REST API
This pattern appears everywhere — recognise it once and you understand most of the internet
What is a REST API
Imagine a restaurant.
You sit down. You look at the menu. You tell the waiter what you want. The waiter goes to the kitchen. The kitchen prepares it. The waiter brings it back.
You do not go into the kitchen. You do not talk to the chef. You use the interface — the menu and the waiter — to get what you need from a system you do not have direct access to.
A REST API works the same way. Your application is the customer. The API is the waiter and menu. The server is the kitchen. You send a request in a standard format — using standard HTTP verbs like GET, POST, DELETE — and you receive a response, typically in JSON.
REST stands for Representational State Transfer. The name is less important than the pattern: a consistent, stateless interface between your application and a remote system.
The number that makes it real
Virtually every AI model API on sourc.dev is a REST API. When you send a prompt to Claude, you make an HTTP POST request to `https://api.anthropic.com/v1/messages` with your prompt in the request body. Anthropic's server processes it and returns JSON with the model's response. That is the entire interaction.
Why this matters to you
Once you understand the REST pattern — you know how to work with almost any modern API. The specific fields change. The endpoints change. The authentication changes. The pattern does not.
If you have called the weather API, you can call the Claude API. If you can call the Claude API, you can call any of the 30 models on sourc.dev. The restaurant changes. The experience of ordering is the same.
Verified March 2026 · Source: Anthropic API documentation