What Is a REST API? Architectural Principles and Best Practices
A REST API is an application programming interface that conforms to the architectural constraints of Representational State Transfer (REST), first formalized by Roy Fielding in 2000.
💡 Plain-English Analogy
A REST API organizes data into "nouns" (resources like users, products, or orders) and uses standard HTTP actions ("verbs" like GET, POST, DELETE) to manage them. For example, GET /products retrieves a list, while POST /products creates a new one.
⚙️ Architecture & Under the Hood
True REST relies on six architectural constraints: Client-Server separation, Statelessness, Cacheability, Layered System, Uniform Interface, and optional Code on Demand. REST resources are represented in hypermedia formats (typically JSON) identified by uniform URIs.
Core Principles of RESTful Design
Designing clean REST APIs requires adhering to standard resource naming conventions.
- Use plural nouns for resource endpoints (e.g. /api/articles, not /api/getArticle).
- Rely on HTTP verbs for actions, never verbs in URL paths (POST /api/articles, not /api/createArticle).
- Use nesting for hierarchical relationships (e.g. /api/users/42/orders).
- Statelessness: Every request must contain all information required for the server to process it without relying on server-side session memory.
GET /api/v1/articles -> Retrieve list of all articles
POST /api/v1/articles -> Create a new article
GET /api/v1/articles/105 -> Retrieve article #105
PUT /api/v1/articles/105 -> Overwrite article #105
PATCH /api/v1/articles/105 -> Partially update article #105
DELETE /api/v1/articles/105 -> Remove article #105Frequently Asked Questions
How does REST compare to GraphQL?
REST provides multiple fixed endpoints returning fixed data structures. GraphQL provides a single endpoint where clients request specific fields dynamically, reducing over-fetching at the cost of caching complexity.