# Claude Code cheatsheet

> CLAUDE.md, /clear, plan mode, and the rest of the Claude Code habits the course uses, all on one page

This page summarises the small set of commands and habits to remember. We will
add to it during the semester, so check back rather than reading it once. For
installation and authentication, see [onboarding](https://comp.anu.edu.au/courses/comp4020-agentic-coding-studio/topics/onboard/).

## Starting a session

`cd` into the repo first, then run `claude`. The session's context starts where
you launch it, so launching from your home directory and then asking about a
project somewhere else is the most common self-inflicted wound of week 1.

- `Esc` interrupts a response mid-flight --- use it as soon as you see the agent
  heading somewhere you didn't intend, rather than waiting politely for it to
  finish
- `/help` lists the built-in commands; `/comp4020:help` lists the course skills
- the `comp4020:` prefix is the plugin's namespace, and dropping it can bite:
  `/doctor` is Claude Code's own health check while `/comp4020:doctor` checks
  your course setup, so the unprefixed one may report all-clear while your key,
  org membership and crit group are still unset
- you rarely need memorised commands: describe the outcome you want and let the
  agent pick the mechanism

## The working loop

For anything larger than a one-line change, use the same loop:

1. **explore** --- ask how the relevant part of the repository works and which
   files implement it
2. **plan** --- settle the intended change, its boundaries and how it will be
   verified
3. **implement** --- make one bounded change
4. **verify** --- inspect the diff, run the checks and use the rendered artefact

Planning is overhead. Ask directly if you can describe the diff in one sentence
and review it at a glance. Plan when the code is unfamiliar, the change crosses
several files or you are unsure of the approach.

Ask for evidence at the end: the command and its output, the diff, and what the
agent observed in the running artefact. “Done” is still a claim.

## CLAUDE.md

The standing rules the agent reads every turn. A project-level `CLAUDE.md` in
the repo root contains the codebase's commands, constraints and conventions. A
global one at `~/.claude/CLAUDE.md` contains your preferences across every
project.

Everything in there consumes context on every turn. Include rules you need
often, especially those you repeatedly type into the chat.

## /clear

The fresh start. `/clear` discards the conversation and begins a new one in the
same directory, keeping your `CLAUDE.md` and losing everything else.

Reach for it when a session has gone weird --- the agent is looping, defending
an earlier mistake, or still working from something you corrected twenty turns
ago. Failed attempts remain in a long session's context and can affect later
responses, so clearing and re-briefing usually works better than arguing. The
reasoning underneath this, and what to do besides clearing, arrives in week 4.

## Interrupt, rewind, or revert

Use `Esc` as soon as the work heads in the wrong direction. The conversation is
preserved, so explain the correction and continue.

Press `Esc` twice or run `/rewind` to return to an earlier Claude Code
checkpoint. Checkpoints cover conversation state and edits made through Claude's
editing tools; they do not replace git. Use git when the repository history is
the source of truth, especially after commands or other programs changed files.

## Continue or resume

Use `claude --continue` to reopen the most recent session and `claude --resume`
to choose an earlier one. A resumed session should still be one coherent
workstream. Clear the context or start a new session when the job changes.

## Model and effort

`/model` picks the model for the session and `/effort` picks its reasoning
budget. Use the pickers rather than memorising a list that will change.

Both are cost levers, and your course credits are capped weekly. Keep the
model's default for ordinary work; lower it for short, scoped jobs where speed
and cost matter more, and raise it deliberately for hard debugging. Running a
heavy model at high effort on a one-line fix is how a week's allowance can be
consumed before the crit. `/comp4020:balance` reports your usage, and the
[LLM access page](https://comp.anu.edu.au/courses/comp4020-agentic-coding-studio/topics/llm-access/) covers the allocation itself.

## Plan mode

Have the model plan before it builds. Plan mode restricts the agent to reading
and proposing, making no edits until you accept the plan. You can therefore
correct a misread task before it changes any files.

Use it when the code is unfamiliar, the change crosses several files or you are
unsure of the approach. For a change you can describe and review at a glance,
ask directly. This is the informal version of the practice covered in week 2,
when you start interrogating the brief and spec before you build.

## Permissions

Permissions are part of the harness. Approve a capability because its scope is
appropriate, not because the prompt has become annoying. Prefer narrowly
allowing repeatable project commands such as the test or build script. The
[software and platforms page](https://comp.anu.edu.au/courses/comp4020-agentic-coding-studio/topics/software-and-platforms/#permission-modes-and-the-yolo-policy)
sets the course policy for broader modes.

Source: <https://comp.anu.edu.au/courses/comp4020-agentic-coding-studio/topics/claude-code-cheatsheet/>\
Licence: [CC-BY-NC-SA-4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/)\
Cite as: Swift, B. (2026). _COMP4020/COMP8020 Agentic Coding Studio_ [Course materials]. ANU School of Computing. https://doi.org/10.5281/zenodo.21395760
