Application Programming Interface (API)

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Definition

An API is a defined contract that lets software talk to software. It exposes functions and data through predictable endpoints, methods, and schemas so clients can request or change resources safely and consistently.

Examples

  • A mobile app calls GET /v1/users/me over HTTPS with an OAuth 2.0 access token to fetch the signed-in user’s profile.
  • A payment provider sends a webhook POST /payments/events; the receiving API verifies the signature before updating an order.

Discover 🔎

APIs are the glue of modern systems. Websites, mobile apps, and back-office services all exchange data through an API rather than reaching directly into each other’s databases. The power of an API comes from its contract: what you can ask for, how you ask, and what you’ll get back—every time.

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