Begin in a practice folder
By the end, you will make a small code change, read its diff and test the interface. Desktop Code works with folders, tools and permissions; it is not Chat with an attachment.
Documentation checked on September 30, 2026 describes Local, Cloud, SSH or WSL depending on system. Start Local in a separate folder, not a live product. Desktop Code needs no separate CLI installation for its interface; the Windows local workflow requires Git according to the source.
Prepare one small file
Save index.html and preserve a copy:
<!doctype html>
<html lang="en">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<title>Practice course</title>
<h1>Practice course</h1>
<ul><li>Write a request</li><li>Check a source</li><li>Improve a draft</li></ul>
<p>Date not yet set.</p>
</html>
No private data, secrets, external services or login are needed. Select this folder, not your main work directory.
Start in Plan
Choose Code, correct destination and Plan if available. Plan investigates and proposes without editing source code but can run investigative commands. Manual asks about edits and commands; Accept edits automatically approves some edits. Do not select Bypass permissions for learning.
Inspect only index.html in the practice folder.
Plan a button that hides and shows the unit list.
Keep title, three units and “Date not yet set.” unchanged.
Do not edit yet, install packages, use the network or publish.
Inspect discovered files and proposed writes. Stop if another folder is selected or a framework is proposed for one button.
Perform a limited change
After reviewing the plan, choose a limited execution mode:
Implement the plan in index.html only.
Add a keyboard-accessible Show/hide units button
with aria-expanded matching list visibility.
Do not add services, dependencies, storage or publication.
Finish with a diff and testing instructions.
Read actual actions at approval prompts. Deleting the source or writing outside the folder is unnecessary. Expected behavior: only list visibility changes; title and date remain visible. Code may vary, so test behavior rather than matching an example character for character.
Read the diff and inspect the page
Check file by file for removed units, external links or additional modifications. Few changed lines do not guarantee correctness.
Open HTML in Browser pane or a local browser. Click twice to hide and show. Test Tab then Enter or Space. Inspect narrow layout and focus. Check aria-expanded updates accordingly.
Review the change and report problems before making further fixes.
Check open/close behavior, keyboard use and preservation of source content.
Claude's review is additional evidence, not your only test. A good screenshot does not prove the button works.
Save and manage continuation
After testing, save. With Git, inspect status and diff before committing. No push, PR or auto-merge is needed for this exercise. A folder copy works for beginner practice but is not a replacement for real version control.
Parallel session names do not isolate files. Learn worktrees before running two writing tasks in one repository. Preview, terminal, editor and diff availability depend on version and environment.
Local Code scheduling requires an open app and awake computer according to the source; remote routines are different. This button exercise needs no recurring task.
Graded practice
Easy: plan only
Request a plan. Success: understand proposed writes and verify the source remains unchanged.
Intermediate: implementation and test
Add the button. Success: two clicks and keyboard activation work; controlling content survives.
Challenging: focused restoration
Find an unwanted diff change and restore only it from a copy or Git. Success: preserve another valid change without external publication.
Troubleshooting
Wrong folder: stop before writing and choose the destination again.
Button fails: inspect errors and both clicks, not only appearance.
Plan ran a command: planning does not mean no tools. Read command and permission state.
Unnecessary installation: return to dependency-free HTML for easier testing.
Auto-merge proposed: CI does not review every consequence. This exercise includes no merge.
Secret in file: remove it from practice and do not request its printing.
CLI chapters continue the same destination, diff and testing discipline through the terminal.