Your First Session

Once Claude Code is installed, starting a session takes one command — and from there you talk to it like a colleague, in plain language. This lesson walks you through launching Claude Code in a real project, exploring the codebase, making a change, reviewing the diff, and wrapping up with a commit.

Start Claude Code

Navigate to any project directory in your terminal and run the claude command. That is all it takes to open an interactive session.

bash

cd /path/to/your/project
claude

You will see a prompt showing the current model and working directory. Type /help at any time to see available commands, or /exit (or Ctrl+D) to quit.

Ask your first question

Start by asking Claude to explain the project. You do not need to point it at any files — it reads them automatically as needed.

bash

what does this project do?
explain the folder structure
where is the main entry point?

No manual context needed

Claude Code reads your project files on its own. You never have to paste code into the prompt or tell it which files to look at — just ask your question and it figures out what to read.

Make your first change

Describe what you want in plain English. Claude will find the right file, plan the edit, and show you exactly what it intends to do before touching anything.

bash

add a hello world function to the main file
there's a bug where users can submit empty forms - fix it
add input validation to the user registration form

Claude locates the relevant file on its own
It shows you the proposed changes as a diff
It waits for your approval before writing anything
If tests exist, it can run them automatically

Review and accept edits

After Claude proposes a change you will see the diff inline. You can approve it, reject it, or ask Claude to adjust the approach before applying anything. For longer sessions where you trust the direction, you can enable 'Accept all' mode so edits apply without a prompt each time — press Shift+Tab to cycle through permission modes.

Always review before accepting

Claude is helpful but not infallible. Read the diff before you approve, especially for changes to core logic or configuration files. You can always ask it to explain a change: 'why did you modify that file?'

Keep the loop going

Once your changes look good, you can ask Claude to handle git as well — in the same conversational style.

bash

what files have I changed?
commit my changes with a descriptive message
create a new branch called feature/quickstart

You can keep building on the same session: ask for a refactor, request new tests, or have it review your own changes. Use the up-arrow key for history, Tab for command completion, and /clear to reset the conversation when you want a fresh start on a new task.

Key takeaways

Run claude inside your project directory to start. Ask questions in plain language — Claude reads your files automatically. Every file change is shown as a diff and requires your approval before it is applied. Git operations work the same way: just describe what you want. For the full quickstart reference, see code.claude.com/docs/en/quickstart.