Claude Code and Codex on Mac: installation and first task

Before you install

Have a Mac, an internet connection, Terminal and access to the agent you choose. Start with one; you do not need both immediately. Check the provider’s current account access, sign-in options and terms.

This guide covers the command-line versions, or CLIs. The providers have separate guides for graphical apps. Denny Agents requires Apple Silicon M1 or later and macOS 13 or later; check each agent’s own requirements separately.

Claude Code system requirements · Official Codex CLI guide.

1. Install Claude Code

Open Terminal. The native installation command in Anthropic’s official quickstart is:

curl -fsSL https://claude.ai/install.sh | bash

When installation finishes, open a new Terminal window and check:

claude --version

You should see a version number. Run claude in your chosen folder and follow the browser sign-in prompts. Agent access depends on your account; a Denny license does not provide that access.

2. Install Codex CLI

OpenAI publishes a native installer for macOS. The command in the official OpenAI documentation is:

curl -fsSL https://chatgpt.com/codex/install.sh | sh

Open a new Terminal window afterwards. In a project directory, run codex and choose Sign in with ChatGPT or another offered method.

Codex CLI works with your project files. Choose access and permissions in the agent. Check OpenAI account terms and usage limits separately from your Denny license.

3. Give the agent a small job

A separate practice folder makes the first result easy to find. These commands create one under your home folder and enter it:

mkdir -p ~/Projects/denny-agent-demo
cd ~/Projects/denny-agent-demo

Start claude or codex here. Try this task:

Create README.md with a plan for a portfolio page: three sections and the purpose of each. Change only this file. Install nothing and publish nothing. Finish by listing what you created.

This is a practice prompt, not a record of a comparison we ran. The goal is a small file you can read and assess yourself.

4. Inspect the result

Open README.md in an editor or Finder. Are there three sections? Are their purposes clear? Were unexpected files created? If the result misses something, give a specific correction in the same session.

For a real project, inspect the file changes and run that project’s checks as well. A “done” message does not establish that the result works. Having the CLI installed also does not establish that it is signed into the right account or running in the right project.

5. Bring your agents into the Denny notch

Once the agent works independently, follow the Denny Agents setup guide. Its agents section brings together usage windows, chats, sessions, events and permission requests.

The free edition includes an overview, usage limits and everyday tools. The full edition, activated with its own Agents key, adds agent control and Office. AI subscriptions and VPS hosting are separate. Denny Agents is made in Russia by AFTEAM.

For project-based work on your own server, continue with the self-hosted AI Office guide. A server is not needed for this first local task.

If the first run does not work

What you see	What to check
`command not found`	Confirm installation finished, open a new Terminal window and check PATH against the provider’s guide.
The command starts, but sign-in fails	Check account availability, the offered sign-in method and connectivity. Reinstalling Denny does not change provider access.
The agent cannot see the expected files	Check the session’s working folder. Your practice folder and real project are different directories.
Denny usage limits are missing or stale	Check the connected source and update time. Missing data does not mean no remaining allowance.

Quick answers

Do I need Node.js?

The commands above use native installers. Other installation methods can have different dependencies; follow their provider documentation.

Do I need full Denny to install an agent?

Agents install separately. Denny Agents has a free edition for the overview and usage limits; control and Office belong to its full edition.

Can I use just one agent?

Yes. Review a first result with one tool, then add another when you have a specific comparison to make.

Sources and check date

Commands and links checked on 5 November 2026. We did not run installers or send paid agent requests for this article. You can try the practice prompt yourself.

Claude Code and Codex on Mac: from installation to a first task