BC API Pages: Standard vs Custom

Business Central has two types of API pages:

• Standard API pages are built and maintained by Microsoft, and they come ready to use out of the box - no development required;
• Custom API pages are AL extensions built by a developer - either by your BC partner or internally. They let you expose exactly the fields you need, including data from extension tables, calculated values,etc.

The Two URL Structures

Standard Microsoft API:

https://api.businesscentral.dynamics.com/v2.0/{tenantId}/{environment}/api/v2.0/companies({companyGuid})/{entitySetName}

Example: https://api.businesscentral.dynamics.com/v2.0/9efb0c96-7560-4413-85b2-e931f9c1fd2d/CRONUS_DEMO/api/v2.0/companies(927fd0e5-c22f-ee11-bdfe-6045bde9b7c2)/customers

Custom API:

https://api.businesscentral.dynamics.com/v2.0/{tenantId}/{environment}/api/{publisher}/{group}/{version}/companies({companyGuid})/{entitySetName}

Example: https://api.businesscentral.dynamics.com/v2.0/9efb0c96-7560-4413-85b2-e931f9c1fd2d/CRONUS_DEMO/api/Rapidi/Integration/v2.0/companies(927fd0e5-c22f-ee11-bdfe-6045bde9b7c2)/customerFinancialSummaries

The difference is those three extra segments in the custom URL: {publisher}, {group}, and {version}. These map directly to properties defined in the AL page object.

Case sensitivity: BC API URLs are case-sensitive, and the entity set name must be lowercase. A single capital letter will return a 404 — worth double-checking before you spend an hour debugging a connection.