Junie vs Lovable | agentconfig.ing

Junie vs LovableComparisonUpdated 2026-03-16

SUMMARY

Junie (Agent) uses markdown configuration while Lovable (Platform) 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

Feature	Junie	Lovable	Notes
Config format	markdown	markdown
Hierarchy support	✗	✗	Whether config files can be placed at multiple directory levels
Global config	✗	✗	User-wide configuration outside any project
Project config	✓	✓
Subdirectory scoping	✗	✗	Config files in subdirectories that apply only to that subtree
File inclusion / imports	✗	✗	Ability to include or reference other files from config
Ignore file	✗	✗
IDE integration	Agent	Platform
Schema / structure	Free-form (Markdown)	Free-form (Markdown)	Whether config uses structured schema or free-form content
Git committed	✓	✓	Whether primary config files are intended to be version-controlled
Encoding	UTF-8	UTF-8

FILE MAPPING

Purpose	Junie	Lovable
Project instructions	.junie/guidelines.md	AGENTS.md

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

Lovable

AGENTS.md

markdown

# Project Instructions

## Stack
- React 19 with TypeScript
- Supabase for backend (auth, database, storage)
- TailwindCSS v4 + shadcn/ui components
- Vite for building

## Architecture
- Feature-based folder structure
- Each feature owns its components, hooks, and types
- Shared components in src/components/ui/
- All API calls go through src/lib/supabase.ts

## Conventions
- Use shadcn/ui components before creating custom ones
- Mobile-first responsive design
- Use Supabase RLS policies for authorization
- Prefer server-side filtering over client-side

## Brand
- Primary color: #6366F1 (indigo)
- Font: Inter for body, Cal Sans for headings
- Rounded corners (radius-lg) on all cards

KEY DIFFERENCES

1. IDE integration

Junie: Agent. Lovable: Platform.

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use Junie, configure .junie/guidelines.md. If you use Lovable, configure AGENTS.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