Java Dev Assist is an expert AI assistant extension for the Gemini CLI, specializing in Java 17+, Quarkus, and Spring Boot development. It assists developers with code reviews, debugging stack traces, managing dependencies, and enforcing architectural boundaries.

• Stack Specialization: Optimized for Modern Java (17+), Quarkus, and Spring Boot.
• Context Awareness: Automatically detects build systems (Maven/Gradle) and project frameworks to provide relevant suggestions.
• Safety First: Prioritizes non-destructive analysis and asks for confirmation before making changes.
• Architectural Guardrails: Includes specific tools to enforce domain boundaries (e.g., keeping DTOs out of Service layers).

To install this extension from the repository:

gemini extensions install https://github.com/grzegorz-golowicz/java-dev-assist-extension

To install locally for development:

gemini extensions install .

To update the extension after making changes:

gemini extensions uninstall java-dev-assist-extension && gemini extensions install .

Description: Displays the main help menu and index of available commands. Usage:

/java

Description: Creates or updates README.md for the analyzed Java project using either README.guidelines.md (if present) or the built-in defaults. Usage:

/java:readme

Notes:

• Only AI-managed blocks wrapped by <!-- AI:START --> and <!-- AI:END --> are updated; manual content stays untouched.
• Output follows a neutral, technical tone and defaults to a conservative structure when no guidelines file exists.

Description: Lints the API contract for standards compliance and consistency. Supports OpenAPI (YAML/JSON) or Java controller/DTO analysis. Usage:

/java:api:lint

Output:

• Contract source and location.
• Standards violations (MUST-FIX/WARN).
• Consistency drift (Dominant conventions vs deviations).
• Recommended actions.

Description: Analyzes Java stack traces to identify root causes and propose concrete fixes. Usage:

/java:stacktrace <paste_your_stacktrace_here>

Output:

• Root cause analysis.
• Most likely failing component.
• Recommended immediate checks and fixes.

Description: Smart code review assistant. Analyzes git diff for logical risks, security vulnerabilities, regressions, and missing tests. It avoids style nitpicks to focus on high-value feedback. Usage:

# Review current unstaged changes
/java:review

# Review changes against the previous commit
/java:review HEAD~1

Output:

• Risk assessment (High/Medium/Low).
• Evidence from the code.
• Recommended actions (Must-do, Should-do).

Description: Analyzes project dependencies (Maven/Gradle). Checks for version conflicts, outdated libraries, and known security vulnerabilities. Usage:

/java:deps

Description: Enforces architectural boundaries. Currently focuses on the rule that DTO types must not appear in Service method signatures. Why: This ensures business logic remains agnostic to the transport layer (REST, gRPC, etc.). Usage:

/java:boundary

Output:

• Confirmed violations (Service methods accepting/returning DTOs).
• Suspected violations.
• Refactoring recommendations.

1. Safety First: We verify before we act. Destructive commands require user confirmation.
2. No "Magic": We explain why a change is suggested. We don't generate massive blocks of code without understanding the context.
3. Context Aware: We read pom.xml or build.gradle first to tailor advice to your specific stack.

The java:readme command determines whether a README.guidelines.md file is available and applies its structure. If not, it falls back to a default order: Project Overview, Tech Stack, Build & Run, Project Structure, Configuration, and optional Limitations/Notes. Only the AI-managed block below is updated automatically; anything outside remains manual.

TODO: Summarize the analyzed Java project's purpose based on build configuration and visible source layout.

TODO: Note the detected build tool (Maven/Gradle), Java version, and frameworks (e.g., Spring Boot, Quarkus) inferred from dependencies.

TODO: Provide the exact build/run commands observed (e.g., ./mvnw spring-boot:run, ./gradlew quarkusDev). Leave TODO if not discoverable.

TODO: Outline key modules or directories in the repository using visible paths.

TODO: List main configuration files (e.g., application.properties, application.yml) and any notable settings surfaced in the codebase.

TODO: Capture known constraints or gaps; if unknown, keep TODO.

To verify that java:readme produced an English README with non-empty AI-managed content and markers, run:

./scripts/readme-validation.sh

• GEMINI.md: System instructions and agent persona.
• gemini-extension.json: Extension manifest.
• commands/: TOML definitions for each command.