codex

# OpenAI Codex CLI Agent Bridge Delegate code generation, editing, and explanation tasks to the OpenAI Codex CLI. Codex CLI runs GPT-4o in an agentic coding loop with sandboxed code execution. ## When to Use - User wants to generate code using OpenAI's GPT-4o model - Task requires code execution in a sandboxed environment - User wants an alternative to Claude Code using the OpenAI API - User wants to benchmark or compare code generation between providers - Task requires OpenAI-specific features or models ## How to Use ### 1. Install Codex CLI ```powershell # Requires Node.js 18+ npm install -g @openai/codex # Verify codex --version # Set API key $env:OPENAI_API_KEY = "sk-..." ``` ### 2. Run a coding task interactively ```powershell Set-Location "C:\Users\<you>\myproject" codex "Add input validation to all form fields in the React components" ``` ### 3. Non-interactive mode ```powershell # Auto-approve all edits (use with caution) codex --approval-mode auto-edit "Add JSDoc comments to all exported functions in src/" # Full auto mode (applies changes without confirmation) codex --approval-mode full-auto "Fix all ESLint errors in the project" ``` ### 4. Use a specific model ```powershell # Use GPT-4o (default) codex --model gpt-4o "Optimize the database query in src/db.js" # Use GPT-4o-mini for faster, cheaper tasks codex --model gpt-4o-mini "Add error handling to the fetch calls" ``` ### 5. Ask a coding question without editing files ```powershell # Question mode — returns explanation only codex --question "What does the middleware chain in src/app.ts do?" ``` ### 6. Generate code from scratch ```powershell # Create a new file/module codex "Create a TypeScript utility module with functions for: - Formatting currency (Indian Rupee) - Parsing date strings to Date objects - Debouncing function calls Save to src/utils/format.ts" ``` ### 7. Explain existing code ```powershell codex "Explain what the agentLoop.ts file does, focusing on the tool execution flow" ``` ## Examples **"Generate a REST API client for the GitHub API in TypeScript"** → Use step 6: `codex "Create a TypeScript GitHub API client with methods for: list repos, create issue, get PR. Save to src/github-client.ts"`. **"Fix all TypeScript compilation errors in the project"** → Use step 3 with `--approval-mode auto-edit` after reviewing what changes will be made. **"Explain how the authentication middleware works"** → Use step 5 or 7 in question mode — returns an explanation without modifying files. ## Cautions - `--approval-mode full-auto` applies all changes without confirmation — always run on a clean git branch - Codex CLI bills against your OpenAI API key — monitor usage at platform.openai.com/usage - `OPENAI_API_KEY` must be set in the environment before running any commands - Codex executes code in a sandbox but may read any files in the current directory — scope to the right project folder - For very large codebases, provide a focused scope (specific file or module) rather than asking it to scan the entire project