Open API Spec

Lesson in the Backend Developer Roadmap · Stage 7: Learn about APIs

Last updated 14 September 2026

What is Open API Spec?

OpenAPI Specification (OAS), formerly Swagger, is a standard for defining and documenting RESTful APIs in YAML/JSON format. Describes endpoints, formats, authentication, and metadata. Enables client generation, automated documentation, testing, and promotes API design consistency.

Study this in the interactive course See the whole Backend roadmap

Free resources to learn Open API Spec

Official docsOpenAPI Specification Website
Official docsOpen API Live Editor
VideoOpenAPI 3.0: How to Design and Document APIs with the Latest OpenAPI Specification 3.0
VideoREST API and OpenAPI: It’s Not an Either/Or Question

Open API Spec: common questions

Can I learn Open API Spec in Hindi?

This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain Open API Spec in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.

Is this Open API Spec tutorial for beginners?

It is lesson 40 of 155 in the free Backend roadmap, in stage 7, Learn about APIs. If you are new to Backend, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.