For managing your expenses and invoices, Perk provides a RESTful API based on the OpenAPI Specification (version 3.0). It is designed to import master and configuration data into Perk and export financial data to third-party systems.

You can use the Spend API, for example, to retrieve expenses, trips and invoices, export journal entries, and upload your own foreign exchange rates.

For more information, check out REST API in Perk Developers.