Undo tree

Vim Motions tracks branching undo history in a shadow tree parallel to CM6’s linear undo stacks. When you undo and make a new edit, the old “future” becomes an alternative branch — accessible via g-/g+ or :earlier/:later. Inspired by Neovim’s undotree.

Navigation

Chronological (g-/g+)

g- moves to the chronologically older state across ALL branches. g+ moves to the chronologically newer state. The buffer content changes — you see the document revert or advance.

Unlike u/Ctrl-R which only navigate the current branch, g-/g+ traverse every state in the order it was created, regardless of which branch it’s on.

By count (:earlier/:later)

Command	Effect
:earlier N	Go back N changes
:later N	Go forward N changes
:earlier Ns	Go to state from N seconds ago
:earlier Nm	Go to state from N minutes ago
:earlier Nh	Go to state from N hours ago
:earlier Nd	Go to state from N days ago
:earlier Nf	Go to Nth previous save point
:later Nf	Go to Nth next save point

Undo list (:undolist)

:undolist opens a modal showing all undo tree nodes with their sequence number, timestamp, change summary, save status, and branch count. The current node is marked with >.

Sidebar view

:UndoTreeToggle (or :UndoTreeShow/:UndoTreeHide) opens a sidebar panel showing the undo tree as a visual hierarchy.

Keyboard navigation

Key	Action
j	Select next node
k	Select previous node
Enter	Navigate to selected node
q	Close sidebar

Click any node to navigate to it.

Neovim RPC ownership

With the Neovim RPC backend connected, u, <C-r>, g-, g+, :undolist, :earlier, and :later run natively in Neovim. :UndoTreeToggle, :UndoTreeShow, and :UndoTreeHide remain host commands because they manage an Obsidian workspace leaf. The sidebar fetches Neovim’s vim.fn.undotree() result instead of displaying CM6’s shadow history.

Features

• Relative timestamps — “3m ago”, “1h ago”
• Change summary — “+7 chars, -3 chars”
• Branch indicators — shows when a node has multiple children
• Collapse/expand — click the toggle to collapse alternate branches
• Current node highlight — the active state is visually distinct
• Saved markers — nodes where the file was saved are flagged

Lua API

vim.fn.undotree() returns a Neovim-compatible dictionary:

local tree = vim.fn.undotree()
print(tree.seq_last)   -- highest sequence number
print(tree.seq_cur)    -- current position
print(tree.time_cur)   -- timestamp of current state (Unix seconds)
print(#tree.entries)   -- number of entries on the main branch

Settings

Configure via Settings → Vim Motions → Undo tree or vimrc/Lua:

Setting	Default	Description
enableUndoTree	true	Enable undo tree tracking
undoTreeMaxNodes	1000	Maximum nodes per file (oldest branches pruned)
undoTreePosition	right	Sidebar position (left/right)
undoTreeAutoOpen	false	Auto-open sidebar on branch creation
undoFile	false	Persist undo tree across sessions

Memory management

Undo trees are automatically evicted from memory when all editors for a file are closed. When undoFile is enabled, dirty trees are persisted before eviction. Reopening a file restores from persistence or starts fresh.

External modification detection

When undoFile is enabled and a file was modified outside Obsidian between sessions, a notification is shown indicating the undo tree is stale. The tree structure is preserved for :undolist display, but navigation is disabled for that session.

Vimrc

set undotree          " enable (default)
set noundotree        " disable
set undofile          " persist across sessions
set noundofile        " session-only (default)

Lua

vim.opt.undotree = true
vim.opt.undofile = true
vim.opt.undotreemaxnodes = 500