01 | Codex App: Installation, Authentication, and a First Safe Task

Define the first lesson clearly

This lesson has three outcomes: Codex App starts and authenticates successfully; you open a suitable local project; and you complete one small, inspectable change with a clear permission boundary. The upstream guide treats Microsoft Store as the main Windows route and separately covers the official macOS route, system permissions, and developer tooling. The CLI can assist with installation or troubleshooting, but it is not the starting point for the desktop workflow.

Seeing an app icon is not the definition of success. Success means that you can enter a project, understand what the current thread may read or write, and inspect the result of a first task.

A safe first-start sequence

1. Authenticate and confirm the scope of your personal or organization account.
2. Open a small, clean project that can run and test. Do not use a production directory or a repository containing sensitive data for your first exercise.
3. Handle firewall prompts, PowerShell execution policy, WSL2, and development-tooling messages by symptom rather than repeatedly reinstalling.
4. Begin with a read-only request: ask for the project structure, test entry points, and likely verification commands.

On Windows, distinguish the desktop App, the native agent/PowerShell layer, and a WSL2 development environment. They can work together, but an issue in one layer does not automatically mean the App is incorrectly installed.

Make the first task small, explicit, and reversible

The upstream guide starts with a controllable task. State the goal, editable scope, protected areas, and verification method:

Read the project instructions and existing tests first.
Only fix empty-email validation in the login form; do not change APIs or dependencies.
Run the relevant tests, then list changed files and any remaining unverified risk.

The point is not to delegate more work at once. It is to build the habit of reading the plan, reviewing the diff, and checking verification evidence.

Completion checklist

• The App starts and authenticates.
• You can identify the current project and thread.
• You know where permission confirmation appears.
• You have completed one read-only analysis and one narrow write.
• You can inspect changes, run verification, and stop when the scope becomes uncertain.

In the first week, optimize for the loop of opening a project, describing work, reviewing changes, and verifying results—not for elaborate configuration.