Junie vs KiroUpdated 2026-03-16

SUMMARY

Junie (Agent) uses markdown configuration while Kiro (IDE) uses markdown. They differ on 3 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.

FEATURE COMPARISON

FeatureJunieKiro
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

FILE MAPPING

PurposeJunieKiro
Project instructions.junie/guidelines.md.kiro/steering/*.md
Project instructionsAGENTS.mdAGENTS.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

Kiro
.kiro/steering/*.md
markdown
---
inclusion: always
---

# Project Standards

## Stack
- TypeScript 5.x with Node.js 22
- AWS CDK v2 for infrastructure
- DynamoDB for data, S3 for assets

## Conventions
- Use ESM imports, not CommonJS
- Lambda handlers export a named `handler` function
- Use middy middleware for cross-cutting concerns
- All API responses follow JSON:API format

## Testing
- Unit tests with vitest
- Integration tests with aws-testing-library
- E2E tests use deployed staging environment

KEY DIFFERENCES

1. Hierarchy support

Junie: Not supported. Kiro: Supported.

2. Global config

Junie: Not supported. Kiro: Supported.

3. IDE integration

Junie: Agent. Kiro: Supported.

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use Junie, configure .junie/guidelines.md. If you use Kiro, configure .kiro/steering/*.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)