// Use when user asks to leverage codex, gpt-5, or gpt-5.1 to implement something (usually implement a plan or feature designed by Claude). Provides non-interactive automation mode for hands-off task execution without approval prompts.
| name | codex-skill |
| description | Use when user asks to leverage codex, gpt-5, or gpt-5.1 to implement something (usually implement a plan or feature designed by Claude). Provides non-interactive automation mode for hands-off task execution without approval prompts. |
| allowed-tools | Read, Write, Glob, Grep, Task, Bash(cat:*), Bash(ls:*), Bash(tree:*), Bash(codex:*) |
You are operating in codex exec - a non-interactive automation mode for hands-off task execution.
Before using this skill, ensure Codex CLI is installed and configured:
Installation verification:
codex --version
First-time setup: If not installed, guide the user to install Codex CLI with command npm i -g @openai/codex or brew install codex.
Codex uses sandbox policies to control what operations are permitted:
Read-Only Mode (Default)
codex execWorkspace-Write Mode (Recommended for Programming)
--full-auto or -s workspace-write to enable file editingDanger-Full-Access Mode
-s danger-full-access or --sandbox danger-full-accessNote: The following commands include both documented features from the Codex exec documentation and additional flags available in the CLI (verified via codex exec --help).
Specify which model to use with -m or --model (possible values: gpt-5, gpt-5.1, gpt-5.1-codex, gpt-5.1-codex-max, etc):
codex exec -m gpt-5.1 "refactor the payment processing module"
codex exec -m gpt-5.1-codex "implement the user authentication feature"
codex exec -m gpt-5.1-codex-max "analyze the codebase architecture"
Control execution permissions with -s or --sandbox (possible values: read-only, workspace-write, danger-full-access):
codex exec -s read-only "analyze the codebase structure and count lines of code"
codex exec --sandbox read-only "review code quality and suggest improvements"
Analyze code without making any modifications.
codex exec -s workspace-write "implement the user authentication feature"
codex exec --sandbox workspace-write "fix the bug in login flow"
Read and write files within the workspace. Must be explicitly enabled (not the default). Use this for most programming tasks.
codex exec -s danger-full-access "install dependencies and update the API integration"
codex exec --sandbox danger-full-access "setup development environment with npm packages"
Network access and system-level operations. Use only when necessary.
codex exec --full-auto "implement the user authentication feature"
Convenience alias for: -s workspace-write (enables file editing).
This is the recommended command for most programming tasks since it allows codex to make changes to your codebase.
Use saved profiles from ~/.codex/config.toml with -p or --profile (if supported in your version):
codex exec -p production "deploy the latest changes"
codex exec --profile development "run integration tests"
Profiles can specify default model, sandbox mode, and other options.
Verify availability with codex exec --help
Specify a different working directory with -C or --cd (if supported in your version):
codex exec -C /path/to/project "implement the feature"
codex exec --cd ~/projects/myapp "run tests and fix failures"
Verify availability with codex exec --help
Allow writing to additional directories outside the main workspace with --add-dir (if supported in your version):
codex exec --add-dir /tmp/output --add-dir ~/shared "generate reports in multiple locations"
Useful when the task needs to write to specific external directories.
Verify availability with codex exec --help
codex exec --json "run tests and report results"
codex exec --json -s read-only "analyze security vulnerabilities"
Outputs structured JSON Lines format with reasoning, commands, file changes, and metrics.
codex exec -o report.txt "generate a security audit report"
codex exec -o results.json --json "run performance benchmarks"
Writes the final message to a file instead of stdout.
codex exec --skip-git-repo-check "analyze this non-git directory"
Bypasses the requirement for the directory to be a git repository.
codex exec resume --last "now implement the next feature"
Resumes the last session and continues with a new task.
โ ๏ธ WARNING: Verify this flag exists before using โ ๏ธ
Some versions of Codex may support --dangerously-bypass-approvals-and-sandbox:
codex exec --dangerously-bypass-approvals-and-sandbox "perform the task"
If this flag is available:
Verify availability first: Run codex exec --help to check if this flag is supported in your version.
Combine multiple flags for complex scenarios:
# Use specific model with workspace write and JSON output
codex exec -m gpt-5.1-codex -s workspace-write --json "implement authentication and output results"
# Use profile with custom working directory
codex exec -p production -C /var/www/app "deploy updates"
# Full-auto with additional directories and output file
codex exec --full-auto --add-dir /tmp/logs -o summary.txt "refactor and log changes"
# Skip git check with specific model in different directory
codex exec -m gpt-5.1-codex -C ~/non-git-project --skip-git-repo-check "analyze and improve code"
Only pause for user input when encountering:
For all other decisions, proceed autonomously using best judgment.
Always conclude with a structured summary:
โ Task completed successfully
Changes made:
- [List of files modified/created]
- [Key code changes]
Results:
- [Metrics: lines changed, files affected, tests run]
- [What now works that didn't before]
Verification:
- [Tests run, checks performed]
Next steps (if applicable):
- [Suggestions for follow-up tasks]
User: "Count the lines of code in this project by language" Mode: Read-only Command:
codex exec -s read-only "count the total number of lines of code in this project, broken down by language"
Action: Search all files, categorize by extension, count lines, report totals
User: "Use gpt-5 to fix the authentication bug in the login flow" Mode: Workspace-write Command:
codex exec -m gpt-5 --full-auto "fix the authentication bug in the login flow"
Action: Find the bug, implement fix, run tests, commit changes
User: "Let codex implement dark mode support for the UI" Mode: Workspace-write Command:
codex exec --full-auto "add dark mode support to the UI with theme context and style updates"
Action: Identify components, add theme context, update styles, test in both modes
User: "Have gpt-5.1 update all imports from old-lib to new-lib" Mode: Workspace-write Command:
codex exec -m gpt-5.1 -s workspace-write "update all imports from old-lib to new-lib across the entire codebase"
Action: Find all imports, perform replacements, verify syntax, run tests
User: "Analyze security vulnerabilities and output as JSON" Mode: Read-only Command:
codex exec -s read-only --json "analyze the codebase for security vulnerabilities and provide a detailed report"
Action: Scan code, identify issues, output structured JSON with findings
User: "Install the new payment SDK and integrate it" Mode: Danger-Full-Access Command:
codex exec -s danger-full-access "install the payment SDK dependencies and integrate the API"
Action: Install packages, update code, add integration points, test functionality
User: "Use codex to implement the API in the backend project" Mode: Workspace-write Command:
codex exec -C ~/projects/backend --full-auto "implement the REST API endpoints for user management"
Action: Switch to backend directory, implement API endpoints, write tests
User: "Refactor the database layer and log changes" Mode: Workspace-write Command:
codex exec --full-auto --add-dir /tmp/refactor-logs "refactor the database layer for better performance and log all changes"
Action: Refactor code, write logs to external directory, run tests
User: "Deploy using the production profile" Mode: Profile-based Command:
codex exec -p production "deploy the latest changes to production environment"
Action: Use production config, deploy code, verify deployment
User: "Analyze this legacy codebase that's not in git" Mode: Read-only Command:
codex exec -s read-only --skip-git-repo-check "analyze the architecture and suggest modernization approach"
Action: Analyze code structure, provide modernization recommendations
When errors occur:
If execution is interrupted: