Api

In the Compose series, you learned basic Retrofit: define an interface, call an endpoint, show the result. That works for tutorials. In production, you need more. Authentication tokens that refresh automatically. Logging for debugging. Retry logic for flaky networks. Proper error handling that shows meaningful messages. This tutorial builds a production-ready API layer with Retrofit 3, Kotlin Serialization, and OkHttp interceptors. Prerequisites: Compose Tutorial #12: Retrofit basics and Kotlin Tutorial: Serialization. Why Kotlin Serialization Over Gson? Retrofit traditionally used Gson for JSON parsing. Kotlin Serialization is better for modern Android: ...

In the previous article, you built a CLI tool with AI. Now let us scale up. You are going to build a complete REST API — with a database, authentication, tests, and deployment — all driven by AI. The project: a Notes API that lets users create, read, update, and delete notes. It includes user registration, authentication with JWT, PostgreSQL storage, and proper error handling. Simple enough to build in one session, complex enough to show real patterns. ...

Every app needs to talk to the internet. On Android, you use Retrofit. On iOS, you use URLSession. Two different libraries, two different APIs, two different codebases. In KMP, you use Ktor Client — one networking library that works on every platform. Write your API calls once in commonMain, and they work on Android, iOS, Desktop, and Web. What is Ktor? Ktor is a networking framework by JetBrains (the same team behind Kotlin). The client side lets you make HTTP requests from shared code. ...

Every real app needs data from the internet. A weather app calls a weather API. A social app loads posts from a server. A store app fetches products from a backend. Retrofit is the most popular library for making HTTP requests in Android. In this tutorial, you will learn how to use it with Compose to build a screen that loads, displays, and handles errors from a real API. What is Retrofit? Retrofit is an HTTP client library by Square. It turns your API into a Kotlin interface: ...