinct set of API keys for each. Test mode is completely isolated — no real money moves, but the API behaves identically.

Your API Keys

Find your API keys in the Developer API section of your dashboard. You get two keys:

• Public key — safe to include in frontend HTML and JavaScript. Used to identify your merchant account when initiating a checkout session.
• Secret key — never expose this in the browser or in client-side code. Used only on your server to verify transactions and access protected endpoints.

Authentication

Authenticated API endpoints expect your secret key as a Bearer token in the Authorization header:

Authorization: Bearer flw_sec_test_YOUR_SECRET_KEY

The checkout public key is passed as a JSON field in the request body — not in headers.

Request & Response Format

All requests and responses use JSON. Always set:

Content-Type: application/json

Every response has the same envelope:

{
  "success": true,
  "message": "Operation successful",
  "data": { ... }
}

On error, success is false and message describes what went wrong.

What's Next?