Meet J2Bot: Transform Your Models into Full-Stack Apps Instantly

J2Bot is a Codebot, published on the Codebots platform, that turns structured models into working applications. It brings together models, templates, and pipelines to generate compiled code, tests, and documentation. This article introduces J2Bot and demonstrates how it works.

Demo

Check out the introduction to J2Bot, a demo of it in action and a review of a demonstration target app it can control!

With J2Bot, you model your system and generate:

• Backend services and REST APIs in Java/Spring Boot
  
• Frontend components in React/TypeScript
  
• PostgreSQL schema
  
• Automated tests and traceability reports
  

What would take weeks of manual coding is streamlined into hours.

Technology Stack

• Frontend: React + TypeScript
  
• Backend: Java with Spring Boot
  
• Database: PostgreSQL
  
• Testing: Unit X, Playwright, Jest
  

This modern stack allows J2Bot to create full-stack applications that are scalable, testable, and production-ready.

Core Principles

J2Bot follows established architectural principles to ensure quality and consistency:

• Convention over configuration – reduce configuration overhead with sensible defaults.
  
• Models as source of truth – strongly typed, validated, and normalised models.
  
• Separation of concerns – each model focuses on a single domain.
  
• Continuous integration – automated testing and quality gates.
  
• Composable pipelines – modular and reusable for different targets (e.g., microservice vs. full-stack app).
  

How J2Bot Works

J2Bot uses a set of specialised models to generate every layer of an application:

Core: Defines shared base types and superclasses, providing a foundation for consistency.

Requirements: Captures what the system must do, separating functional and non-functional requirements.

Traceability: Links requirements to tests and outputs, ensuring coverage and accountability.

Entity: Defines domain data models. Adding an entity automatically generates:

• Domain objects
  
• Repository classes
  
• Service classes
  
• DTOs (Basic, Read, Write)
  

API: Creates REST endpoints for each entity, supporting standard methods like CREATE, GET, UPDATE, DELETE, SEARCH, plus custom endpoints.

Frontend: Builds pages, layouts, forms, and UI components linked to APIs and entities. Supports actions, state, and security permissions.

Security: Manages roles and access control. Supports both RBAC (Role-Based Access Control) and ABAC (Attribute-Based Access Control), including multi-tenancy.

Generated Outputs

From the models, J2Bot automatically produces:

• Compiled Code – backend logic, APIs, frontend pages, and UI components.
  
• Tests – Playwright, Jest, and unit test templates ensure ongoing quality.
  
• Documentation – requirements, traceability reports, and architecture references.
  

Why J2Bot Matters

• Consistency: Applications share a reliable foundation.
  
• Speed: Reduce repetitive coding with automated generation.
  
• Quality: Built-in tests and validation raise reliability.
  
• Traceability: Clear links from requirements to delivered features.

Conclusion

J2Bot demonstrates the power of model-driven development on the Codebots platform. By combining models, templates, and pipelines, it empowers teams to build, test, and document applications faster and with greater reliability.

J2Bot isn’t just a bot—it’s a system for turning ideas into working software.