I need an integration that continuously pulls fleet availability from Vik Rent Car, sends confirmed reservations to Caren through the Caren API, and rejects any request that would create an overlap. Real-time availability checks are mandatory, so the moment a slot is taken in either system the other reflects it instantly. The core workflow is: 1. Authenticate securely to both platforms (token management, encrypted secrets, no hard-coded keys). 2. Call Vik Rent Car endpoints on a schedule short enough to feel instantaneous, parse the response, and update an internal cache. 3. When a booking is created or modified, push the data to Caren via its API, confirm success, then write back any response codes or references. 4. If the slot is no longer available during the final commit step, abort gracefully and notify with a clear error message. 5. Optionally, extend the same channel to sync prices once the availability flow is stable—keep this in mind when structuring the code. Acceptance criteria • Zero double bookings under stress tests. • All authentication secrets stored outside source control. • Clear log entries for every API call and handled exception. • README explaining setup, environment variables, and how to toggle the price-sync module. Deliverables • Well-commented source code (language of your choice, REST-friendly). • Postman or cURL collection that demonstrates every endpoint used. • Brief deployment guide and rollback steps.