Java tools and extensions for pi

This repo contains pi extensions and skills for Java Spring Boot development. It uses pi (pi.dev) which is a a minimal agentic coding tool and terminal coding harness. Why use pi? It is minimal, has a very small footprint and initial context that it sends to an LLM, hence is fast and lightweight.

This project provides a number of tools to build a Java application - and is a mini software factory that will build a complete application from a spec!

This project is currently BETA so use with care! It has a minimal permissions gate (the default one built into pi itself).

AI Models

I've used this to test the capability of local and cloud models including:

• Qwen3.6 27B and 35B-A3 (running local!)
• Gemini 3.1 Flash and Pro
• Sonnet 4.6

Getting started

The extension java-workflow will take a spec.md file and:

analyze → architect → develop → test → review → fix → verify

Here's how to get started and build a full Java application in a few mins

• Go to https://pi.dev/ and install pi using the instructions at the top.
• Select a model to use:
  • You'll get asked on installation to setup an env variable for major providers
  • You can get the config by going to https://pi.dev/models and selecting/searching for provider & model (note that this lists the same model multiple times by provider!)
  • You can also ask pi itself to help configure this! But be warned, it may overwrite your existing ~/.pi/agent/models.json file if you're not careful!
  • use /model within pi select a model
• Let's build an app! Open a new terminal window and run:

mkdir tmp && cd tmp
git clone https://github.com/prpatel/pi-java-tools
mkdir spring-boot-todo && cd spring-boot-todo
pi -e ../pi-java-tools

Then in the pi session, run:

/java-workflow ../pi-java-tools/example-specs/todo.md

The pi agent will now start building out the todo application!

The pi -e flag loads the extension only for this specific run of pi. You can install it as a permanent extension using the instructions below.

Next steps

If you're a java developer, you already know how to start this Spring Boot application, but you can just tell pi to do it! Just type this in and hit enter:

run the application and open a browser so I can test it

You can have a look at the spec file while it's running to see the requirements, structure, standards (like use Java 21 records) etc. Here's the tech stack I put in the spec:

• Backend Framework: Spring Boot 3.x
• Language: Java 21
• Build Tool: Maven
• Database: H2 (In-memory) for simplicity
• Frontend UI: Thymeleaf (Server-Side Rendering)
• Frontend Assets: Standard HTML5, CSS3, Vanilla JavaScript (Fetch API)
• Testing: JUnit 5, MockMvc, Mockito

Depending on the model you used, the application may need some bug fixes. You can tell pi to fix them:

When I click the checkbox nothing happens. Fix it.

Check out the pi docs https://pi.dev/docs/latest, they are quite good... or just ask pi to help you!

If you have questions or suggestions, msg me on LinkedIn: https://www.linkedin.com/in/prpatel/

What's included

Extensions (3)

Extension	Tools
java-spring-tools	spring_initializr, maven_run, java_run, java_stop, java_add_dependency, java_dependency_tree
java-qa-tools	java_test_runner, java_static_analysis, java_test_coverage
java-workflow	Automated lifecycle: analyze → architect → develop → test → review → fix → verify

Skills (8)

Skill	Role
spec-analyst	Breaks down specs into requirements, data models, and API contracts
spring-boot-architect	Scaffolds Spring Boot projects with clean architecture
java-developer	Writes idiomatic Spring Boot code with TDD
java-qa-engineer	Writes JUnit 5 / Mockito / TestContainers tests
java-reviewer	Strict code review: SOLID, security, performance
java-debugging	JVM debugging, thread dumps, heap analysis
maven-workflow	Maven builds, dependency management, plugin config
spring-boot-workflow	Profiles, actuator, testing patterns, deployment

Install

Via git

pi install git:github.com/prpatel/pi-java-tools@v1.0.0

View the release on GitHub.

Try without installing

pi -e /path/to/pi-java-tools

Usage

Once installed, the tools and skills are auto-discovered in every pi session.

Run the automated workflow

/java-workflow "Create a REST API for user management with CRUD operations"

This orchestrates the full lifecycle: spec analysis → scaffolding → implementation → testing → code review → fixes → verification.

Use individual tools

The LLM automatically uses the appropriate tools based on your requests:

• "Scaffold a Spring Boot project" → spring_initializr
• "Run the tests" → java_test_runner
• "Start the app" → java_run
• "Check coverage" → java_test_coverage

Example Specs

The package includes 3 ready-to-use spec files in example-specs/:

Spec	Complexity	What it builds
user-api.md	⭐ Basic	User CRUD API with validation, H2, error handling
todo-api.md	⭐⭐ Intermediate	Todo API with JWT auth, roles, PostgreSQL
todo.md	⭐⭐⭐ Advanced	Full-stack Todo app with Thymeleaf UI + REST API

After installing, run one with:

/java-workflow /path/to/pi-java-tools/example-specs/user-api.md

(See the spec on GitHub.)

License

MIT