Junie vs VoidUpdated 2026-03-16

SUMMARY

Junie (Agent) uses markdown configuration while Void (IDE) uses markdown. They differ on 1 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.

FEATURE COMPARISON

FeatureJunieVoid
Config formatmarkdownmarkdown
Hierarchy support
Global config
Project config
Subdirectory scoping
File inclusion / imports
Ignore file
IDE integrationAgent
Schema / structureFree-form (Markdown)Free-form (Markdown)
Git committed
EncodingUTF-8UTF-8

SIDE-BY-SIDE CODE SAMPLES

Junie
.junie/guidelines.md
markdown
# Project Guidelines

## Language & Framework
- Kotlin with Spring Boot 3.x
- Gradle with Kotlin DSL
- JDK 21 with virtual threads

## Architecture
- Hexagonal architecture (ports & adapters)
- Domain events for cross-module communication
- CQRS for read-heavy endpoints

## Code Standards
- Follow Kotlin coding conventions
- Use data classes for DTOs
- Prefer sealed classes for domain errors
- Extension functions over utility classes

## Testing
- JUnit 5 with Kotest assertions
- Testcontainers for integration tests
- MockK for mocking (not Mockito)

## Build & Run
- Build: ./gradlew build
- Test: ./gradlew test
- Run: ./gradlew bootRun

Void
.void/rules/*.md
markdown
---
description: Python backend conventions
globs: "app/**/*.py"
auto_apply: true
---

# Backend Rules

## Stack
- Python 3.12 with FastAPI
- SQLAlchemy 2.0 with async sessions
- Alembic for migrations
- pytest for testing

## Conventions
- Use type hints on all function signatures
- Async endpoints by default
- Pydantic v2 models for request/response schemas
- Repository pattern for database access

## File Structure
- app/api/routes/ — API endpoints
- app/models/ — SQLAlchemy models
- app/schemas/ — Pydantic schemas
- app/services/ — Business logic

KEY DIFFERENCES

1. IDE integration

Junie: Agent. Void: Supported.

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use Junie, configure .junie/guidelines.md. If you use Void, configure .void/rules/*.md. Many projects include config files for multiple tools so each team member can use their preferred editor.

PORTABILITY TIP

sync-instructions.sh
bash
# Maintain a single source of truth:
cp AI-INSTRUCTIONS.md CLAUDE.md
cp AI-INSTRUCTIONS.md .cursorrules
cp AI-INSTRUCTIONS.md AGENTS.md

SEE ALSO

agentconfig.ing2026-03-16COMPARE(1)