JetBrains AI / Junie vs Zed

JetBrains AI / Junie vs ZedComparisonUpdated 2026-03-16

SUMMARY

JetBrains AI / Junie (IDE) uses markdown configuration while Zed (Editor) uses markdown. They differ on 4 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.

FEATURE COMPARISON

Feature	JetBrains AI / Junie	Zed	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	.aiignore	✗
IDE integration	✓	Editor
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	JetBrains AI / Junie	Zed
Project rules	.aiassistant/rules/*.md	.rules
Settings / configuration	.noai	.zed/settings.json

SIDE-BY-SIDE CODE SAMPLES

JetBrains AI / Junie

.aiassistant/rules/*.md

markdown

# Kotlin Conventions

## Language Features
- Use Kotlin 2.x with coroutines for async work
- Prefer data classes for DTOs and value objects
- Use sealed classes/interfaces for domain errors
- Extension functions over utility classes

## Spring Boot
- Constructor injection (no field injection)
- Use @ConfigurationProperties over @Value
- Prefer WebFlux for reactive endpoints
- Use Spring Security with method-level security

## Testing
- JUnit 5 with Kotest assertions
- MockK for mocking (not Mockito)
- Testcontainers for integration tests
- Use @Nested for test organization

Zed

.rules

markdown

# Project Rules

## Stack
- TypeScript 5.x with strict mode
- React 19 with Server Components
- Tailwind CSS v4
- Drizzle ORM with PostgreSQL

## Code Style
- Prefer named exports over default exports
- Use "use client" directive only when interactivity is required
- Colocate tests in __tests__ directories next to source files
- Use Zod for all runtime validation

## Architecture
- App Router with nested layouts in app/
- Server actions in app/actions/
- Database schema in db/schema.ts
- Shared utilities in lib/

## Commands
- Dev server: pnpm dev
- Type check: pnpm typecheck
- Test: pnpm test
- Lint: pnpm lint

KEY DIFFERENCES

1. Hierarchy support

JetBrains AI / Junie: Not supported. Zed: Supported.

2. Global config

JetBrains AI / Junie: Not supported. Zed: Supported.

3. Ignore file

JetBrains AI / Junie: .aiignore. Zed: Not supported.

4. IDE integration

JetBrains AI / Junie: Supported. Zed: Editor.

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use JetBrains AI / Junie, configure .aiassistant/rules/*.md. If you use Zed, configure .rules. 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