# JSON Server — Full Fake REST API with Zero Coding

> A Node.js tool that turns a JSON file into a fully functional REST API in seconds. Useful for frontend prototyping, mocking backends during development, and creating demo APIs without writing any server code.

## Install

Save in your project root:

# JSON Server — Full Fake REST API with Zero Coding

## Quick Use
```bash
npm install -g json-server
echo '{"posts":[{"id":1,"title":"Hello"}]}' > db.json
json-server --watch db.json
```

## Introduction
JSON Server provides a full fake REST API from a single JSON file. It was created to let frontend developers prototype and develop against a realistic API without waiting for backend teams. Point it at a `db.json` file and you get GET, POST, PUT, PATCH, and DELETE routes with pagination, filtering, sorting, and full-text search.

## What JSON Server Does
- Creates RESTful CRUD endpoints from any JSON file automatically
- Supports filtering, pagination, sorting, and full-text search via query parameters
- Watches the JSON file for changes and reflects them in real time
- Serves static files from a `public` directory alongside the API
- Supports custom routes, middleware, and programmatic usage as a Node.js module

## Architecture Overview
JSON Server is built on Express.js. It reads a JSON file as an in-memory lowdb database, generates RESTful routes for each top-level key, and writes changes back to the file. Custom middleware can be added to intercept requests, and a `routes.json` file enables URL rewriting to simulate complex API structures.

## Self-Hosting & Configuration
- Install globally with npm or use npx for one-off usage without installation
- The `--port` flag changes the default port from 3000
- Add a `routes.json` file for custom URL mappings like `/api/v1/posts` to `/posts`
- Use `--middlewares` to inject custom Express middleware for auth simulation or logging
- Mount JSON Server as middleware inside an existing Express app for hybrid setups

## Key Features
- Instant REST API from a flat JSON file with zero boilerplate
- Full CRUD operations with automatic ID generation for new records
- Query parameter support for `_page`, `_limit`, `_sort`, `_order`, and `q` (search)
- Relationships via `_expand` and `_embed` for nested resource responses
- Snapshot feature saves the current database state on demand

## Comparison with Similar Tools
- **MSW (Mock Service Worker)** — intercepts requests at the network level in the browser; JSON Server runs as a real HTTP server
- **Mirage.js** — in-memory mock server that runs in the browser; JSON Server provides a standalone process accessible from any client
- **WireMock** — Java-based HTTP mock with request matching; heavier setup than JSON Server's single-file approach
- **Mockoon** — desktop GUI for designing mock APIs; JSON Server is CLI-first and scriptable

## FAQ
**Q: Does JSON Server persist data?**
A: Yes, changes are written back to the JSON file on disk. Restarting the server reloads from the file.

**Q: Can I use it in production?**
A: JSON Server is designed for development and prototyping. It uses a flat file as storage and lacks authentication, rate limiting, and other production requirements.

**Q: How do I add authentication?**
A: Add custom Express middleware via the `--middlewares` flag or mount JSON Server inside a larger Express app that handles auth.

**Q: Does it support nested resources?**
A: Use `_embed` to include child resources and `_expand` to include parent resources in responses.

## Sources
- https://github.com/typicode/json-server
- https://github.com/typicode/json-server#getting-started

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Source: https://tokrepo.com/en/workflows/asset-b92132b4
Author: AI Open Source