Bolt vs JunieUpdated 2026-03-16

SUMMARY

Bolt (Platform) uses text configuration while Junie (Agent) uses markdown. They differ on 2 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.

FEATURE COMPARISON

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

FILE MAPPING

PurposeBoltJunie
Project instructions.bolt/prompt.junie/guidelines.md
Project instructionsAGENTS.mdAGENTS.md

SIDE-BY-SIDE CODE SAMPLES

Bolt
.bolt/prompt
text
You are building a SaaS dashboard application.

Stack: Remix with TypeScript, Prisma ORM, PostgreSQL, TailwindCSS.

Key rules:
- Use server loaders for data fetching, not client-side fetch
- All forms use Remix Form with progressive enhancement
- Use Prisma for all database operations
- Style with TailwindCSS utility classes, no custom CSS
- Components go in app/components/, routes in app/routes/
- Use zod for form validation on both client and server

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

KEY DIFFERENCES

1. Config format

Bolt: text. Junie: markdown.

2. IDE integration

Bolt: Platform. Junie: Agent.

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use Bolt, configure .bolt/prompt. If you use Junie, configure .junie/guidelines.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)