What makes an API truly RESTful?

A truly RESTful API follows six constraints: client-server separation, statelessness, cacheability, uniform interface, layered system, and (optionally) code on demand. Many APIs labeled "REST" only follow some of these constraints.

How should I version a REST API?

The most common approach is URL versioning (/api/v1/users). Header versioning (Accept: application/vnd.api+json;version=2) is more RESTful but harder to test in a browser. Choose one approach and apply it consistently.

What is the difference between PUT and PATCH?

PUT replaces the entire resource with the request body. PATCH applies a partial update, modifying only the specified fields. Use PATCH for most update operations to avoid accidentally overwriting fields.

REST APIs Explained

The foundational API architecture of the web — resources, HTTP verbs, and stateless communication.

REST API

A REST (Representational State Transfer) API is an architectural style for building web services that uses standard HTTP methods (GET, POST, PUT, DELETE) to perform CRUD operations on resources identified by URLs. It is the most widely adopted API paradigm on the web.

Explanation

REST was introduced by Roy Fielding in 2000 and quickly became the dominant approach for web APIs. Its core principles include: resources are identified by URLs (/users/42), operations map to HTTP verbs (GET to read, POST to create, PUT to update, DELETE to remove), responses are stateless (each request contains all the information needed to process it), and representations are typically JSON or XML. REST APIs are simple to understand, easy to cache (GET requests are naturally cacheable), and supported by every HTTP client and framework. They integrate seamlessly with web infrastructure like CDNs, proxies, and load balancers. The resource-oriented model maps well to database entities, making REST a natural fit for CRUD-heavy applications. However, REST has limitations. Complex data needs may require multiple round trips (fetching a user, then their posts, then comments). Versioning APIs without breaking clients requires careful design (URL versioning, header versioning, or content negotiation). And REST lacks a built-in schema definition, making documentation tools like OpenAPI/Swagger essential for team collaboration.

Bookuvai Implementation

REST is the default API architecture for Bookuvai projects unless the project requirements clearly favor GraphQL. We follow OpenAPI 3.0 specification for all REST APIs, auto-generate TypeScript client SDKs from the spec, and include Swagger UI in every project for interactive API documentation. Our milestone review process includes API contract review to ensure consistency and backward compatibility.

Key Facts

Most widely adopted API architecture, supported by all HTTP clients
Naturally cacheable via HTTP caching headers and CDNs
OpenAPI/Swagger provides standardized documentation and code generation

Related Terms

Frequently Asked Questions

What makes an API truly RESTful?: A truly RESTful API follows six constraints: client-server separation, statelessness, cacheability, uniform interface, layered system, and (optionally) code on demand. Many APIs labeled "REST" only follow some of these constraints.
How should I version a REST API?: The most common approach is URL versioning (/api/v1/users). Header versioning (Accept: application/vnd.api+json;version=2) is more RESTful but harder to test in a browser. Choose one approach and apply it consistently.
What is the difference between PUT and PATCH?: PUT replaces the entire resource with the request body. PATCH applies a partial update, modifying only the specified fields. Use PATCH for most update operations to avoid accidentally overwriting fields.