REST (Representational State Transfer) is an architectural style for designing networked applications. A RESTful API uses standard HTTP methods (GET, POST, PUT, DELETE) to perform operations on resources identified by URLs.
REST is built on a few core principles. Resources (like users, posts, or prices) are identified by URLs. Each URL represents a specific thing you can interact with. The HTTP method tells the server what action to take: GET retrieves data, POST creates something new, PUT updates an existing resource, and DELETE removes it.
REST APIs are stateless, meaning each request contains all the information the server needs to process it. The server does not remember previous requests. This makes REST APIs easy to scale because any server in a cluster can handle any request without sharing session data.
Responses are typically formatted in JSON, and the server returns appropriate HTTP status codes (200 for success, 404 for not found, 500 for server error). Well-designed REST APIs are predictable: if you know the pattern, you can often guess what an endpoint does just by reading its URL.
REST is the dominant pattern for web APIs. Nearly every service you interact with online exposes a REST API, from payment processors like Stripe to social platforms like Twitter/X. Understanding REST is foundational for any developer building integrations, consuming third-party data, or designing their own backend services.
The TerminalFeed API follows REST conventions. Every endpoint uses GET requests and returns JSON. For example, GET /api/btc-price returns Bitcoin's current price. Explore all endpoints on the developers page or check our guide on 30+ Free APIs for more RESTful services to experiment with.