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Keep a session on track

Beginner · Lesson 4 of 5 · about 20 minutes · Needs: Your first change, from request to commit · Verified against Claude Code v2.1.292 (stable) on 2026-10-15

Goal

By the end of this lesson you can keep a session on track: see how full its context is, clear or compact it, rewind a change, and resume an earlier conversation.

You need

  • Your copy of the practice template with no uncommitted changes, and Node.js LTS (a Codespace on your copy has it). To practice in one of your own repositories instead, keep the template copy as well: the check runs from it. Set up the repository's .practice/ folder as lesson 1 describes, if you haven't yet. Start that repository with no uncommitted changes too: commit them, or set them aside with git stash push --include-untracked.
  • Usage: light.

The idea

Everything in a conversation, your prompts, Claude's replies and every file it read, sits in the session's context window. The window is large but not endless, and a long, wandering conversation leaves Claude less room for the work that matters now (Explore the context window). Five commands keep it in hand (Commands):

Command What it does
/context Shows how full the context window is, as a colored grid
/compact Summarizes the conversation so far, to free space
/clear Starts a new conversation with empty context
/rewind Goes back to an earlier prompt, restoring the code, the conversation or both
/resume Picks up an earlier conversation

Compact when you want to keep going on the same task; clear when you start a different one. Rewind when a change went the wrong way (Checkpointing).

Worked example

  1. Start claude in your practice copy and type /context. The grid shows how much of the window is used, broken down by category, including your messages and any memory files, such as CLAUDE.md, that loaded (Explore the context window). Your practice copy has no CLAUDE.md yet, so you may see no memory files; lesson 5 adds one.

  2. Fill it a little:

    Explain how src/check-links.js decides that a link is broken.

    Run /context again: the messages part has grown.

  3. Compact, telling Claude what to keep:

    /compact keep what we learned about check-links.js

    The conversation is replaced by a summary: in /context the messages part shrinks and free space grows. After one short question there is little to summarize, so the change is small; compacting pays off when a conversation gets long.

  4. Make a change to undo. Rewind can't undo changes Claude makes by running commands (see Watch out), so the prompt asks for its file editing tool. Approve the edit if Claude asks:

    In src/cli.js, change the success message to "All relative links are fine." Use your file editing tool, not a shell command.

    In a second terminal in the same folder, save what git sees:

    git status --porcelain > .practice/b-4-before-rewind.txt

    The file lists src/cli.js.

  5. Rewind. Type /rewind, or press Esc twice with an empty prompt. Pick the prompt from step 4 and choose Restore code and conversation. If the menu offers only Restore conversation, the summarize options and Never mind, Claude changed the file with a command, which rewind can't undo: choose Never mind, press Esc to close the menu (Interactive mode), run git restore src/cli.js in the second terminal, and repeat step 4.

    Once the code is restored, save what git sees in the second terminal:

    git status --porcelain > .practice/b-4-after-rewind.txt

    This file is empty: the edit is gone. If a diff panel is open beside the conversation, it may still show the edit: Claude Code refreshes the panel each time Claude edits a file or runs a shell command (Interactive mode). The empty file shows what git sees.

  6. The rewind put your step 4 prompt back in the input box, so anything you type now is added to it. Press Esc twice quickly to clear it. Then type /clear. The conversation starts over with empty context, and the old one stays available.

  7. Type /exit, then reopen the most recent conversation in this folder (Manage sessions):

    claude --continue

    If it opens the empty conversation from step 6, run /resume and pick the earlier one. Inside a session, /resume with no argument opens a picker of earlier conversations. The conversation you pick may still show the edit you rewound, because it was saved before the rewind. Your files stay as the rewind left them (git status --porcelain prints nothing), so don't ask Claude to make the edit again. If Claude offers to redo the rewound edit, say no.

Your turn

Repeat the example in your practice copy, or your own repository:

  1. Run /context, ask one question about the code, and run /context again.
  2. Run /compact with a sentence about what to keep.
  3. Ask for a small edit to one file, ending the prompt with "Use your file editing tool, not a shell command.", and approve it if Claude asks. Save git status --porcelain > .practice/b-4-before-rewind.txt.
  4. Rewind that prompt with Restore code and conversation, and save git status --porcelain > .practice/b-4-after-rewind.txt.
  5. Press Esc twice quickly to clear the restored prompt, then run /clear, then /exit, then claude --continue.

Check

You are done when all of these are true:

  • .practice/b-4-before-rewind.txt lists the file Claude changed: cat .practice/b-4-before-rewind.txt.
  • .practice/b-4-after-rewind.txt lists no files: cat .practice/b-4-after-rewind.txt prints nothing.
  • Self-check (not tested): you can say when you'd use /compact and when /clear.

Run npm run check -- b-4 in your practice copy. In your own repository, run npm run check -- b-4 --dir <your repo> from your practice copy instead.

If the first file lists nothing, you saved it before the edit was made; make the edit again, save the file after it, then rewind again. If the second file still lists the file Claude changed, rewind that prompt with an option that restores code, then save the second file again. When the menu no longer lists that prompt (after Restore conversation) or offers no option that restores code (Claude used a command), run git restore <file> and repeat Your turn steps 3 and 4 instead. Files you changed before the lesson also stay listed, because rewind can't undo them: commit them or set them aside with git stash push --include-untracked, then save the second file again.

Watch out

  • Rewind undoes only the edits Claude made with its file editing tools. Changes made by commands it ran, such as deleting a file with rm, stay (Checkpointing); commit your work so git can bring it back.

Go further

Sources: Commands · Explore the context window · Checkpointing · Interactive mode · Manage sessions

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