# Proposal: @suaveplan/undo

**Change ID:** enterprise-undo  
**Date:** 2026-04-24  
**Status:** Shipped

## Summary

Implement the `@suaveplan/undo` package — a full enterprise-quality undo/redo engine for the genesis monorepo, replacing the old `enterprise-undo` reference implementation.

## What was built

- Synchronous `UndoStack<T>` with memory limits, transactions, EventBus
- `BranchingHistory<T>` with fork-on-diverge
- `AsyncUndoStack<T>` for async commands
- `HistoryCompressor<T>` / `compressHistory` for memory management
- `SelectiveUndoStack<T>` for non-linear undo by command ID
- `CommandMerger<T>` with time/count windows
- Structured errors via `UNDO_CODES` (6 codes)
- Zod schemas, OTel instrumentation, property-based tests (fast-check)
- 100% istanbul coverage, all co-located `.md` docs