Whiplash API
The Whiplash REST API (now RyderShip API) enables developers to manage orders, items, inventory, shipments, consumer returns, customers, and notification subscriptions programmatically. The API uses OAuth 2.0 Bearer token authentication and supports both authorization code and client credentials flows.
Documentation
Documentation
https://help.whiplash.com/hc/en-us/categories/13378954544411-Whiplash-Application-Developers
Authentication
https://help.whiplash.com/hc/en-us/articles/360050870691-Authentication-for-the-V2-API
RateLimits
https://help.whiplash.com/hc/en-us/articles/38805892080667-API-Rate-Limits-and-Best-Practices