ToolJet Project Structure
The open-source low-code framework for building business applications. A robust TypeScript application built with NestJS, React, and a modular plugin system.
Updated 2025-12-30
Project Directory
Repository Info
- Repository-ToolJet/ToolJet
- Stars-25k+
- License-AGPL-3.0
- Last Analyzed-December 2025
Tech Stack
- Language-TypeScript
- Backend-Node.js (NestJS)
- Frontend-React
- Database-PostgreSQL
- ORM-TypeORM
- Infrastructure-Terraform / Kubernetes
Architecture Notes
ToolJet follows a classic Enterprise TypeScript architecture. The backend is a structured **NestJS** application using **TypeORM** for robust database interactions. The frontend is a massive React SPA that handles the complex state of the application builder. A key architectural pillar is the plugins/ directory, which provides a standardized way to add third-party integrations (connectors) without modifying the core server code.
Key Directories
- server/src/modules/-Contains the core features of the platform, including workspace management, authentication, and the query execution engine.
- plugins/packages/-Where the 'Connectors' live. Each sub-folder is a separate package for a specific data source (e.g.,
postgresql,googlesheets,restapi). - frontend/src/AppBuilder/-The most complex part of the frontend. It contains the logic for the visual editor, including drag-and-drop, component rendering, and the inspector panel.
Why This Structure?
ToolJet is a great example of a 'Pluggable Monolith'. While the core is a single system, the plugin architecture allows it to scale horizontally in terms of features (integrations) while remaining maintainable.