Junie vs Zed | agentconfig.ing

Junie vs ZedComparisonUpdated 2026-03-16

SUMMARY

Junie (Agent) uses markdown configuration while Zed (Editor) 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

Feature	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	✗	✗
IDE integration	Agent	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	Junie	Zed
Project instructions	.junie/guidelines.md	Rules Library

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

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

Junie: Not supported. Zed: Supported.

2. Global config

Junie: Not supported. Zed: Supported.

3. IDE integration

Junie: Agent. Zed: Editor.

WHICH SHOULD I USE?

Recommendation

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