zkl2333 Codex CLI
OpenAI's terminal coding agent. Reads, edits, and runs code locally with configurable sandbox and approval controls. Built in Rust, open source.
Quick Reference
```bash
Interactive session
codex "your prompt here"
Non-interactive (scripting/CI)
codex exec "your prompt here" codex exec --json "prompt" # JSONL output codex exec -o result.txt "prompt" # Save last message
Code review
codex review # Review current branch vs main codex review --uncommitted # Review all uncommitted changes codex review --base develop # Review against specific branch codex review --commit abc123 # Review a specific commit
Session management
codex resume # Pick from recent sessions codex resume --last # Continue most recent codex fork --last # Fork most recent into new thread
Cloud tasks (experimental)
codex cloud exec --env ENV_ID "task" codex cloud list codex cloud apply TASK_ID codex cloud diff TASK_ID ```
Key Flags
| Flag | Short | Purpose |
|---|---|---|
| `--model` | `-m` | Select model (e.g. `gpt-5.3-codex`, `o3`) |
| `--sandbox` | `-s` | `read-only` / `workspace-write` / `danger-full-access` |
| `--ask-for-approval` | `-a` | `untrusted` / `on-failure` / `on-request` / `never` |
| `--full-auto` | Shortcut: `-a on-request -s workspace-write` | |
| `--image` | `-i` | Attach image(s) to prompt |
| `--search` | Enable live web search | |
| `--cd` | `-C` | Set the working directory for the `codex` command. This directory will be used as the base for operations by subcommands like `exec`, `review`, `cloud exec`, etc. This flag should be passed directly to the `codex` command. For example: `codex --cd /path/to/project review`. |
| `--add-dir` | Grant additional writable directories | |
| `--config` | `-c` | Override config value (e.g. `-c model="o3"`) |
| `--profile` | `-p` | Load named config profile |
| `--oss` | Use local model provider (LM Studio / Ollama) | |
| `--json` | (exec only) JSONL output | |
| `--output-last-message` | `-o` | (exec only) Write last message to file |
| `--yolo` | Bypass all approvals and sandbox (DANGEROUS) |
Approval Modes
- untrusted (default): Only trusted commands (ls, cat, sed…) run without asking. Others prompt user.
- on-failure: Run all commands freely. Only prompt if a command fails.
- on-request: Model decides when to ask.
- never: Never prompt. Failures go straight back to model.
Sandbox Modes
- read-only: No file writes, no network.
- workspace-write: Write only in workspace + specified dirs. Configurable network access.
- danger-full-access: Unrestricted. Use only in isolated environments.
Slash Commands (Interactive)
| Command | Purpose |
|---|---|
| `/model` | Switch model mid-session |
| `/permissions` | Adjust approval/sandbox settings |
| `/review` | Run code review |
| `/diff` | Show git diff including untracked files |
| `/compact` | Summarize conversation to free tokens |
| `/mention` | Attach file to conversation |
| `/new` | Start new conversation in same session |
| `/resume` | Resume saved conversation |
| `/fork` | Fork current conversation |
| `/init` | Generate AGENTS.md scaffold |
| `/mcp` | List MCP tools |
| `/status` | Show session config and token usage |
| `/ps` | Show background terminals |
| `/quit` | Exit |
Common Patterns
CI/CD Automation
```bash
Run task non-interactively with JSON output
codex exec --json --full-auto "fix all lint errors" | process_results.sh
Structured output with schema
codex exec --output-schema schema.json "analyze this codebase" ```
Code Review in CI
```bash codex review --base main --title "PR #42: Add auth" ```
Multi-Directory Projects
```bash codex --cd ./backend --add-dir ./shared "update the API" ```
Image-Driven Development
```bash codex -i mockup.png "implement this UI exactly" ```
Local OSS Models
```bash codex --oss --CPA ollama -m codellama "refactor this function" ```
Configuration
Config file: `~/.codex/config.toml` (user-level), `.codex/config.toml` (project-level).
For full configuration reference including all keys, MCP server setup, model providers, sandbox permissions, shell environment policies, and OpenTelemetry: see references/config-reference.md.
MCP Server Management
```bash codex mcp list # List configured servers codex mcp add # Add MCP server codex mcp remove # Remove MCP server codex mcp login # Authenticate with server codex mcp logout # Remove server credentials ```
Configure in config.toml:
```toml [mcp_servers.my-server] command = "npx" args = ["-y", "@my/mcp-server"] enabled = true ```