OpenAI Codex CLI vs GooseUpdated 2026-03-16

SUMMARY

OpenAI Codex CLI (CLI) uses markdown configuration while Goose (CLI) uses text. They differ on 3 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.

FEATURE COMPARISON

FeatureOpenAI Codex CLIGoose
Config formatmarkdowntext
Hierarchy support
Global config
Project config
Subdirectory scoping
File inclusion / imports
Ignore file.codexignore
IDE integrationCLICLI
Schema / structureFree-form (Markdown)Free-form (Markdown)
Git committed
EncodingUTF-8UTF-8

FILE MAPPING

PurposeOpenAI Codex CLIGoose
Project instructionsAGENTS.md.goosehints
Project instructionsAGENTS.override.mdAGENTS.md
Settings / configuration~/.codex/config.tomlconfig.yaml

SIDE-BY-SIDE CODE SAMPLES

OpenAI Codex CLI
AGENTS.md
markdown
# AGENTS.md

## Project Overview

This is a Next.js 14 e-commerce application using the App Router,
Server Components, and Drizzle ORM with PostgreSQL.

## Code Conventions

- Use TypeScript strict mode throughout
- Prefer Server Components; use "use client" only when necessary
- Name files with kebab-case: `product-card.tsx`, not `ProductCard.tsx`
- Co-locate tests: `product-card.test.tsx` next to `product-card.tsx`

## Architecture

- `app/`           — Next.js App Router pages and layouts
- `components/`    — Shared UI components
- `lib/`           — Utilities, database client, auth helpers
- `actions/`       — Server Actions for mutations

## Testing

- Use Vitest for unit tests, Playwright for E2E
- Mock database calls using `lib/test-utils.ts` helpers
- Every new component needs at least one test

## Build Commands

```bash
pnpm dev          # Start dev server
pnpm build        # Production build
pnpm test         # Run Vitest
pnpm test:e2e     # Run Playwright
pnpm lint         # ESLint check
```
Goose
.goosehints
text
This is a Ruby on Rails 7.2 application with Hotwire/Turbo.

Database: PostgreSQL 16
Ruby version: 3.3.x
Node: 22.x (for asset pipeline)

Key commands:
- bin/rails server — start dev server
- bin/rails test — run test suite
- bin/rails db:migrate — run migrations

Conventions:
- Use ViewComponents for reusable UI
- Stimulus controllers for JS behavior
- System tests with Capybara + Playwright
- RuboCop for linting (run: bundle exec rubocop)

KEY DIFFERENCES

1. Config format

OpenAI Codex CLI: markdown. Goose: text.

2. Subdirectory scoping

OpenAI Codex CLI: Supported. Goose: Not supported.

3. Ignore file

OpenAI Codex CLI: .codexignore. Goose: Not supported.

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use OpenAI Codex CLI, configure AGENTS.md. If you use Goose, configure config.yaml. 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)