Short for application programming interface: a contract that client code calls programmatically, for example a web API secured with tokens or the Files, Images or Responses APIs.
Also called application programming interface.
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Terms in this definition
- Web API
Receives tokens issued by Microsoft Entra, validates them and decides what callers may do based on their
rolesandscpclaims. A web app making the calls acts purely as a client.
Related terms
- Access token
A credential an application hands to an API or other resource to prove what it has been authorised to do for a signed-in user. It deals with permissions, unlike the ID token, which records the sign-in itself.
- Agents (classic) API
First-generation Foundry Agent Service API, based on threads, messages and runs. It is deprecated, replaced by conversations and responses, and retires on 31 March 2027.
- Apache Gremlin
The Apache TinkerPop language for traversing graphs. The matching Azure Cosmos DB API holds data as vertices (the nodes) linked by edges (the relationships), suiting cases where links between items matter, like social networks or recommendation engines.
- API Management
Azure's API gateway, where policies like rate limits, quotas, ip-filter and validate-jwt are defined once and apply to every API. Production VNet injection is offered in the Premium tier.
- API server authorized IP address ranges
AKS capability restricting who can reach the public Kubernetes API server to specified IP ranges. Existing public clusters can have it switched on.
- App roles
Roles declared by an API in its app registration. When one app calls another using client credentials, the assigned roles appear in the token's
rolesclaim. - Application ID URI
Set on the Expose an API page, defaulting to
api://<application-client-id>, this globally unique value names a web API. Prefixing it to a scope name gives the complete scope string. - Assistants API
Azure OpenAI's OpenAI-style API based on assistants, threads and runs. It was deprecated and retired on 26 August 2026, with Foundry agents using conversations and responses taking its place.