Setup guide · AI-assisted coding

Get a coding agent running on your laptop

By the end of this page you will have an AI coding agent installed, signed in, and waiting for its first task. Either tool below works; pick one and follow it at your own pace.

Time  ~15 minutes Tools  Claude Code or Codex Works on  Mac & Windows

Official pages: Claude Code  ·  Codex.

00 — Orientation

What you are installing, in one minute

A coding agent is the same kind of model as a chatbot, with a machine built around it so it can act, not just answer.

A chat window can only hand you text. An agent opens your files, runs your code, reads what happened, and fixes it, pausing for your approval along the way. That is the whole difference, and it is why the setup below is worth fifteen minutes.

The mental model

Think of a fast, very literal research assistant sitting at your computer. It types the commands; you make the decisions and check the result. Nothing happens on your machine without your yes.

01 — The distinction that matters

What can it touch?

Every way of using AI differs mainly in what it may reach. Where the work runs is also where your data goes.

How you use itYour filesRun your codeWhere it runs
Chat windowChatGPT / Claude— none— you run ityour browser
Agent on your laptopthis guide✓ reads & edits✓ runs & checksyour machine
Cloud agentruns on serversa copy on GitHub✓ on serversthe vendor's servers

This guide sets up the middle row: an agent on your own laptop.

02 — Pick a tool

Two agents, either one works

Both do the same job. Each comes as a terminal program and as an app, and either form works. This course does not require a specific one, so pick by what you can access, then use it all week.

Claude Code

by Anthropic

  • Sign in with an Anthropic account.
  • Needs Claude Pro ($20/mo) or Max, or pay-as-you-go API credits.
  • New API accounts get about $5 free credits to try it.
  • No student free tier.

Official page & docs →

Codex

by OpenAI

  • Sign in with a ChatGPT account.
  • Verified US/Canada students get $100 in free usage credits.
  • Or use ChatGPT Plus ($20/mo), which includes it.
  • The cheapest path if you are a student.

Official page & docs →

Credits vs a plan

Credits are a fixed amount of usage you spend as you go; the $100 student credits and Anthropic's $5 trial are credits, and they run out once used. A plan like ChatGPT Plus or Claude Pro is a flat $20 a month with a usage allowance that refreshes. For this course the $100 Codex credits are plenty, so as a student you need no plan at all.

Short version

If cost matters and you are a student, Codex is free with the student credits. If you already pay for Claude, Claude Code is right there. The rest of this course works exactly the same with either.

03 — Install

Install it

There are two ways to install, and either one works: the terminal program or the app. The terminal install comes first, the app install after it.

The terminal program

One line installs the tool, with nothing else needed. Choose your operating system, then run the line for the tool you picked.

  1. Open the Terminal app

    Press ⌘ Command + Space, type Terminal, and press Enter. A small text window opens.

  2. Install your tool with one line

    Neither installer needs any other software. Run the one for your chosen tool.

    Claude Code
    $ curl -fsSL https://claude.ai/install.sh | bash
    Codex
    $ curl -fsSL https://chatgpt.com/codex/install.sh | sh
  3. Start it and sign in

    Type claude or codex and press Enter. The first time, it opens your browser to sign in with your account.

    Terminal
    $ claude   # or: codex
Sign in to continue…
→ your browser opens; approve, and you land back here signed in.

    Approximate — the exact prompt differs by tool.

The app

Codex comes as an extension inside the VS Code editor, and Claude Code comes as a desktop app. Both open a project folder and take the same requests in plain English.

Codex
  1. Install VS Code

    Download it from code.visualstudio.com. It is the same on Mac and Windows.

  2. Add the Codex extension

    Open the Extensions panel on the left, search for Codex, and install the one published by OpenAI (id openai.chatgpt). A Codex icon appears in the sidebar.

  3. Sign in

    Click Continue with ChatGPT, using the same account as before. Then open your project folder and give it the same prompt you would type in the terminal.

Claude Code
  1. Download the desktop app

    Get the Mac or Windows installer from the Claude Code desktop app page. The app includes Claude Code, so installing the app is enough on its own.

  2. Sign in and open a project

    Launch the app, sign in with your Anthropic account, and open your project folder. Give it the same prompt you would type in the terminal.

If you have seen "npm install" online

Older guides install either tool with npm, which first needs Node.js. You do not need that path; both one-line installers above are self-contained and get you the same tool.

04 — The versions

Each tool comes in a few versions

They do the same job. The difference that matters is where the code runs: on your own computer, or on the vendor's servers. Pick whichever you prefer; the rest of this course works with any of them.

Claude Code
VersionRuns on
Terminal (command line)your computer
Desktop app · Mac & Windowsyour computer
Web · claude.ai/codethe cloud
Codex
VersionRuns on
Terminal (command line)your computer
VS Code extensionyour computer
Codex Cloud · chatgpt.com/codexthe cloud

The cloud versions run on the vendor's servers and work on a copy of your project from GitHub. The rest run on your own machine, on your local files. A free GitHub account is enough for either.

05 — Staying in control

Permission levels

Each tool runs at one of three levels, from look-only to no-guardrails. The question behind all of them: how much would you let a brand-new assistant do unsupervised?

Claude Code  cycle with Shift+Tab

Plan Mode

Looks and plans; changes nothing. Good for exploring or thinking first.

Normal · default

Reads, edits, and runs, but asks before each real action.

Auto-Accept

Same as Normal without the prompts. For trusted, repeat tasks.

Codex  set at launch or with the /permissions command

Ask for approval · default

Reads and answers; asks before every edit or command. Good for exploring or planning.

Approve for me

Edits and runs in your folder without asking; stops at the network.

Full access

Edits, runs, and reaches the network with no prompts. Rarely, with care.

Start in Ask for approval, and move to Approve for me for everyday work once you trust the agent. The apps offer the same levels in their own interface; see the Codex approvals docs and the Claude Code desktop app docs.

06 — Try it

Your first task

Point it at a small folder you do not mind experimenting on, and ask for something concrete. In the terminal, move into the folder, start the tool, and type your request. In the app, open the same folder and give the same request.

your-project
$ cd my-first-project
$ claude   # or: codex
› explain what the files in this folder do
The agent reads the folder and answers.
Good first asks

"Explain what this script does." · "Add comments to this file." · "What columns are in this dataset?"

07 — If a step fails

Common setup snags, and the fix

Setup problems are normal and quick to clear. The usual ones:

  • "command not found" after installing: close the terminal, open a new one, and try again. It just needs a fresh window to see the new tool.
  • The install line fails partway: check your internet and run it once more; most failures are a dropped connection.
  • Sign-in does not open a browser: copy the link it prints and open it in your browser yourself.
  • Still stuck: check the official pages linked at the top, or raise your hand and post to the course board.
Once it is running

You do not copy errors anywhere. The tool runs your commands, reads the errors itself, and fixes them. If something still looks wrong, just tell it in plain words.