Junie vs WindsurfUpdated 2026-03-16

SUMMARY

Junie (Agent) uses markdown configuration while Windsurf (IDE) uses markdown. They differ on 5 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.

FEATURE COMPARISON

FeatureJunieWindsurf
Config formatmarkdownmarkdown
Hierarchy support
Global config
Project config
Subdirectory scoping
File inclusion / imports
Ignore file.codeiumignore
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

Windsurf
.windsurf/rules/*.md
markdown
---
trigger: glob
globs: "**/*.test.ts"
---

# Testing Conventions

- Use Vitest as the test runner
- Colocate test files next to source files
- Use describe blocks organized by function/component name
- Prefer userEvent over fireEvent in component tests
- Mock external services; never hit real APIs in unit tests

KEY DIFFERENCES

1. Hierarchy support

Junie: Not supported. Windsurf: Supported.

2. Global config

Junie: Not supported. Windsurf: Supported.

3. Subdirectory scoping

Junie: Not supported. Windsurf: Supported.

4. Ignore file

Junie: Not supported. Windsurf: .codeiumignore.

5. IDE integration

Junie: Agent. Windsurf: Supported.

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use Junie, configure .junie/guidelines.md. If you use Windsurf, configure .windsurfrules. 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)