Checkpoint

checkpoint — Instant Undo for Claude Code

Auto-snapshots your files before each prompt. Revert instantly — no tokens wasted, no reimplementation.

Commands

/checkpoint or /cp — List all checkpoints

CLAUDE_SESSION_ID="${CLAUDE_SESSION_ID}" PROJECT_ROOT="${PWD}" node "${CLAUDE_SKILL_DIR}/../../scripts/store.js" list

Display the result as a formatted table:

#  | Time       | Files | Preview
---|------------|-------|--------
1  | 14:23:01   | 0     | session start
2  | 14:23:45   | 3     | Add auth to login page...
3  | 14:25:12   | 5     | Refactor the header comp...

/checkpoint undo or /cp undo — Undo last prompt's changes

CLAUDE_SESSION_ID="${CLAUDE_SESSION_ID}" PROJECT_ROOT="${PWD}" node "${CLAUDE_SKILL_DIR}/../../scripts/store.js" undo

This restores all files to their state at the most recent checkpoint (before the last prompt ran). Files created by the last prompt are deleted. A safety checkpoint is auto-created first so the undo itself can be undone.

Display result: "Restored to checkpoint #N. X files restored, Y new files removed."

/checkpoint undo N or /cp undo N — Undo to specific checkpoint

CLAUDE_SESSION_ID="${CLAUDE_SESSION_ID}" PROJECT_ROOT="${PWD}" node "${CLAUDE_SKILL_DIR}/../../scripts/store.js" restore N

Replace N with the checkpoint number. Restores all tracked files to their state at checkpoint N. All files created after checkpoint N are deleted.

Display result: "Restored to checkpoint #N. X files restored, Y new files removed."

/checkpoint diff N or /cp diff N — See what changed since checkpoint N

CLAUDE_SESSION_ID="${CLAUDE_SESSION_ID}" PROJECT_ROOT="${PWD}" node "${CLAUDE_SKILL_DIR}/../../scripts/store.js" diff N

Shows which files differ between checkpoint N and the current state, with line count changes.

/checkpoint status or /cp status — Show checkpoint stats

CLAUDE_SESSION_ID="${CLAUDE_SESSION_ID}" PROJECT_ROOT="${PWD}" node "${CLAUDE_SKILL_DIR}/../../scripts/store.js" status

Shows: session ID, number of checkpoints, tracked files count, storage used.

/checkpoint clean or /cp clean — Clean up all checkpoints

CLAUDE_SESSION_ID="${CLAUDE_SESSION_ID}" PROJECT_ROOT="${PWD}" node "${CLAUDE_SKILL_DIR}/../../scripts/store.js" cleanup

Removes all checkpoint data for the current session.

Natural Language Triggers

When the user says things like:

• "undo that" / "revert that" / "go back" → run /checkpoint undo
• "undo to before the auth changes" → list checkpoints, find the right one, run /checkpoint undo N
• "what did you change?" → run /checkpoint diff with the last checkpoint
• "I don't like these changes" → run /checkpoint undo

How It Works

1. SessionStart hook initializes the checkpoint session
2. UserPromptSubmit hook creates a checkpoint before each prompt (snapshots all tracked files)
3. PreToolUse hook watches Write/Edit calls and registers target files for tracking
4. Undo = copy snapshot files back + delete newly created files
5. Every undo creates a safety checkpoint first (so you can undo the undo)

Auto-Expiry

Old checkpoints are automatically pruned to prevent unbounded disk growth. After each new checkpoint is created, if the total count exceeds the limit, the oldest checkpoints are removed.

• Default limit: 50 checkpoints per session
• Configure via environment variable: set CHECKPOINT_MAX to a custom number (e.g. CHECKPOINT_MAX=100)
• Pruned checkpoint directories are deleted from disk immediately
• The manifest is updated to reflect the removal

Important Notes

• Checkpoints only track files Claude modifies — not the entire project
• Storage is in ~/.claude-checkpoints/<session-id>/
• Checkpoints persist for the session lifetime (up to the CHECKPOINT_MAX limit)
• Works with or without git — completely independent
• Zero token cost to undo — it's just file copies