feat(codex): add Codex integration with generate command

CHANGELOG.md

@@ -6,6 +6,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased]
 
+### Added
+- Codex integration: `agents/codex/AGENTS.md` flat entry point (all rules inlined)
+- `ai-rules generate` command: resolves `@rules/` imports and writes a flat file
+  for agents without native import support (`supports_imports = false`)
+- `src/ai_rules/generator.py`: `resolve_imports()` and `generate_flat_file()` functions
+- `agents.toml`: Codex agent registered (`install_dir = ~/.codex`, no import support)
+- `tests/test_generator.py`: 7 tests for the generator module
+- `rules/cli.md`: require shell completion for every CLI tool
+- `rules/commits.md`: prefer detailed commit messages
+
 ## [0.3.1] - 2026-03-26
 
 ### Added

README.md

@@ -10,17 +10,20 @@ supported AI assistants.
 
 ## Supported assistants
 
-| Key      | Assistant    | Config file               |
-|----------|--------------|---------------------------|
-| `claude` | Claude Code  | `agents/claude/CLAUDE.md` |
+| Key      | Assistant    | Config file                   | Import support |
+|----------|--------------|-------------------------------|----------------|
+| `claude` | Claude Code  | `agents/claude/CLAUDE.md`     | native         |
+| `codex`  | Codex        | `agents/codex/AGENTS.md`      | flat file      |
 
 ## Structure
 
 ```
 ai-rules/
 ├── agents/
-│   └── claude/
-│       └── CLAUDE.md       # Claude Code entry point (imports rules via @rules/)
+│   ├── claude/
+│   │   └── CLAUDE.md       # Claude Code entry point (imports rules via @rules/)
+│   └── codex/
+│       └── AGENTS.md       # Codex entry point (flat file, generated via `ai-rules generate`)
 ├── rules/                  # Shared rule files by topic
 │   ├── principles.md
 │   ├── language.md
@@ -89,10 +92,11 @@ Options:
   --help          Show this message and exit.
 
 Commands:
-  list     List available agents.
-  status   Show installation status for one or all agents.
-  install  Install rules for one or all agents.
-  update   Update installation for one or all agents.
+  list      List available agents.
+  status    Show installation status for one or all agents.
+  install   Install rules for one or all agents.
+  update    Update installation for one or all agents.
+  generate  Generate flat rule files for agents without native import support.
 ```
 
 ### Examples
@@ -114,6 +118,10 @@ ai-rules install claude
 # Dry run
 ai-rules install --dry-run
 
+# Regenerate flat files for agents without native import support
+ai-rules generate
+ai-rules generate codex
+
 # Shell completion (bash/zsh/fish)
 ai-rules --install-completion
 ```
@@ -131,6 +139,17 @@ For each declared link in `agents.toml`, `ai-rules install`:
 | `~/.claude/CLAUDE.md`      | `agents/claude/CLAUDE.md`         |
 | `~/.claude/rules`          | `rules/`                          |
 | `~/.claude/settings.json`  | `settings.json`                   |
+| `~/.codex/AGENTS.md`       | `agents/codex/AGENTS.md`          |
+
+### Agents without native import support (Codex)
+
+Codex does not support `@rules/` imports natively. Its entry point is a flat
+file generated from the Claude entry point with all imports resolved inline.
+Regenerate it after updating any rule file:
+
+```bash
+ai-rules generate codex
+```
 
 ## Development
 

TODO.md

@@ -3,10 +3,10 @@
 Improvements and additions to consider for future iterations of this config.
 
 ## Codex integration
-- [ ] Add `agents/codex/AGENTS.md` entry point (flat file — no @rules/ import support)
-- [ ] Add `generate` command to CLI: concatenate rules/ into a flat file for agents without native import support
-- [ ] Register Codex agent in `agents.toml`
-- [ ] Add tests for generate command and Codex agent
+- [x] Add `agents/codex/AGENTS.md` entry point (flat file — no @rules/ import support)
+- [x] Add `generate` command to CLI: concatenate rules/ into a flat file for agents without native import support
+- [x] Register Codex agent in `agents.toml`
+- [x] Add tests for generate command and Codex agent
 
 ## Naming conventions
 - [ ] Add naming conventions for other languages (JavaScript/TypeScript, Python, Go...) in `rules/naming.md` as they become relevant in projects

agents.toml

@@ -27,3 +27,13 @@ supports_imports = true
   [[agents.claude.links]]
   source = "settings.json"
   target = "settings.json"
+
+[agents.codex]
+name             = "Codex"
+entry_point      = "agents/codex/AGENTS.md"
+install_dir      = "~/.codex"
+supports_imports = false
+
+  [[agents.codex.links]]
+  source = "agents/codex/AGENTS.md"
+  target = "AGENTS.md"