Open source. Open possibilities.

JSON Server is a Node.js CLI tool that turns a JSON or JSON5 file into a full fake REST API in seconds, supporting CRUD, filtering, sorting, pagination, embedding, and static file serving for prototyping and testing.

Bogus is a simple, popular fake data generator for .NET (C#, F#, VB.NET). It generates realistic test data like names, addresses, and emails using fluent syntax or direct access. Supports numerous locales for internationalization.

Faker is a Python package used to generate synthetic data for database bootstrapping, stress testing, and data anonymization.