Swagger / Readme / Datamodel

3 useful references / libraries are available:

Always Start with documentation on this site
Readme API Endpoints overview: https://docs.billit.be/reference . It contains the parameters and Sample code in nearly 20 development languages.
For a Full list of data elements use, you can looka at Swagger UI Guide https://api.billit.be/swagger/ui/index. For the meaning of earch field, check on this documentation site.

1. What is the Billit API

The Billit API allows you to programmatically interact with Billit’s services — such as invoices, clients, quotes, and payments. It is built around REST endpoints and supports standard CRUD operations (Create, Read, Update, Delete).

2. API Overview and Supported Values

First read documentation on this website.
Then 2 additional sites are available to find detailed list of supported values:
- API Endpoints : https://docs.billit.be/reference/order-1. Including sample code in 20 development languages
- Swagger https://api.billit.be/swagger/ui/index
Browse all available endpoints, methods, parameters, and schemas
Use the interactive interface to test endpoints with “Explore”

3. Common API Endpoints

While the full list is in Swagger, here are examples:

Resource	How can it help you?
Account	Retrieve the context of the Account (aka company) context you are operating in. https://docs.billit.be/docs/create-new-companies
Orders	Perform create, read, update, delete, or query operations on invoices, quotes, and credit notes (both income and expense). Assigning a customer or supplier to an order will either create a new party or link the order to an existing party.
Party	Manage the customers and suppliers of an Account