LESSON · 1 OF 2

What is Claude Code?

What is Claude Code?

Claude Code is an AI coding agent that lives in your terminal. You give it a goal in plain language; it plans, runs commands, reads and edits files, and reports back — the same loop a human engineer runs, automated.

Two ways to run it

ModeCommandWhen
Interactive consoleclaudeWorking on a task together, back and forth
Headless (print mode)claude -p "prompt"Scripts, pipelines, one-shot answers

Headless mode is the one that composes with everything else on Linux: its answer goes to stdout, so you can pipe it, redirect it, or call it from cron.

Already wired in this lab

Your VM has Claude Code preinstalled and authenticated against the lab's AI gateway with your personal budgeted key. The model is pinned by environment variables — claude-opus-4-8 by default, with sonnet and haiku aliases for lighter work. Nothing to configure.

Permissions in one sentence

By default Claude asks before it touches your files or runs commands; in headless mode you grant that up front with --permission-mode acceptEdits (file edits allowed) — you stay in charge of everything else.

Next: verify those prerequisites on this machine.

Spin up a fresh environment and practice live.
claude-code-ubuntu · fresh machine · ready in under a minute