typicode/json-server

JSON Server solves a very specific pain point for frontend developers: when you are building a web application, you typically need a backend API to store and retrieve data. But setting up a real backend, a database, a server, authentication, routes, takes significant time and technical knowledge. JSON Server lets you skip all of that by creating a fully working fake API from a simple JSON file in seconds, with no coding required. Here is how it works: you create a plain text file called db.json that describes your data in a structured format called JSON (JavaScript Object Notation, essentially just labeled lists and values). You point JSON Server at that file, and it instantly becomes a working web server. It exposes standard REST API endpoints, meaning it understands all the conventional operations: reading a list of items, fetching a single item by its identifier, creating new items, updating existing ones, and deleting them. It also supports filtering, sorting, pagination, and embedding related records, the kinds of queries a real production API would handle. You would use JSON Server during the early stages of building a web app when the real backend does not exist yet, or when writing automated tests that should not hit a live server, or when building a prototype or demo that needs realistic API behavior without the infrastructure overhead. It is particularly popular for frontend developers learning React, Vue, or similar frameworks who want realistic data without needing backend skills. The tool is written in JavaScript and runs on Node.js, which is a runtime that lets JavaScript code run outside of a browser. You install it via npm (the Node.js package manager) and launch it from the command line.