Guides

Business Central API guides

Updated 2 November 2026

Practical answers to the questions that come up when you work with the Business Central API, based on Microsoft's documentation.

• How to connect to the Business Central API with OAuth 2.0Register the app, grant permissions, enable it in Business Central and make your first call.
• Business Central API errors explainedWhat AADSTS sign-in codes and Business Central error codes mean, and how to fix each.
• How to create and post a sales order with the Business Central APIThe three calls: create the order, add its lines, then ship and invoice it.
• How to fix If-Match and ETag errors in the Business Central APIWhy updates need an ETag, where to get it, and what the errors mean.
• How to read Business Central $metadata and build JSON request bodiesWhere $metadata lives, how to read it, and how to turn it into a request body.
• A Postman alternative built for Business CentralHow the two compare, and when Postman is still the better choice.