A defined contract that lets one program call another over the network.
1 min readupdated 2026-06-22
/ quick answer
An API (Application Programming Interface) exposes functionality as callable endpoints. Modern APIs are usually REST or GraphQL over HTTPS, authenticated with keys or OAuth. Every automation stack is API glue. A defined contract that lets one program call another over the network.
A defined contract that lets one program call another over the network. An API (Application Programming Interface) exposes functionality as callable endpoints. Modern APIs are usually REST or GraphQL over HTTPS, authenticated with keys or OAuth. Every automation stack is API glue. In practice: OpenAI's /v1/chat/completions is the API most AI apps are built on. You POST messages, you get tokens back. This dictionary node is part of the Onexial knowledge graph and links to related concepts, workflows and tools below.
Definition
An API (Application Programming Interface) exposes functionality as callable endpoints. Modern APIs are usually REST or GraphQL over HTTPS, authenticated with keys or OAuth. Every automation stack is API glue.
Example
OpenAI's /v1/chat/completions is the API most AI apps are built on. You POST messages, you get tokens back.
/ frequently asked
What is API?
An API (Application Programming Interface) exposes functionality as callable endpoints. Modern APIs are usually REST or GraphQL over HTTPS, authenticated with keys or OAuth. Every automation stack is API glue.
What is an example of API?
OpenAI's /v1/chat/completions is the API most AI apps are built on. You POST messages, you get tokens back.
Why does API matter for AI and automation?
A defined contract that lets one program call another over the network. It connects to the workflows, prompts and tool stacks linked on this page, so you can move from definition to execution without leaving Onexial.