feat: multi-cursor editing

README.md

@@ -67,6 +67,7 @@ cp bin/ttt ~/.local/bin/
 - **Undo/redo** (Ctrl+Z/Y) via a command-pattern undo stack
 - **`.editorconfig` support** — indent size is picked up automatically per file
 - **Indent detection** — auto-detects indentation from file content; manual override via the status bar indent picker
+- **Multi-cursor editing** — Ctrl+D to select next occurrence, Ctrl+K L to select all occurrences, Alt+Click to add cursors; typing, backspace, delete, and enter work at all positions simultaneously
 - **Mouse support** — click to position cursor, click tabs, drag sidebar/panel dividers, right-click context menus
 - **Auto-completion** — LSP-powered completions with live filtering, debounce, and auto-import support
 - **Signature help** — parameter hints shown automatically on `(` and `,`
@@ -412,6 +413,12 @@ All keybindings are customizable via `keybindings.json`. Supports chord sequence
 | Ctrl+X | Cut |
 | Ctrl+V | Paste |
 | Ctrl+G | Go to line |
+| | **Multi-Cursor** |
+| Ctrl+D | Select next occurrence |
+| Ctrl+K L | Select all occurrences |
+| Alt+Click | Add cursor at click position |
+| Ctrl+K U | Undo last cursor addition |
+| Escape | Collapse to single cursor |
 | | **Search** |
 | Ctrl+F | Find |
 | Ctrl+H | Find and replace |

cmd/ttt/commands.go

@@ -200,6 +200,10 @@ func registerEditorCommands(reg *command.Registry, app *App, running *bool, quit
 				app.DismissAutocomplete()
 				return
 			}
+			if app.editorGroup.IsMultiCursorActive() {
+				app.editorGroup.CollapseMultiCursor()
+				return
+			}
 			app.FocusEditor()
 		},
 	})
@@ -521,6 +525,19 @@ func registerEditorCommands(reg *command.Registry, app *App, running *bool, quit
 		Handler: func() { app.editorGroup.DeleteWordRight() },
 	})
 
+	reg.Register(command.Command{
+		ID: "multicursor.selectNext", Title: "Add Next Occurrence",
+		Handler: func() { app.editorGroup.SelectNextOccurrence() },
+	})
+	reg.Register(command.Command{
+		ID: "multicursor.selectAll", Title: "Select All Occurrences",
+		Handler: func() { app.editorGroup.SelectAllOccurrences() },
+	})
+	reg.Register(command.Command{
+		ID: "multicursor.undoCursor", Title: "Undo Last Cursor",
+		Handler: func() { app.editorGroup.UndoLastCursor() },
+	})
+
 	reg.Register(command.Command{
 		ID: "editor.quit", Title: "Quit",
 		Handler: func() {

cmd/ttt/eventloop.go

@@ -37,6 +37,7 @@ func runEventLoop(
 		app.status.Line = line
 		app.status.Col = col
 		app.status.Dirty = app.editorGroup.IsDirty()
+		app.status.CursorCount = app.editorGroup.MultiCursorCount()
 		app.explorer.ActiveFile = filePath
 
 		if app.editorGroup.Editor != nil && app.editorGroup.Editor.Highlighter != nil {

cmd/ttt/menus.go

@@ -39,6 +39,10 @@ var menuBarMenus = [][]ui.ContextMenuItem{
 	// Selection
 	{
 		{Label: "Select All", Command: "editor.selectAll"},
+		ui.MenuSep(),
+		{Label: "Add Next Occurrence", Command: "multicursor.selectNext"},
+		{Label: "Select All Occurrences", Command: "multicursor.selectAll"},
+		{Label: "Undo Last Cursor", Command: "multicursor.undoCursor"},
 	},
 	// View
 	{

docs-web/src/content/docs/getting-started/introduction.md

@@ -11,6 +11,7 @@ TTT (Terminal Text Tool) is a fully-featured code editor that runs in your termi
 
 - **Single binary** built with Go, no runtime dependencies
 - **Zero config** out of the box, but fully customizable
+- **Multi-cursor editing** with Ctrl+D, Ctrl+K L, and Alt+Click
 - **LSP support** for language-aware editing (completions, diagnostics, formatting, rename, references)
 - **Integrated terminal** with full VT escape sequence support
 - **Git integration** with staging, committing, and diff view

docs-web/src/content/docs/getting-started/quick-start.md

@@ -30,6 +30,8 @@ ttt --workspace project.ttt     # loads a saved workspace file
 - **Ctrl+C / Ctrl+X / Ctrl+V** for copy/cut/paste
 - **Ctrl+F** to find, **Ctrl+H** to find and replace
 - **Ctrl+A** to select all
+- **Ctrl+D** to select the next occurrence (multi-cursor)
+- **Alt+Click** to add cursors at multiple positions
 
 ## Tabs
 

docs-web/src/content/docs/guides/editor.md

@@ -31,6 +31,28 @@ Press **Ctrl+G** to open the Go to Line dialog.
 - **Ctrl+Z** to undo, **Ctrl+Y** to redo
 - Uses a command-pattern undo stack for reliable history tracking
 
+## Multi-Cursor Editing
+
+TTT supports editing with multiple cursors simultaneously. Place cursors at multiple locations and type, delete, or insert lines — all cursors act in parallel.
+
+### Adding Cursors
+
+- **Ctrl+D** — select the current word (or extend the current selection) and add a cursor at the next occurrence
+- **Ctrl+K L** — select all occurrences of the current word/selection at once
+- **Alt+Click** — add a cursor at the clicked position
+
+### Removing Cursors
+
+- **Ctrl+K U** — undo the last cursor addition
+- **Escape** — collapse back to a single cursor (when multiple cursors are active)
+
+### Behavior
+
+- Typing, backspace, delete, and enter work at all cursor positions simultaneously
+- Undo/redo groups multi-cursor edits into a single action
+- The status bar shows the cursor count (e.g., "3 cursors") when multiple cursors are active
+- All cursors render as solid blocks
+
 ## Indentation
 
 TTT supports `.editorconfig` files and picks up indent size automatically per file. It also auto-detects indentation from file content. You can manually override indentation via the status bar indent picker.

docs-web/src/content/docs/guides/keybindings.md

@@ -36,6 +36,16 @@ All keybindings are customizable via `keybindings.json`. TTT supports chord sequ
 | Ctrl+V | Paste |
 | Ctrl+G | Go to line |
 
+### Multi-Cursor
+
+| Shortcut | Action |
+|----------|--------|
+| Ctrl+D | Select next occurrence |
+| Ctrl+K L | Select all occurrences |
+| Alt+Click | Add cursor at click position |
+| Ctrl+K U | Undo last cursor addition |
+| Escape | Collapse to single cursor |
+
 ### Search
 
 | Shortcut | Action |

docs-web/src/content/docs/index.mdx

@@ -33,6 +33,9 @@ import { Card, CardGrid } from '@astrojs/starlight/components';
   <Card title="Multi-Folder Workspaces" icon="open-book">
     Open multiple project directories in a single session with per-folder git status and search.
   </Card>
+  <Card title="Multi-Cursor Editing" icon="pencil">
+    Place cursors at multiple locations with Ctrl+D, Ctrl+K L, or Alt+Click. Type, delete, and insert at all positions simultaneously.
+  </Card>
   <Card title="Theming" icon="star">
     10 built-in themes with full customization. Every color in the editor is configurable via JSON.
   </Card>

docs-web/src/content/docs/reference/keybindings.md

@@ -45,6 +45,16 @@ All keybindings can be customized in `~/.config/ttt/keybindings.json`.
 | Alt+Delete | `editor.deleteWordRight` | Delete word right |
 | Ctrl+Delete | `editor.deleteWordRight` | Delete word right |
 
+## Multi-Cursor
+
+| Shortcut | Command | Description |
+|----------|---------|-------------|
+| Ctrl+D | `editor.selectNextOccurrence` | Select next occurrence of current word/selection |
+| Ctrl+K L | `editor.selectAllOccurrences` | Select all occurrences at once |
+| Alt+Click | *(mouse)* | Add cursor at click position |
+| Ctrl+K U | `editor.undoCursor` | Undo last cursor addition |
+| Escape | `editor.focus` | Collapse to single cursor (when multiple cursors exist) |
+
 ## Search
 
 | Shortcut | Command | Description |

internal/config/keybindings.go

@@ -174,6 +174,9 @@ func DefaultKeybindings() []KeyBinding {
 		{Key: "ctrl+l x", Command: "editor.fixAll"},
 		{Key: "ctrl+l r", Command: "editor.findReferences"},
 		{Key: "ctrl+l t", Command: "editor.goToTypeDefinition"},
+		{Key: "ctrl+d", Command: "multicursor.selectNext"},
+		{Key: "ctrl+k l", Command: "multicursor.selectAll"},
+		{Key: "ctrl+k u", Command: "multicursor.undoCursor"},
 		{Key: "alt+up", Command: "editor.moveLineUp"},
 		{Key: "alt+down", Command: "editor.moveLineDown"},
 		{Key: "alt+shift+up", Command: "editor.duplicateLine"},

internal/core/multicursor/multicursor.go

@@ -0,0 +1,133 @@
+package multicursor
+
+import (
+	"sort"
+
+	"github.com/eugenioenko/ttt/internal/core/selection"
+)
+
+type CursorState struct {
+	Line, Col, Goal int
+	Sel             selection.Selection
+}
+
+type MultiCursor struct {
+	Cursors []CursorState
+	Primary int
+	history []CursorState
+}
+
+func New(line, col int) *MultiCursor {
+	return &MultiCursor{
+		Cursors: []CursorState{{Line: line, Col: col}},
+		Primary: 0,
+	}
+}
+
+func (mc *MultiCursor) IsMulti() bool {
+	return len(mc.Cursors) > 1
+}
+
+func (mc *MultiCursor) PrimaryCursor() CursorState {
+	if mc.Primary >= 0 && mc.Primary < len(mc.Cursors) {
+		return mc.Cursors[mc.Primary]
+	}
+	return CursorState{}
+}
+
+func (mc *MultiCursor) Add(line, col int) {
+	for _, c := range mc.Cursors {
+		if c.Line == line && c.Col == col {
+			return
+		}
+	}
+	cs := CursorState{Line: line, Col: col}
+	mc.history = append(mc.history, cs)
+	mc.Cursors = append(mc.Cursors, cs)
+	mc.Sort()
+}
+
+func (mc *MultiCursor) AddWithSelection(line, col int, sel selection.Selection) {
+	for _, c := range mc.Cursors {
+		if c.Line == line && c.Col == col {
+			return
+		}
+	}
+	cs := CursorState{Line: line, Col: col, Sel: sel}
+	mc.history = append(mc.history, cs)
+	mc.Cursors = append(mc.Cursors, cs)
+	mc.Sort()
+}
+
+func (mc *MultiCursor) RemoveLast() (CursorState, bool) {
+	if len(mc.history) == 0 || len(mc.Cursors) <= 1 {
+		return CursorState{}, false
+	}
+	last := mc.history[len(mc.history)-1]
+	mc.history = mc.history[:len(mc.history)-1]
+	for i, c := range mc.Cursors {
+		if c.Line == last.Line && c.Col == last.Col {
+			mc.Cursors = append(mc.Cursors[:i], mc.Cursors[i+1:]...)
+			if mc.Primary >= len(mc.Cursors) {
+				mc.Primary = len(mc.Cursors) - 1
+			}
+			return last, true
+		}
+	}
+	return last, false
+}
+
+func (mc *MultiCursor) CollapseToSingle() {
+	if len(mc.Cursors) == 0 {
+		return
+	}
+	primary := mc.PrimaryCursor()
+	primary.Sel.Clear()
+	mc.Cursors = []CursorState{primary}
+	mc.Primary = 0
+	mc.history = nil
+}
+
+func (mc *MultiCursor) Sort() {
+	if mc.Primary < 0 || mc.Primary >= len(mc.Cursors) {
+		mc.Primary = 0
+		return
+	}
+	p := mc.Cursors[mc.Primary]
+	sort.SliceStable(mc.Cursors, func(i, j int) bool {
+		a, b := mc.Cursors[i], mc.Cursors[j]
+		if a.Line != b.Line {
+			return a.Line < b.Line
+		}
+		return a.Col < b.Col
+	})
+	for i, c := range mc.Cursors {
+		if c.Line == p.Line && c.Col == p.Col {
+			mc.Primary = i
+			break
+		}
+	}
+}
+
+func (mc *MultiCursor) Deduplicate() {
+	if len(mc.Cursors) <= 1 {
+		return
+	}
+	mc.Sort()
+	p := mc.Cursors[mc.Primary]
+	unique := mc.Cursors[:1]
+	for i := 1; i < len(mc.Cursors); i++ {
+		prev := unique[len(unique)-1]
+		if mc.Cursors[i].Line != prev.Line || mc.Cursors[i].Col != prev.Col {
+			unique = append(unique, mc.Cursors[i])
+		}
+	}
+	mc.Cursors = unique
+	mc.Primary = 0
+	for i, c := range mc.Cursors {
+		if c.Line == p.Line && c.Col == p.Col {
+			mc.Primary = i
+			break
+		}
+	}
+}