What kind of API does Dynamics 365 have?

Dynamics 365 has a fully featured API. It is not a limited data extract, but the same interface used by the application itself.

Dataverse Web API

A REST API based on OData. It enables reading, writing, updating, and deleting all tables, including custom tables, and also supports running business logic.

Security still applies

This is the most important thing to understand: the API respects security roles. An integration running as a specific user can only see what that user can see. This is an advantage, but it is also the cause of many “why can’t the integration find the data?” cases.

Authentication

Through Microsoft Entra ID. Integrations generally use an application user rather than a personal account—it does not leave the organization, and it has only the permissions you grant it.

Limits

There are limits on the number of calls per unit of time. For large volumes of data, dedicated bulk operation mechanisms are available and should be used instead of thousands of individual calls.