tui: keep live output outside scrollback

internal/agent/modes/interactive.go

@@ -198,6 +198,7 @@ type Interactive struct {
 	toolOrder          []string
 	statusErr          string
 	statusOK           string
+	liveBlock          []string // live streaming/tool progress rendered outside scrollback
 	helpBlock          []string // rendered above the chat when /help was typed
 	cumUsage           provider.Usage
 	lastCtxInput       int // input_tokens of the most recent turn — approximates current context size
@@ -686,8 +687,21 @@ func (i *Interactive) buildChatLocked(cols int) []string {
 		}
 	}
 	i.view.Err = i.statusErr
+	i.liveBlock = i.view.BuildLive(cols)
 
+	streamingActive := i.view.StreamingActive
+	streaming := i.view.Streaming
+	toolCalls := i.view.ToolCalls
+	errLine := i.view.Err
+	i.view.StreamingActive = false
+	i.view.Streaming = ""
+	i.view.ToolCalls = nil
+	i.view.Err = ""
 	chat := i.view.Build(cols)
+	i.view.StreamingActive = streamingActive
+	i.view.Streaming = streaming
+	i.view.ToolCalls = toolCalls
+	i.view.Err = errLine
 
 	// Welcome banner: shown at the top of the chat area when there is
 	// no transcript yet. Disappears after the first message is sent.
@@ -950,7 +964,15 @@ func (i *Interactive) redraw() {
 	// content. The status block and editor get their own dedicated
 	// blanks so spacing stays consistent whether or not a dialog or
 	// popup is showing.
-	bottom := make([]string, 0, len(dialog)+len(suggest)+len(queue)+len(edLines)+8)
+	bottom := make([]string, 0, len(i.liveBlock)+len(dialog)+len(suggest)+len(queue)+len(edLines)+9)
+	if len(i.liveBlock) > 0 {
+		// Live streaming/tool rows are rendered outside the immutable
+		// transcript so native scrollback stays stable while the agent
+		// works. Add the same breathing row the finalized transcript path
+		// gets between adjacent messages.
+		bottom = append(bottom, "")
+		bottom = append(bottom, i.liveBlock...)
+	}
 	if len(dialog) > 0 {
 		bottom = append(bottom, "")
 	}
@@ -1079,23 +1101,29 @@ func (i *Interactive) redraw() {
 	// statusLines and edLines (input breathing room). Without
 	// these the rendered cursor would land on a blank instead of
 	// inside the editor row.
-	cursorRow := dialogLead + len(dialog) + len(suggest) + len(queue) + 1 + len(statusLines) + 1 + curR
+	liveRows := len(i.liveBlock)
+	if liveRows > 0 {
+		// Account for the leading separator row inserted before live
+		// streaming/tool content in the bottom block.
+		liveRows++
+	}
+	cursorRow := liveRows + dialogLead + len(dialog) + len(suggest) + len(queue) + 1 + len(statusLines) + 1 + curR
 	cursorCol := curC
 	if i.btwDialog.Active() {
 		if r, c := i.btwDialog.CursorPos(cols); r >= 0 {
-			cursorRow = dialogLead + r
+			cursorRow = liveRows + dialogLead + r
 			cursorCol = c
 		}
 	}
 	if i.dialog.Active() {
 		if r, c := i.dialog.CursorPos(cols); r >= 0 {
-			cursorRow = dialogLead + r
+			cursorRow = liveRows + dialogLead + r
 			cursorCol = c
 		}
 	}
 	if i.sessionDialog.Active() {
 		if r, c := i.sessionDialog.CursorPos(); r >= 0 {
-			cursorRow = dialogLead + r
+			cursorRow = liveRows + dialogLead + r
 			cursorCol = c
 		}
 	}

internal/tui/view.go

@@ -183,6 +183,47 @@ func (v *View) Build(width int) []string {
 	return lines
 }
 
+// BuildLive renders only in-flight assistant/tool/error state. Main-screen
+// scrollback renderers can keep these rows outside the immutable transcript
+// so native scrolling stays stable while a turn streams.
+func (v *View) BuildLive(width int) []string {
+	var out []string
+	if v.StreamingActive && strings.TrimSpace(v.Streaming) != "" {
+		const indent = "  "
+		inner := assistantBodyWidth(width - len(indent))
+		md := RenderMarkdown(v.Streaming, v.Theme, inner)
+		for _, l := range strings.Split(md, "\n") {
+			for _, w := range wrapANSILine(l, inner) {
+				out = append(out, indent+w)
+			}
+		}
+		out = append(out, "")
+	}
+	finalised := map[string]bool{}
+	for _, m := range v.Messages {
+		for _, c := range m.Content {
+			switch b := c.(type) {
+			case provider.ToolCallBlock:
+				finalised[b.ID] = true
+			case provider.ToolResultBlock:
+				finalised[b.CallID] = true
+			}
+		}
+	}
+	for _, tc := range v.ToolCalls {
+		if finalised[tc.ID] {
+			continue
+		}
+		out = append(out, v.renderToolCall(tc, width)...)
+		out = append(out, "")
+	}
+	if v.Err != "" {
+		out = append(out, v.Theme.FG256(v.Theme.Error, "✖ "+v.Err))
+		out = append(out, "")
+	}
+	return out
+}
+
 // BuildWithAnchors is like Build but additionally reports the first
 // row occupied by each message in v.Messages. Callers that need to
 // scroll to a specific turn (the /jump dialog) use the anchor slice
@@ -646,7 +687,7 @@ func (v *View) renderToolCall(tc ToolCallView, width int) []string {
 	if tc.Error {
 		color = v.Theme.Error
 	}
-	body := toolResultBlock(v.Theme, tc.Result, width, color)
+	body := toolResultBlock(v.Theme, tc.Result, toolBoxBodyRenderWidth(width), color)
 	for _, l := range v.collapseToolBody(body, false) {
 		imgCells, stripped := parseImageFootprint(l)
 		if hasImageEscapeLine(stripped) {
@@ -748,6 +789,7 @@ const toolBoxOuterMargin = 2
 // of the line so the right corner sits at column width-1, matching the
 // closing edge.
 func toolBoxTop(th Theme, label string, width int) string {
+	label = oneLineToolLabel(label)
 	w := width - 2*toolBoxOuterMargin
 	if w < 12 {
 		w = 12
@@ -782,6 +824,10 @@ func toolBoxTop(th Theme, label string, width int) string {
 	return margin + th.FG256(th.Muted, prefix) + th.FG256(th.FG, name) + th.FG256(th.Muted, rest+suffix+fillStr+"┐") + margin
 }
 
+func oneLineToolLabel(label string) string {
+	return strings.Join(strings.Fields(label), " ")
+}
+
 func splitToolLabel(label string) (name, rest string) {
 	label = strings.TrimLeft(label, " ")
 	if label == "" {
@@ -861,6 +907,25 @@ func parseImageFootprint(s string) (int, string) {
 // drifting too far right.
 const toolBoxBodyTrimLeft = 2
 
+// toolBoxBodyRenderWidth is the width body renderers should target before
+// their rows are wrapped by toolBoxSide. Most body renderers emit a four-cell
+// indent; toolBoxSide trims toolBoxBodyTrimLeft cells from that indent and
+// then adds the box edge/padding. Passing the full terminal width lets long
+// bash/heredoc lines overrun the inner box and makes terminals soft-wrap,
+// visually breaking the right edge. This returns the maximum renderer width
+// whose post-trim visible width fits inside the box.
+func toolBoxBodyRenderWidth(width int) int {
+	w := width - 2*toolBoxOuterMargin
+	if w < 12 {
+		w = 12
+	}
+	inner := w - 2 - 2*toolBoxInnerPad
+	if inner < 1 {
+		inner = 1
+	}
+	return inner + toolBoxBodyTrimLeft
+}
+
 // toolBoxSide wraps a single body line with vertical box edges:
 //
 //	│  foo bar baz                                            │
@@ -982,7 +1047,8 @@ func (v *View) renderToolResultContent(blocks []provider.Content, width, color i
 	for _, b := range blocks {
 		switch bb := b.(type) {
 		case provider.TextBlock:
-			body = append(body, v.renderToolText(bb.Text, width, color, sourcePath, startLine)...)
+			bodyWidth := toolBoxBodyRenderWidth(width)
+			body = append(body, v.renderToolText(bb.Text, bodyWidth, color, sourcePath, startLine)...)
 		case provider.ImageBlock:
 			hasImage = true
 			body = append(body, v.renderImageBlock(bb, width)...)
@@ -1399,7 +1465,9 @@ func (v *View) renderBashResult(lines []string, width, defaultColor int) []strin
 				out = append(out, "    "+v.Theme.FG256(v.Theme.Accent, w))
 			}
 		case i == footerIdx:
-			out = append(out, "    "+v.Theme.FG256(v.Theme.Muted, l))
+			for _, w := range wrapLine(l, width-4, "    ") {
+				out = append(out, "    "+v.Theme.FG256(v.Theme.Muted, w))
+			}
 		default:
 			for _, w := range wrapLine(l, width-4, "    ") {
 				out = append(out, "    "+v.Theme.FG256(defaultColor, w))
@@ -1586,7 +1654,7 @@ func ShortArgs(tool string, raw json.RawMessage) string {
 	x, ok := v.(map[string]any)
 	if !ok {
 		b, _ := json.Marshal(v)
-		s := string(b)
+		s := oneLineToolLabel(string(b))
 		if len(s) > 60 {
 			s = s[:57] + "..."
 		}
@@ -1601,12 +1669,13 @@ func ShortArgs(tool string, raw json.RawMessage) string {
 	}
 	if primary == "" {
 		b, _ := json.Marshal(v)
-		s := string(b)
+		s := oneLineToolLabel(string(b))
 		if len(s) > 60 {
 			s = s[:57] + "..."
 		}
 		return s
 	}
+	primary = oneLineToolLabel(primary)
 
 	// Tool-specific decoration. Only the read tool gets a range
 	// suffix for now; other tools just truncate the primary arg.