How to migrate from Codex to Claude Code

aix is a CLI for defining, installing, and syncing AI editor configuration. If you are moving from Codex to Claude Code, this guide shows what aix can carry over, what the destination editor calls each feature, and where the destination config lands.

When you are ready to run the move, aix sync codex --to claude-code copies the supported config from Codex into Claude Code. Use the comparison below first so you know which names, paths, and support differences to expect.

If you want the aix-side definitions first, review rules , prompts , mcp , skills , hooks .

Run this migration

Preview the user-scope migration before writing files:
```
aix sync codex --to claude-code --dry-run
```
Read the preview for skipped or converted features, then run:
```
aix sync codex --to claude-code
```
Open Claude Code's generated files and compare them with the destination details below. Use --scope project when the source config is project-scoped.

What needs attention

Rules: Codex calls this "AGENTS.md", while Claude Code calls it "Rules".
Prompts: Claude Code keeps prompts more directly than Codex.
MCP: Codex and Claude Code put mcp in different project or user targets.
Skills: Codex and Claude Code put skills in different project or user targets.

How to use this guide

Read across a row to compare the source and destination terms, support, and targets.
Each scope line shows both what the editor supports and what aix writes today.
Open the destination editor page at the end if you need every path, note, and terminology detail.

The biggest changes are in rules, prompts, mcp.

Editor support

Supported The editor exposes that feature at that scope.
No support The editor does not expose that feature at that scope.

aix support

Native aix writes the editor's own format.
Adapter aix keeps the feature through an adapter or alternate representation.
No support aix does not write that feature for the destination today.

Use the Project scope and User scope rows to see where config lands at each level.

Feature comparison

Feature-by-feature differences from Codex to Claude Code.
Feature	Codex	Claude Code
Rules	AGENTS.md Project Editor Supported aix Native Path `AGENTS.md at the project root and selected subdirectories` User Editor Supported aix Native Path `~/.codex/AGENTS.md`	Rules Project Editor Supported aix Native Path `.claude/rules/*.md` User Editor Supported aix Native Path `~/.claude/CLAUDE.md`
Prompts	Skills Project Editor Supported aix Adapter Path `.agents/skills/prompt-{name}/` aix: Prompts are installed as instruction-only Agent Skills. User Editor Supported aix Adapter Path `~/.codex/skills/prompt-{name}/` aix: User-scoped prompts are also converted to skills.	Commands Project Editor Supported aix Native Path `.claude/commands/.md` User Editor Supported aix Native Path `~/.claude/commands/.md`
MCP	MCP servers Project Editor No support aix No support Editor: The editor does not expose this feature at this scope. aix: aix does not yet write Codex project MCP config. User Editor Supported aix Native Path `~/.codex/config.toml`	MCP servers Project Editor Supported aix Native Path `.mcp.json` User Editor Supported aix Native Path `~/.claude.json`
Skills	Skills Project Editor Supported aix Native Path `.agents/skills/{name}/` User Editor Supported aix Native Path `~/.codex/skills/{name}/`	Skills Project Editor Supported aix Native Path `.claude/skills/{name}/` User Editor Supported aix Native Path `~/.claude/skills/{name}/`
Agents	Agents Project Editor No support aix No support Editor: The editor does not expose this feature at this scope. aix: aix reports configured agents as unsupported for Codex. User Editor No support aix No support Editor: The editor does not expose this feature at this scope. aix: aix reports configured agents as unsupported for Codex.	Subagents Project Editor Supported aix Native Path `.claude/agents/.md` User Editor Supported aix Native Path `~/.claude/agents/.md`
Hooks	Hooks Project Editor Supported aix Native Path `.codex/hooks.json` User Editor Supported aix Native Path `~/.codex/hooks.json`	Hooks Project Editor Supported aix Native Path `.claude/settings.json` User Editor Supported aix Native Path `~/.claude/settings.json`