CODEX GUIDES

What do you want to do with Codex?

Choose a guide for the task you have now. Start with one small result, inspect it, and build from there.

A practical first path

  1. Understand the available workflows
  2. Install and verify your setup
  3. Complete a small task and run its test
  4. Review the change before keeping it

Start and sign in

  1. Start here

    Understand what Codex does

    Choose between the terminal, editor, desktop app, and cloud. Decide whether it fits your task.

  2. Set up

    Install and update Codex

    Set up Codex on macOS, Windows, or Linux and verify that the CLI is available.

  3. Try it

    Complete your first coding task

    Download a small practice project, fix one bug, and check the result with tests.

  4. Use the app

    Find your way around the desktop app

    Find the official download, choose your project and run location, and review changes in the app.

  5. Sign in

    Sign in and fix login problems

    Choose your ChatGPT account or API key, switch accounts, and finish a login that gets stuck.

Costs and usage

  1. Check costs

    Understand the cost before you pay

    Compare personal plans and separate the monthly fee, extra credits, and API bill.

  2. Check usage

    Check your usage and reset time

    Find what is left, understand why tasks use different amounts, and decide what to do at the limit.

Terminal and project setup

  1. Use the terminal

    Fix a small bug in the terminal

    Use a downloadable practice project to give Codex a task, inspect the edit, and check the result yourself.

  2. Look up a command

    Find the command you need

    See where to type terminal and slash commands, what they do, and how to check your version.

  3. Continue a session

    Return to a chat or try a new branch

    Find a saved session, continue yesterday’s work, or fork a conversation without confusing it with your files.

  4. Project instructions

    Give the project lasting instructions

    Write a short AGENTS.md file and check which rules Codex actually reads.

  5. Permissions

    Check what Codex can change

    Understand approvals and verify read-only and workspace access with a harmless test.

  6. Models and effort

    Choose a model for the task

    Check availability and compare reasoning effort with an answer you can verify.

  7. Configure

    Configure the Codex CLI

    Explore the configuration guide when you are ready to adjust how the CLI works.

Skills and integrations

  1. Skills

    Turn a repeated task into a skill

    Create a small test workflow, run it explicitly, and check failure and success.

  2. MCP tools

    Connect and test external tools

    Try local and HTTP tool services, inspect actual responses, and diagnose connection errors.

  3. Plugins

    Install a package and verify its skills

    Build a small local plugin, test activation, and check disabling and removal.

  4. Editors

    Find the correct editor integration

    Compare supported routes and account boundaries for VS Code, Cursor, JetBrains, Zed, and Xcode.

  5. VS Code

    Use Codex in VS Code

    Install the extension, verify context, and inspect a focused edit.

  6. Cursor integration

    Use Codex inside Cursor

    Distinguish the Codex extension from Cursor’s own agent.

  7. Custom gateways

    Connect a custom API gateway

    Check provider settings, Responses compatibility, and the difference between key and model errors.

Build, review, and script

  1. Website practice

    Build and test a small website

    Try a working demo, download its files, and follow a real defect through repair and browser checks.

  2. Code review

    Review a change and verify a finding

    Try a local review with a known failing test, then understand the GitHub and GitLab review routes.

  3. Security review

    Check a security finding against the code

    Choose a Security scan, inspect its scope and evidence, and verify a small repair.

  4. Worktrees

    Give a task its own working folder

    Create an isolated checkout, test the result, handle conflicts, and clean up without losing changes.

  5. Cloud

    Prepare a cloud environment

    Connect the intended repositories, check setup, and review hosted work.

  6. Scheduled tasks

    Schedule and inspect recurring work

    Test a prompt, check run conditions, and pause or stop a schedule.

  7. Subagents

    Divide work with clear boundaries

    Assign independent checks and verify the combined findings.

  8. Hooks

    Run a command when an agent event happens

    Record one prompt event, review its command, and verify what happens after a definition changes.

  9. SDK

    Control Codex from your program

    Try TypeScript and Python examples with events, continued conversations, and resumed threads.

  10. Non-interactive tasks

    Run a task from a script

    Send input, save structured output, and check success and failure before using a job in CI.

  11. API routes

    Choose the right programming interface

    Separate direct model requests, SDK tasks, and the App Server protocol before building an integration.

  12. Keep going

    Improve your Codex workflow

    Use the practical tips guide to make everyday coding requests clearer and easier to review.

Compare and troubleshoot

  1. App or CLI

    Choose the app or the terminal

    Match project organization, previews, scripts, reviews, and parallel work to your next task.

  2. Claude Code comparison

    Compare Codex and Claude Code

    Compare accounts, instructions, permissions, and accepted results.

  3. Cursor comparison

    Compare Codex and Cursor

    Identify the selected agent and compare a controlled workflow.

  4. Alternatives

    Compare alternatives and free limits

    Check current access rules, setup costs, and the limits of a free trial before switching tools.

  5. Troubleshooting

    Find the step that actually failed

    Use real command errors and final results to separate local input problems from task failures.