What is the difference between OpenAPI and Swagger?

Swagger was the original name, now owned by SmartBear. OpenAPI is the vendor-neutral specification. OpenAPI 3.0+ is the modern standard. Swagger tools still exist and support OpenAPI.

Should I use OpenAPI 3.0 or 3.1?

OpenAPI 3.1 has better JSON Schema support but less tool support currently. 3.0 is widely supported. Choose based on your tooling needs. Both are good choices.

How do I create an OpenAPI spec?

Options: write YAML/JSON manually, use Swagger Editor, generate from code annotations, use design-first tools (Stoplight, SwaggerHub). Design-first often produces better APIs.

What is contract-first development?

Design the API spec first, then implement. Enables parallel frontend/backend work, better API design, early feedback. OpenAPI enables this pattern effectively.

Book Free Assessment Calculator

OpenAPI Specification

A standard, language-agnostic format for describing REST APIs, enabling documentation, code generation, and testing.

In-Depth Explanation

OpenAPI Specification (formerly Swagger) is a standard format for describing REST APIs. It enables automatic documentation generation, client SDK generation, testing, and API development tooling.

OpenAPI components:

Info: API metadata (title, version)
Servers: API base URLs
Paths: Endpoints and operations
Components: Reusable schemas, parameters
Security: Authentication definitions

Key benefits:

Human and machine readable (YAML/JSON)
Auto-generate documentation (Swagger UI)
Generate client SDKs in many languages
Enable API testing tools
Contract-first development

Version history:

Swagger 2.0 (now OpenAPI 2.0)
OpenAPI 3.0 (major improvements)
OpenAPI 3.1 (JSON Schema alignment)

Common tools:

Swagger UI (interactive docs)
Swagger Editor (spec editing)
OpenAPI Generator (code generation)
Postman (imports OpenAPI)

Business Context

OpenAPI standardises API documentation, making APIs more accessible to developers and enabling powerful tooling.

How Clever Ops Uses This

We document all APIs using OpenAPI for Australian businesses, ensuring clear specifications and enabling automated client generation.

Example Use Case

"Publishing an OpenAPI spec that automatically generates Swagger UI documentation, TypeScript client SDK, and Postman collection for API testing."

Frequently Asked Questions

Related Terms

REST API API Documentation

Learn More

API Integration Patterns: Building Reliable, Scalable LLM Applications

Master patterns for integrating with LLM APIs reliably at scale. Learn error handling, rate limiting, caching, cost optimization, and production-ready architectures for OpenAI, Anthropic, and other providers.

Read article

OpenAI Platform Operational Analytics