Junie vs ReplitComparisonUpdated 2026-03-16
SUMMARY
Junie (Agent) uses markdown configuration while Replit (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 | Replit |
|---|---|---|
| Config format | markdown | markdown |
| Hierarchy support | ✗ | ✗ |
| Global config | ✗ | ✗ |
| Project config | ✓ | ✓ |
| Subdirectory scoping | ✗ | ✗ |
| File inclusion / imports | ✗ | ✗ |
| Ignore file | ✗ | ✗ |
| IDE integration | Agent | Platform |
| Schema / structure | Free-form (Markdown) | Free-form (Markdown) |
| Git committed | ✓ | ✓ |
| Encoding | UTF-8 | UTF-8 |
FILE MAPPING
| Purpose | Junie | Replit |
|---|---|---|
| Project instructions | .junie/guidelines.md | replit.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
Replit
replit.md
markdown
# My Project
## Overview
This is a Next.js e-commerce storefront with Stripe payments, NextAuth
authentication, and a PostgreSQL database via Prisma ORM.
## Tech Stack
- Framework: Next.js 14 (App Router, server components by default)
- Database: PostgreSQL with Prisma ORM
- Auth: NextAuth.js with GitHub and Google providers
- Payments: Stripe Checkout and webhooks
- Styling: Tailwind CSS with shadcn/ui components
## Development Phase
Currently building the product catalog and cart system. Authentication
and payment flows are complete. Next up: order history and admin dashboard.
## Code Style
- TypeScript strict mode enabled
- Prefer server components; use "use client" only when needed
- Use server actions for mutations (app/actions/)
- Validate all inputs with Zod schemas
## Commands
- `npm run dev` — start development server on port 3000
- `npm run build` — production build
- `npm run db:push` — push Prisma schema to database
- `npm run db:seed` — seed database with sample data
- `npm test` — run Jest test suite
## External Resources
- Design system: https://ui.shadcn.com
- API docs: Stripe API at https://stripe.com/docs/api
KEY DIFFERENCES
Junie: Agent. Replit: Platform.
WHICH SHOULD I USE?
Choose based on your IDE/CLI preference. If you use Junie, configure .junie/guidelines.md. If you use Replit, configure replit.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
File references:
agentconfig.ing2026-03-16COMPARE(1)