How APIs work, in words anyone can follow
APIs explained for people who don't code
An API is how one app asks another for something. This site explains requests and replies, keys, limits and error codes in plain words. It also shows why AI tools and business apps depend on them.
All the guides
- What an API is, in plain words
An API is a way for one piece of software to ask another for something. Here's what that means, with plain examples and no code.
- How a request and a response work
What happens when one app asks another for something over the web, covering the request, the reply, the status code and the parts of each message.
- What an API key is and how to keep it secret
An API key is a secret code that identifies your requests. Learn what it does, what a leaked one can cost you, and how makers advise keeping it safe.
- Endpoints and methods: the addresses and verbs of an API
What GET, POST and 'endpoint' mean in API documentation, with plain examples of the address you ask and the action you request.
- JSON for beginners: reading the reply an API sends back
What the block of curly brackets in an API reply is, how names and values pair up, and how to read one without knowing any code.
- Rate limits, quotas and usage charges
Why an API refuses requests that come too fast, how spend limits and quotas work, and where an unexpected bill can come from.
- Reading API error codes like 401, 404 and 429
What the common API error numbers mean, in plain words, and the first thing to check for each one before you ask for help.