An application programming interface specifies operations, inputs, outputs, authentication, and error behavior that software can use without depending on another system's internal implementation. Web APIs commonly exchange structured requests and responses over network protocols such as HTTPS.
An API can let an agent retrieve videos, store records, trigger services, or populate an application interface. Integrators need to validate returned data, handle rate limits and failures, protect credentials, and follow the provider's authorization rules.
ELI5
An application programming interface is a defined way for two software systems to request data or actions from each other. It describes available operations, required inputs, returned results, authentication, and how errors are reported.
For example, an AI agent can call a weather API with a location and receive structured forecast data. The application must protect its credentials, validate the response, respect limits, and handle the service being unavailable.
Why do AI agents use application programming interfaces?
APIs give agents controlled access to external data and actions that are not available from the model alone.
Does an application programming interface expose a service's source code?
No. It exposes a defined contract for permitted operations while the service implementation can remain private.
