Spring Boot + Swagger: A Complete Guide to API Documentation
By Ayush Shrivastava. Updated Mon Jun 30 2025When building software, especially APIs (Application Programming Interfaces), clear and accurate documentation is essential. It helps other developers understand how to interact with your service: which routes are available, what data to send, and what kind of response to expect. One of the most widely used tools for API documentation is Swagger.
As backend developers, we're deeply familiar with how APIs work. We know which requests are accepted, what responses are returned, what headers are required, which HTTP methods are used (like GET
to retrieve data, POST
to create, PUT
to update, or DELETE
to remove resources), and what various status codes mean (200 OK
, 404 Not Found
, 500 Internal Server Error
, etc.).
But the people using our APIs, such as frontend developers, QA testers, or third-party clients, don’t always have access to that same level of understanding. Unless we clearly document our API, they’re left guessing or constantly asking for clarification. Good documentation saves time, reduces miscommunication, and makes collaboration smoother.

This is where Swagger comes in. It automatically generates interactive, user-friendly documentation based on the annotations in your code. With Swagger, users can: