diff --git a/mention_input.go b/mention_input.go
index 88125c2..e286fb0 100644
--- a/mention_input.go
+++ b/mention_input.go
@@ -57,7 +57,7 @@ func MentionInput(c *ui.Context, value *string, mentions *[]Mention, opts Mentio
 	var r InputResult
 	look := &textInputLook{disabled: opts.Disabled, err: opts.Error}
 	r.Element, r.Input = textInputFrame(c, look, func(frame *ui.Element) *ui.Element {
-		in := ui.Box(c).Grow(1).MinWidth(Density(c).Unit()*20).Focusable().Clip().Role(ui.RoleTextField).Label(opts.Label).Cursor(ui.CursorText)
+		in := ui.Box(c).Grow(1).MinWidth(Density(c).Unit() * 20).Focusable().Clip().Role(ui.RoleTextField).Label(opts.Label).Cursor(ui.CursorText)
 		s := *ui.Local(in, "mention_input", func() *mentionInputState { return &mentionInputState{at: -1} })
 		if s.doc.text == nil || s.synced != *value || !slices.Equal(s.syncedMentions, *mentions) {
 			// Set from outside: start over at the end.
@@ -314,7 +314,9 @@ func mentionInputPopup(c *ui.Context, k theme.Tokens, s *mentionInputState, fram
 						Radius(theme.ControlRadius).Role(ui.RoleListItem).Label(m.Name).Cursor(ui.CursorPointer)
 					if i == s.pick {
 						it.Selected(true).Background(k.Selection).TextColor(k.AccentText)
-						it.Draw(func(p *ui.Painter, r ui.Rect) { p.Fill(ui.Rect{X: r.X, Y: r.Y + 6, W: 2, H: r.H - 12}, k.AccentText, 0) })
+						it.Draw(func(p *ui.Painter, r ui.Rect) {
+							p.Fill(ui.Rect{X: r.X, Y: r.Y + 6, W: 2, H: r.H - 12}, k.AccentText, 0)
+						})
 					} else if it.Hovered() {
 						it.Background(k.SurfaceHover)
 					}
diff --git a/messages_essentials.go b/messages_essentials.go
index fcb62b3..ad95e04 100644
--- a/messages_essentials.go
+++ b/messages_essentials.go
@@ -21,6 +21,11 @@ func init() {
 		"currency_input.invalid":   {"Enter an amount, such as 1,234.50", "请输入金额，例如 1,234.50"},
 		"currency_input.precision": {"Use at most %d decimal places", "最多保留 %d 位小数"},
 
+		"signature_pad.label": {"Signature", "签名"},
+		"signature_pad.hint":  {"Draw with the pointer; Delete clears", "用鼠标书写；Delete 键清除"},
+		"signature_pad.empty": {"Sign here", "请在此签名"},
+		"signature_pad.clear": {"Clear", "清除"},
+
 		"qr_code.label":    {"QR code", "二维码"},
 		"qr_code.too_long": {"Text too long for a QR code", "文字过长，无法生成二维码"},
 	})
diff --git a/signature_pad.go b/signature_pad.go
new file mode 100644
index 0000000..53352b8
--- /dev/null
+++ b/signature_pad.go
@@ -0,0 +1,153 @@
+package mujica
+
+import (
+	"cmp"
+	"log/slog"
+	"math"
+	"strconv"
+	"strings"
+
+	"github.com/egoist/mygo/ui"
+
+	"mujicaui/icons"
+	"mujicaui/internal"
+	"mujicaui/theme"
+)
+
+// SignaturePoint is a point of a stroke, in DIPs from the pad's top left.
+type SignaturePoint struct{ X, Y float32 }
+
+// SignaturePadOptions configure a SignaturePad.
+type SignaturePadOptions struct {
+	// Height is the drawing area's height; zero is 160. The pad fills its parent's width.
+	Height float32
+	// Label names the pad; empty uses "Signature".
+	Label    string
+	Disabled bool
+}
+
+// SignaturePath writes strokes as SVG path data: "M x y L x y …" per stroke.
+func SignaturePath(strokes [][]SignaturePoint) string {
+	var b strings.Builder
+	num := func(v float32) string { return strconv.FormatFloat(float64(v), 'f', -1, 32) }
+	for _, st := range strokes {
+		for i, p := range st {
+			if b.Len() > 0 {
+				b.WriteByte(' ')
+			}
+			if i == 0 {
+				b.WriteString("M ")
+			} else {
+				b.WriteString("L ")
+			}
+			b.WriteString(num(p.X) + " " + num(p.Y))
+		}
+	}
+	return b.String()
+}
+
+// signaturePadDrawing is the stroke in progress.
+type signaturePadDrawing struct {
+	active, ended bool
+}
+
+// SignaturePad records pointer strokes into *strokes; Changed reports a finished stroke or a clear.
+func SignaturePad(c *ui.Context, strokes *[][]SignaturePoint, opts SignaturePadOptions) ChoiceResult {
+	if strokes == nil {
+		panic("mujica: SignaturePad needs strokes")
+	}
+	if !(opts.Height >= 0) || math.IsInf(float64(opts.Height), 1) {
+		panic("mujica: SignaturePad Height must be finite and >= 0")
+	}
+	k := Tokens(c)
+	u := Density(c).Unit()
+	name := cmp.Or(opts.Label, msg(c, "signature_pad.label"))
+	col := ui.Column(c).FillWidth().Gap(u * 2).Disabled(opts.Disabled)
+	disabled := col.IsDisabled()
+	changed := false
+	col.Children(func() {
+		pad := ui.Box(c).FillWidth().Height(cmp.Or(opts.Height, 160)).Focusable().Radius(theme.CardRadius).Clip().
+			Background(k.Surface).Border(theme.BorderWidth, k.ControlBorder).Cursor(ui.CursorCrosshair).
+			Role(ui.RoleImage).Label(name).Description(msg(c, "signature_pad.hint"))
+		internal.Ring(pad, k.Focus, theme.CardRadius)
+		d := ui.Local(pad, "signature_pad", func() *signaturePadDrawing { return &signaturePadDrawing{} })
+		s := *d
+		pad.HandleInput(func(ev ui.InputEvent) bool {
+			if pad.IsDisabled() {
+				return false
+			}
+			pt := SignaturePoint{ev.X, ev.Y}
+			switch {
+			case ev.Kind == ui.InputPointerDown && ev.Button == 0:
+				*strokes = append(*strokes, []SignaturePoint{pt})
+				s.active = true
+				pad.Focus()
+			case ev.Kind == ui.InputPointerMove && s.active && len(*strokes) > 0:
+				last := &(*strokes)[len(*strokes)-1]
+				if q := (*last)[len(*last)-1]; math.Hypot(float64(pt.X-q.X), float64(pt.Y-q.Y)) >= 1 {
+					*last = append(*last, pt)
+				}
+			case ev.Kind == ui.InputPointerUp && s.active:
+				s.active, s.ended = false, true
+			default:
+				return false
+			}
+			return true
+		})
+		if s.ended {
+			s.ended, changed = false, true
+			slog.Debug("mujica: signature_pad stroke", "strokes", len(*strokes))
+		}
+		clear := func() {
+			if len(*strokes) > 0 {
+				*strokes, changed = nil, true
+				slog.Debug("mujica: signature_pad clear")
+			}
+		}
+		if !disabled && (pad.Shortcut(0, ui.KeyDelete) || pad.Shortcut(0, ui.KeyBackspace)) {
+			clear()
+		}
+		ink := signaturePadClone(*strokes)
+		empty := len(ink) == 0
+		size := FontSize(c, theme.CaptionSize)
+		pad.Draw(func(p *ui.Painter, r ui.Rect) {
+			line := r.Y + r.H - 28
+			internal.Rule(p, r.X+16, r.X+r.W-16, line, k.Border)
+			p.Text(r.X+16, line+4, "×", size, k.TextMuted)
+			if empty {
+				w, _ := p.MeasureText(0, ui.Span{Text: msg(c, "signature_pad.empty"), Size: size})
+				p.Text(r.X+(r.W-w)/2, r.Y+r.H/2-size, msg(c, "signature_pad.empty"), size, k.TextMuted)
+			}
+			for _, st := range ink {
+				var path ui.Path
+				for i, q := range st {
+					x, y := internal.Snap(p, r.X+q.X), internal.Snap(p, r.Y+q.Y)
+					if i == 0 {
+						path.MoveTo(x, y)
+					} else {
+						path.LineTo(x, y)
+					}
+				}
+				if len(st) == 1 {
+					path.Circle(internal.Snap(p, r.X+st[0].X), internal.Snap(p, r.Y+st[0].Y), 1)
+				}
+				p.StrokePath(&path, 2, k.Text)
+			}
+		})
+		ui.Row(c).Children(func() {
+			if Button(c, msg(c, "signature_pad.clear"), ButtonOptions{Variant: Ghost, Icon: icons.Must("trash-2"), Disabled: empty}).Clicked() && !disabled {
+				clear()
+			}
+		})
+	})
+	return ChoiceResult{col, changed}
+}
+
+// signaturePadClone copies strokes so painting never sees later edits.
+func signaturePadClone(s [][]SignaturePoint) [][]SignaturePoint {
+	out := make([][]SignaturePoint, len(s))
+	for i, st := range s {
+		out[i] = append([]SignaturePoint(nil), st...)
+	}
+	return out
+}
diff --git a/signature_pad_test.go b/signature_pad_test.go
new file mode 100644
index 0000000..5aaf1c8
--- /dev/null
+++ b/signature_pad_test.go
@@ -0,0 +1,72 @@
+package mujica
+
+import (
+	"testing"
+
+	"github.com/egoist/mygo/ui"
+)
+
+func TestSignaturePath(t *testing.T) {
+	got := SignaturePath([][]SignaturePoint{{{1, 2}, {3.5, 4}}, {{10, 10}}})
+	if want := "M 1 2 L 3.5 4 M 10 10"; got != want {
+		t.Fatalf("path %q, want %q", got, want)
+	}
+	if SignaturePath(nil) != "" {
+		t.Fatal("empty strokes made a path")
+	}
+}
+
+func TestSignaturePadStrokesAndClear(t *testing.T) {
+	var strokes [][]SignaturePoint
+	dis := false
+	n := 0
+	tt := ui.NewTester(func(c *ui.Context) {
+		Use(c, Settings{})
+		ui.Column(c).Padding(20).Width(400).Children(func() {
+			if SignaturePad(c, &strokes, SignaturePadOptions{Disabled: dis}).Changed() {
+				n++
+			}
+		})
+	}, 500, 300)
+	tt.Press(50, 60)
+	tt.Move(80, 70)
+	tt.Move(80.5, 70) // under a DIP: not kept
+	tt.Move(120, 90)
+	tt.Release(120, 90)
+	if len(strokes) != 1 || len(strokes[0]) != 3 || strokes[0][0] != (SignaturePoint{30, 40}) || n != 1 {
+		t.Fatalf("stroke %+v, changes %d", strokes, n)
+	}
+	tt.Press(200, 60)
+	tt.Release(200, 60)
+	if len(strokes) != 2 || n != 2 {
+		t.Fatalf("dot: %+v", strokes)
+	}
+	tt.Key(0, ui.KeyDelete) // drawing focused the pad
+	if len(strokes) != 0 || n != 3 {
+		t.Fatalf("Delete kept %d strokes", len(strokes))
+	}
+	tt.Press(50, 60)
+	tt.Release(50, 60)
+	if err := tt.Click("Clear"); err != nil || len(strokes) != 0 {
+		t.Fatalf("Clear button: %v %d", err, len(strokes))
+	}
+	dis = true
+	tt.Frame()
+	tt.Press(50, 60)
+	tt.Move(90, 60)
+	tt.Release(90, 60)
+	if len(strokes) != 0 {
+		t.Fatal("disabled pad drew")
+	}
+}
+
+func TestSignaturePadSnapshot(t *testing.T) {
+	strokes := [][]SignaturePoint{{{30, 90}, {50, 60}, {60, 95}, {80, 55}, {95, 100}, {120, 70}, {150, 85}}, {{170, 60}, {175, 100}}}
+	var empty [][]SignaturePoint
+	snapshot(t, "signature_pad", 560, 260, func(c *ui.Context) {
+		ui.Row(c).Padding(16).Gap(16).Children(func() {
+			ui.Column(c).Width(250).Children(func() { SignaturePad(c, &strokes, SignaturePadOptions{Height: 180}) })
+			ui.Column(c).Width(250).Children(func() { SignaturePad(c, &empty, SignaturePadOptions{Height: 180}) })
+		})
+	})
+}
diff --git a/testdata/snapshots/darwin/signature_pad-dark.png b/testdata/snapshots/darwin/signature_pad-dark.png
new file mode 100644
index 0000000..aec2569
Binary files /dev/null and b/testdata/snapshots/darwin/signature_pad-dark.png differ
diff --git a/testdata/snapshots/darwin/signature_pad-light.png b/testdata/snapshots/darwin/signature_pad-light.png
new file mode 100644
index 0000000..ac20d18
Binary files /dev/null and b/testdata/snapshots/darwin/signature_pad-light.png differ