diff --git a/market_heatmap.go b/market_heatmap.go
index 8fb2944..94b5f2a 100644
--- a/market_heatmap.go
+++ b/market_heatmap.go
@@ -65,8 +65,8 @@ func MarketHeatmap(c *ui.Context, path *[]string, root HeatNode, opts MarketHeat
 			return k.Surface.Mix(trendColor(c, trendSign(ch)), float32(0.15+0.85*min(math.Abs(ch)/scale, 1)))
 		}
 		ch := newChart(c, opts.Frame)
-		spec := chartSpec{n: len(tiles)}
-		spec.readout = func(i int) string {
+		spec := ChartSpec{Marks: len(tiles)}
+		spec.Readout = func(i int) string {
 			t := tiles[i]
 			s := fmt.Sprintf("%s · %s %s%% · %s", t.name, trendWord(c, trendSign(t.change)), statisticSigned(t.change, 2), statisticFormat(t.cap, 0))
 			if t.branch {
@@ -74,7 +74,7 @@ func MarketHeatmap(c *ui.Context, path *[]string, root HeatNode, opts MarketHeat
 			}
 			return s
 		}
-		spec.pick = func(r ui.Rect, x, y float32) int {
+		spec.Pick = func(r ui.Rect, x, y float32) int {
 			for i, t := range squarify(caps, r) {
 				if t.Contains(x, y) {
 					return i
@@ -82,14 +82,14 @@ func MarketHeatmap(c *ui.Context, path *[]string, root HeatNode, opts MarketHeat
 			}
 			return -1
 		}
-		spec.activate = func(i int) {
+		spec.Activate = func(i int) {
 			if tiles[i].branch {
 				*path = append(slices.Clone(*path), tiles[i].name)
 				res.value = true
 				slog.Debug("mujica: market_heatmap drill", "path", strings.Join(*path, "/"))
 			}
 		}
-		spec.draw = func(p *ui.Painter, r ui.Rect, active int) {
+		spec.Draw = func(p *ui.Painter, r ui.Rect, active int) {
 			for i, t := range squarify(caps, r) {
 				bg := color(tiles[i].change)
 				p.Fill(t, bg, 2)
diff --git a/payoff_diagram.go b/payoff_diagram.go
index 17f59c1..5e4c224 100644
--- a/payoff_diagram.go
+++ b/payoff_diagram.go
@@ -126,18 +126,18 @@ func PayoffDiagram(c *ui.Context, legs []OptionLeg, opts PayoffDiagramOptions) C
 			internal.Linear{D0: ylo, D1: yhi, R0: float64(plot.Y + plot.H), R1: float64(plot.Y)}
 	}
 	up, down := trendColor(c, 1), trendColor(c, -1)
-	spec := chartSpec{n: n}
-	spec.readout = func(i int) string {
+	spec := ChartSpec{Marks: n}
+	spec.Readout = func(i int) string {
 		return fmt.Sprintf(msg(c, "payoff_diagram.readout"), format(d.px[i]), trendWord(c, trendSign(d.pl[i])), format(d.pl[i]))
 	}
-	spec.pick = func(r ui.Rect, x, y float32) int {
+	spec.Pick = func(r ui.Rect, x, y float32) int {
 		plot, xs, _ := geom(r)
 		if !plot.Contains(x, y) {
 			return -1
 		}
 		return max(0, min(n-1, int(math.Round((xs.Invert(x)-lo)/(hi-lo)*float64(n-1)))))
 	}
-	spec.draw = func(p *ui.Painter, r ui.Rect, active int) {
+	spec.Draw = func(p *ui.Painter, r ui.Rect, active int) {
 		plot, xs, ys := geom(r)
 		internal.AxisY(p, plot, ys, ticks, func(v float64) string { return internal.FormatTick(v, step) }, size, k)
 		lx, ll, lstep := internal.Nice(lo, hi, max(2, int(plot.W/90)))
diff --git a/performance_chart.go b/performance_chart.go
index 5ba745e..989933f 100644
--- a/performance_chart.go
+++ b/performance_chart.go
@@ -81,9 +81,9 @@ func PerformanceChart(c *ui.Context, values []float64, opts PerformanceChartOpti
 	if !ok {
 		n = 0
 	}
-	keys := make([]chartKey, len(series))
+	keys := make([]ChartLegendItem, len(series))
 	for i, s := range series {
-		keys[i] = chartKey{Name: s.Name, Color: pal[i], Shape: i}
+		keys[i] = ChartLegendItem{Name: s.Name, Color: pal[i], Shape: i}
 	}
 	var ticks []float64
 	var step float64
@@ -96,15 +96,15 @@ func PerformanceChart(c *ui.Context, values []float64, opts PerformanceChartOpti
 		plot := chartInset(r, 56, 26)
 		return plot, ax.scale(plot), internal.Linear{D0: lo, D1: hi, R0: float64(plot.Y + plot.H), R1: float64(plot.Y)}
 	}
-	spec := chartSpec{n: n, keys: keys, toggle: true}
-	spec.pick = func(r ui.Rect, x, y float32) int {
+	spec := ChartSpec{Marks: n, Legend: keys, Hidden: ch.toggles(true)}
+	spec.Pick = func(r ui.Rect, x, y float32) int {
 		plot, xs, _ := geom(r)
 		if !plot.Contains(x, y) {
 			return -1
 		}
 		return ax.nearest(xs.Invert(x))
 	}
-	spec.readout = func(i int) string {
+	spec.Readout = func(i int) string {
 		parts := []string{opts.Times[i].Format("2006-01-02")}
 		for _, s := range series {
 			if !ch.hidden(s.Name) {
@@ -113,7 +113,7 @@ func PerformanceChart(c *ui.Context, values []float64, opts PerformanceChartOpti
 		}
 		return strings.Join(parts, " · ")
 	}
-	spec.draw = func(p *ui.Painter, r ui.Rect, active int) {
+	spec.Draw = func(p *ui.Painter, r ui.Rect, active int) {
 		plot, xs, ys := geom(r)
 		x := func(i int) float32 { return internal.Snap(p, xs.Map(ax.vals[i])) }
 		if dd.Percent < 0 && !ch.hidden(name) {