loopback

LoopBack is an open-source Node.js framework for building REST APIs. A REST API is a way for software applications to talk to each other over the web, and building one usually involves a lot of repetitive setup. LoopBack was designed to reduce that work by generating much of it automatically.

With LoopBack 3, you describe your data models (for example, a User, a Product, or an Order) and the framework generates a full set of API endpoints for creating, reading, updating, and deleting those records. It can connect to many different databases and services, including MySQL, PostgreSQL, MongoDB, Oracle, Microsoft SQL Server, and external REST or SOAP services. You can then add rules to control who is allowed to read or modify which data.

The framework also includes optional components for push notifications, file storage, and user authentication via third-party services like Google or Facebook. It came with client libraries for iOS, Android, and browser JavaScript applications, making it possible to build a mobile or web frontend that talks directly to your LoopBack backend.

However, this repository covers LoopBack 3, which reached end of life in December 2020 and is no longer maintained. The README prominently warns that no new pull requests or community support are accepted. Anyone starting a new project should use LoopBack 4, which is a separate repository and a significant rewrite with a different architecture. A migration guide is available for those moving from version 3 to version 4.

If you come across this repo while researching API frameworks, the code here is historical. The concepts it introduced (model-driven API generation, database connectors, access control) carried forward into LoopBack 4, but the two versions are not directly compatible.