API key
compound.compound. a secret code that lets one computer program talk to another. You use it like a password to prove who you are when you want to get data from a website or service.
compound. a unique identifier used to authenticate a user, developer, or calling program to an application programming interface. It serves as a security token to track and control how the interface is being used.
You need an API key to use the weather data.
The developer had to generate a new API key after accidentally sharing the old one in a public code repository.
To prevent unauthorized access and manage rate limits, the service provider requires a valid API key for every request sent to their server.
A compound of the initialism API, standing for Application Programming Interface, and the noun key. It follows the established linguistic pattern of using physical security metaphors to describe digital authentication tokens.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Often treated as a single noun phrase; typically requires 'a' or 'the' in singular form.
I put my API key in the public code.I kept my API key in a private file.API keys are sensitive credentials; they should never be hard-coded into public files where others can steal them.
Last updated July 22, 2026