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Application programming interface (API)

Uygulama Programlama Arayüzü (API)

D3

An API is a defined interface through which one software component requests a capability or data from another component.

Review status: 2026-12-04

Technical explanation

In an AI application, an API can expose a model, retrieval service, database, or business function through specified requests and responses.

Conceptual boundaries

An API is an interface contract, not the underlying model, service, or a guarantee that a request is authorized or correct.

Provider-neutral example

A support application sends an authenticated account-status request to a documented service API and receives the specified response fields.

Limitations

Interface conformance does not prove the truth, completeness, security, or fitness of returned data; applications still need authorization, validation, and error handling.

Related concepts

Atomic claims and evidence

  1. 1.1NIST CSRC Glossary, Application Programming Interface (API)
    Source
    NIST CSRC Glossary, Application Programming Interface (API)
    Source role
    Authoritative source
    Exact locator
    Definition: system access point or library function
    Supported claim
    NIST defines an API as a system access point or library function with well-defined syntax that provides well-defined functionality.
    Last verification
    Review due
    Scope limitation
    This general definition does not specify a network protocol, authorization model, or AI use case.
  2. 2.1Anthropic API, Tool use with Claude
    Source
    Anthropic API, Tool use with Claude
    Source role
    Authoritative source
    Exact locator
    Tool use overview: tool use/function calling and structured call execution
    Supported claim
    Anthropic documents tool use as calling defined or provider-supplied functions and returning a structured call for execution.
    Last verification
    Review due
    Scope limitation
    This describes Anthropic's tool-use interface and does not establish interchangeability across providers.