Getting Started

How to get Claude Code or Codex running on your own machine.

Before you start

The Toolkit describes the tools this setup relies on, including the shell, Git, GitHub, and Python, and why we chose them. Install Git and the GitHub CLI before setting up an agent; if any of it is unfamiliar, the agent can help once it is running.

Setting up a coding agent

Before installing, decide where the agent will run: your everyday machine, a separate user account, a virtual machine, or a dedicated machine. The more autonomy you plan to give it, the more that choice matters; see System-level control.

Install Claude Code, Codex, or both. They occupy the same place in this workflow: each can work locally from the terminal, integrate with an editor, and hand work to a cloud environment. The Coding Agents chapter compares their implementation details.

Both are available through several surfaces:

A desktop or web application, including remote and cloud work.
An editor extension, such as their VS Code integrations.
A command-line program, running in your terminal alongside your existing editor and tools.

We use the command line most often. It works in a wider variety of situations, gives the agent direct access to the surrounding toolchain, and tends to expose new capabilities first. This manual assumes the command line throughout; if you are using another interface, the equivalent is usually easy to find.

1. Install an agent

Follow the official instructions for Claude Code, Codex, or both. On macOS and Linux, their standalone installers are:

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

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

From a project directory, run claude or codex and complete the sign-in flow. Ask either one to explain the repository as a first read-only task.

2. Optional: install the DunnLab plugin for Claude Code

claude plugin marketplace add caseywdunn/dunnlab_code
claude plugin install dunnlab-code@dunnlab

This pulls the plugin from GitHub and caches it locally. To pick up changes later, run /plugin update dunnlab-code@dunnlab. Auto-update is off by default for third-party marketplaces like this one, so nothing arrives on its own unless you enable it under /plugin → Marketplaces.

Note that methods for installing plugins differ when using the desktop app or extension.

3. Verify the agent

For either agent, start in a Git repository and ask it to report its working directory, active instructions, permission boundary, and Git status. In Codex, /status and /permissions expose the session configuration. In Claude Code, /context and /permissions expose the corresponding information.

If you installed the DunnLab plugin, run the following Claude Code slash command to confirm everything is wired up:

/dunnlab-code:dunnlab-check

You should see a welcome message and a list of available skills. Plugin skills are namespaced by the plugin name; the bare /dunnlab-check also works as long as nothing else has claimed that name.

Once the agent is running, Managing Context describes Claude Code’s bundled skills and some additional plugins worth knowing about.