feat(tui): add flat (boxless) tool-render mode

Tool calls render inside a bordered panel by default. On screens with
many calls the borders read as busy, so add an opt-in flat mode: a
quiet header line per call plus indented, border-free output. Tool
name, arg summary, streamed live output, theme colors, and the
ctrl+o truncation/expand behaviour are all preserved.

Gated behind a non-breaking toggle (default stays box):

  - config.json "tool_render": "box" | "flat"
  - ZOT_FLAT_TOOLS env var overrides the config for a single run

Purely a TUI-layer change; core and agent are untouched.

README.md

@@ -555,6 +555,38 @@ When a tool returns an image (for example `read` on a PNG), zot renders it inlin
 
 Frames containing images are full-repainted (no differential diff) to prevent stale image pixels from lingering through scroll. That costs one terminal flash per image-containing frame; set `ZOT_INLINE_IMAGES=off` if that bothers you.
 
+## Tool rendering
+
+By default each tool call (bash, read, write, edit) renders inside a bordered panel — a `┌─ header ─┐`, `│`-prefixed body rows, and a `└─┘` footer. On a screen with many calls the borders can read as busy, so zot also offers a **flat** mode: a single quiet header line per call (`▌ bash …`) with indented, border-free output. Same information — tool name, arg summary, streamed output, the `... (N more lines, ctrl+o to expand)` truncation — just no frame.
+
+Set the `tool_render` key in `$ZOT_HOME/config.json`:
+
+```json
+{
+  "tool_render": "flat"
+}
+```
+
+| Value | Effect |
+|---|---|
+| unset / `"box"` (default) | Each tool call is wrapped in a bordered panel. |
+| `"flat"` | Boxless: a quiet header line plus indented output. |
+
+The `ZOT_FLAT_TOOLS` env var overrides the config for a single run, which is handy for trying it without editing the file:
+
+| Value | Effect |
+|---|---|
+| `1`, `true`, `yes`, `on`, `flat` | Force flat rendering. |
+| `0`, `false`, `no`, `off`, `box` | Force the bordered panel. |
+| unset | Fall back to the `tool_render` config key. |
+
+```sh
+ZOT_FLAT_TOOLS=1 zot   # flat, just this run
+ZOT_FLAT_TOOLS=0 zot   # boxes, even if config.json says "flat"
+```
+
+Either way, theme colors still drive the rendering (the header uses your accent/foreground, output uses the tool-output color) and `ctrl+o` still expands a truncated result.
+
 ## Queued messages
 
 You can keep typing while the agent is working. Pressing `enter` during a turn queues the message instead of interrupting: it shows up above the status bar as `sliding in: <text>` and is delivered as the next user turn the moment the current one finishes. Queue as many as you want; they run in order. `esc` cancels the active turn and drops the queue so a runaway turn doesn't flood you with stale follow-ups; `ctrl+c` while busy arms the exit hint instead of interrupting, a second `ctrl+c` within two seconds exits zot.

packages/agent/cli.go

@@ -966,6 +966,7 @@ func runInteractive(ctx context.Context, args Args, version string) error {
 		RecursiveFileSuggest:       initialCfg.RecursiveFileSuggest,
 		RespectGitignore:           initialCfg.RespectGitignore,
 		ThemeName:                  initialCfg.Theme,
+		FlatTools:                  initialCfg.FlatToolRender(),
 		ExtensionThemes:            extMgr.ThemeOptions,
 		AutoSwarmSystemAddendum:    AutoSwarmSystemAddendum,
 		SettingsStore:              configSettingsStore{},

packages/agent/config.go

@@ -29,6 +29,13 @@ type Config struct {
 	Temperature *float32 `json:"temperature,omitempty"`
 	Theme       string   `json:"theme"`
 
+	// ToolRender selects how tool calls are drawn in interactive mode.
+	// "box" (default, or empty) wraps each call in a bordered panel;
+	// "flat" drops the frame for a quiet header line plus indented,
+	// frameless output. The ZOT_FLAT_TOOLS env var overrides this when
+	// set ("1"/"true" forces flat, "0"/"false" forces box).
+	ToolRender string `json:"tool_render,omitempty"`
+
 	// QuickModelShortcuts maps slots 1-9 to provider/model pairs used by
 	// Ctrl+1..9. Cmd+1..9 may also work on terminals that forward Super.
 	QuickModelShortcuts []QuickModelShortcut `json:"quick_model_shortcuts,omitempty"`
@@ -97,6 +104,23 @@ func ZotHome() string {
 // ConfigPath returns the path to config.json.
 func ConfigPath() string { return filepath.Join(ZotHome(), "config.json") }
 
+// FlatToolRender reports whether tool calls should render flat (no
+// bordered panel). The ZOT_FLAT_TOOLS env var takes precedence over
+// the config when set: "1"/"true"/"yes"/"on" force flat, "0"/"false"/
+// "no"/"off" force box. Otherwise the config's tool_render is
+// consulted; "flat" is flat, anything else (including empty) is box.
+func (c Config) FlatToolRender() bool {
+	if v := strings.TrimSpace(strings.ToLower(os.Getenv("ZOT_FLAT_TOOLS"))); v != "" {
+		switch v {
+		case "1", "true", "yes", "on", "flat":
+			return true
+		case "0", "false", "no", "off", "box":
+			return false
+		}
+	}
+	return strings.EqualFold(strings.TrimSpace(c.ToolRender), "flat")
+}
+
 // AuthPath returns the path to auth.json.
 func AuthPath() string { return filepath.Join(ZotHome(), "auth.json") }
 

packages/agent/modes/interactive.go

@@ -61,6 +61,11 @@ type InteractiveConfig struct {
 	// ThemeName mirrors the persisted config theme value. Empty means auto.
 	ThemeName string
 
+	// FlatTools renders tool calls without the bordered panel (a quiet
+	// header line plus indented, frameless output). Mirrors the
+	// resolved tool_render config / ZOT_FLAT_TOOLS env at startup.
+	FlatTools bool
+
 	// QuickModelShortcuts maps slots 1-9 to provider/model pairs. The
 	// shortcuts are Ctrl+1..9. Cmd+1..9 may also work when the terminal
 	// forwards Command/Super keypresses, but Ctrl is the displayed chord.
@@ -475,6 +480,7 @@ func NewInteractive(cfg InteractiveConfig) *Interactive {
 		view: &tui.View{
 			Theme:      cfg.Theme,
 			ImageProto: effectiveImageProtocol(cfg.InlineImagesEnabled),
+			FlatTools:  cfg.FlatTools,
 		},
 		// Prompt is the standard half-block accent bar used by chat
 		// speaker labels too, so the input gutter matches the rest

packages/tui/view.go

@@ -132,6 +132,12 @@ type View struct {
 	// the map when a turn ends.
 	liveBodyHigh map[string]int
 
+	// FlatTools renders tool calls without the bordered panel: a quiet
+	// header line per call plus indented, frameless output. The
+	// truncation/expand behaviour and theme colors are unchanged.
+	// False (the default) keeps the bordered box.
+	FlatTools bool
+
 	// ExpandAll forces every long tool result to render in full.
 	// Toggled from the tui by ctrl+o. When false, results longer than
 	// ToolCollapseLines collapse to ToolCollapsePreview lines plus a
@@ -706,6 +712,17 @@ func (v *View) renderMessage(m provider.Message, width int, turnOpen bool) []str
 				// from the matching ToolCallBlock so multiple calls
 				// in one assistant message render as N adjacent boxes
 				// instead of stacking unclosed top edges.
+				if v.FlatTools {
+					lines = append(lines, flatToolHeader(v.Theme, label, width))
+					if tr.IsError {
+						lines = append(lines, flatToolBody(v.Theme, v.Theme.FG256(color, "  error")))
+					}
+					for _, line := range v.renderToolResultContent(tr.Content, width, color, path, startLine) {
+						_, stripped := parseImageFootprint(line)
+						lines = append(lines, flatToolBody(v.Theme, stripped))
+					}
+					continue
+				}
 				lines = append(lines, toolBoxTop(v.Theme, label, width))
 				lines = append(lines, toolBoxSide(v.Theme, "", width))
 				if tr.IsError {
@@ -774,6 +791,14 @@ func (v *View) renderToolCall(tc ToolCallView, width int) []string {
 				}
 				v.liveBodyHigh[tc.ID] = high
 			}
+			if v.FlatTools {
+				for len(body) < high {
+					body = append(body, "")
+				}
+				lines = append(lines, flatToolHeader(v.Theme, label, width))
+				lines = append(lines, body...)
+				return lines
+			}
 			for len(body) < high {
 				body = append(body, toolBoxSide(v.Theme, "", width))
 			}
@@ -790,6 +815,10 @@ func (v *View) renderToolCall(tc ToolCallView, width int) []string {
 	// directly closed by the bottom. Avoids a blank interior row
 	// for no-output tools.
 	if tc.Result == "" {
+		if v.FlatTools {
+			lines = append(lines, flatToolHeader(v.Theme, label, width))
+			return lines
+		}
 		lines = append(lines, toolBoxTop(v.Theme, label, width))
 		lines = append(lines, toolBoxBottom(v.Theme, width))
 		return lines
@@ -800,12 +829,21 @@ func (v *View) renderToolCall(tc ToolCallView, width int) []string {
 	// vertical edges; bottom edge closes the box. Blank interior
 	// rows after the top and before the bottom give the body a bit
 	// of breathing room from the corners.
-	lines = append(lines, toolBoxTop(v.Theme, label, width))
-	lines = append(lines, toolBoxSide(v.Theme, "", width))
 	color := v.Theme.ToolOut
 	if tc.Error {
 		color = v.Theme.Error
 	}
+	if v.FlatTools {
+		lines = append(lines, flatToolHeader(v.Theme, label, width))
+		body := toolResultBlock(v.Theme, tc.Result, flatToolBodyRenderWidth(width), color)
+		for _, l := range v.collapseToolBody(body, false) {
+			_, stripped := parseImageFootprint(l)
+			lines = append(lines, flatToolBody(v.Theme, stripped))
+		}
+		return lines
+	}
+	lines = append(lines, toolBoxTop(v.Theme, label, width))
+	lines = append(lines, toolBoxSide(v.Theme, "", width))
 	body := toolResultBlock(v.Theme, tc.Result, toolBoxBodyRenderWidth(width), color)
 	for _, l := range v.collapseToolBody(body, false) {
 		imgCells, stripped := parseImageFootprint(l)
@@ -863,6 +901,9 @@ func (v *View) renderLiveToolBody(tc ToolCallView, width int) []string {
 
 func (v *View) renderLiveBashCommand(command string, width int) []string {
 	inner := toolBoxBodyRenderWidth(width)
+	if v.FlatTools {
+		inner = flatToolBodyRenderWidth(width)
+	}
 	prompt := v.Theme.FG256(v.Theme.Muted, "$ ")
 	var out []string
 	for i, line := range strings.Split(command, "\n") {
@@ -896,6 +937,13 @@ func (v *View) renderLiveBashCommand(command string, width int) []string {
 func (v *View) wrapLiveBody(body []string, width int) []string {
 	body = v.collapseToolBody(body, false)
 	out := make([]string, 0, len(body))
+	if v.FlatTools {
+		for _, l := range body {
+			_, stripped := parseImageFootprint(l)
+			out = append(out, flatToolBody(v.Theme, stripped))
+		}
+		return out
+	}
 	for _, l := range body {
 		imgCells, stripped := parseImageFootprint(l)
 		if hasImageEscapeLine(stripped) {
@@ -994,6 +1042,49 @@ func splitToolLabel(label string) (name, rest string) {
 	return label[:idx], label[idx:]
 }
 
+// flatToolHeader renders the boxless header line for a tool call:
+//
+//	▌ bash xcrun simctl list devices
+//
+// It carries the same information as toolBoxTop (tool name + short
+// args) but drops the frame: a single accent gutter glyph, the tool
+// name in the foreground color, and the argument summary muted. The
+// line is left-aligned at the same column the box's opening corner
+// used (toolBoxOuterMargin) so flat and box renders share a column.
+func flatToolHeader(th Theme, label string, width int) string {
+	label = oneLineToolLabel(label)
+	name, rest := splitToolLabel(label)
+	margin := strings.Repeat(" ", toolBoxOuterMargin)
+	gutter := th.FG256(th.Accent, "▌") + " "
+	// Budget the visible text to the content width so a very long
+	// argument summary doesn't run off the right edge; truncate with
+	// an ellipsis like the box header does.
+	avail := width - toolBoxOuterMargin - visibleWidth("▌ ")
+	if avail < 12 {
+		avail = 12
+	}
+	if visibleWidth(name+rest) > avail {
+		over := visibleWidth(name+rest) - avail
+		runes := []rune(rest)
+		if over+3 < len(runes) {
+			rest = string(runes[:len(runes)-over-3]) + "..."
+		} else if visibleWidth(name) <= avail {
+			rest = ""
+		}
+	}
+	return margin + gutter + th.FG256(th.FG, name) + th.FG256(th.Muted, rest)
+}
+
+// flatToolBody indents a single body line for boxless rendering. It
+// trims the same leading padding box bodies do, then prepends a fixed
+// gutter indent so output sits in a readable column under the header
+// without any vertical frame. ANSI styling in the line is preserved.
+func flatToolBody(th Theme, line string) string {
+	_ = th
+	line = trimLeadingSpaces(line, toolBoxBodyTrimLeft)
+	return strings.Repeat(" ", toolBoxOuterMargin+2) + line
+}
+
 // toolBoxBottom renders the bottom edge of a tool block:
 //
 //	└─────────────────────────────────────────────────────────────────────────────┘
@@ -1080,6 +1171,20 @@ func toolBoxBodyRenderWidth(width int) int {
 	return inner + toolBoxBodyTrimLeft
 }
 
+// flatToolBodyRenderWidth is the width body renderers should target in
+// flat mode. There's no box frame, just the flatToolBody indent
+// (toolBoxOuterMargin+2 cells), so the renderable width is the
+// terminal width minus that indent. Renderers emit a 4-cell indent of
+// their own which flatToolBody trims toolBoxBodyTrimLeft cells from,
+// so add that back like toolBoxBodyRenderWidth does.
+func flatToolBodyRenderWidth(width int) int {
+	inner := width - (toolBoxOuterMargin + 2)
+	if inner < 1 {
+		inner = 1
+	}
+	return inner + toolBoxBodyTrimLeft
+}
+
 // toolBoxSide wraps a single body line with vertical box edges:
 //
 //	│  foo bar baz                                            │
@@ -1202,6 +1307,9 @@ func (v *View) renderToolResultContent(blocks []provider.Content, width, color i
 		switch bb := b.(type) {
 		case provider.TextBlock:
 			bodyWidth := toolBoxBodyRenderWidth(width)
+			if v.FlatTools {
+				bodyWidth = flatToolBodyRenderWidth(width)
+			}
 			body = append(body, v.renderToolText(bb.Text, bodyWidth, color, sourcePath, startLine)...)
 		case provider.ImageBlock:
 			hasImage = true

packages/tui/view_flat_tools_test.go

@@ -0,0 +1,136 @@
+package tui
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/patriceckhart/zot/packages/provider"
+)
+
+// boxGlyphs are the runes that only appear when a tool call is drawn
+// inside the bordered panel. Flat mode must emit none of them.
+const boxGlyphs = "┌└│┐┘"
+
+func assertNoBoxGlyphs(t *testing.T, plain string) {
+	t.Helper()
+	if strings.ContainsAny(plain, boxGlyphs) {
+		t.Fatalf("flat render still contains box glyphs:\n%s", plain)
+	}
+}
+
+func TestFlatToolRenderDropsBorders(t *testing.T) {
+	args := json.RawMessage(`{"command":"echo hi"}`)
+	v := View{
+		Theme:     Dark,
+		FlatTools: true,
+		ToolCalls: []ToolCallView{
+			{ID: "toolu_1", Name: "bash", Args: ShortArgs("bash", args), Result: "hi\n"},
+		},
+	}
+	plain := stripANSI(strings.Join(v.Build(80), "\n"))
+	assertNoBoxGlyphs(t, plain)
+	if !strings.Contains(plain, "bash") {
+		t.Fatalf("flat header lost the tool name:\n%s", plain)
+	}
+	if !strings.Contains(plain, "hi") {
+		t.Fatalf("flat render lost the output:\n%s", plain)
+	}
+}
+
+// The box render of the same call still has borders — the toggle is
+// what changes, not the data.
+func TestBoxToolRenderKeepsBorders(t *testing.T) {
+	args := json.RawMessage(`{"command":"echo hi"}`)
+	v := View{
+		Theme: Dark,
+		ToolCalls: []ToolCallView{
+			{ID: "toolu_1", Name: "bash", Args: ShortArgs("bash", args), Result: "hi\n"},
+		},
+	}
+	plain := stripANSI(strings.Join(v.Build(80), "\n"))
+	if !strings.ContainsAny(plain, boxGlyphs) {
+		t.Fatalf("box render should contain border glyphs:\n%s", plain)
+	}
+}
+
+func TestFlatToolRenderLiveBodyHasNoBorders(t *testing.T) {
+	args := json.RawMessage(`{"command":"printf 'start' && sleep 60"}`)
+	v := View{
+		Theme:     Dark,
+		FlatTools: true,
+		ToolCalls: []ToolCallView{
+			{ID: "toolu_1", Name: "bash", Args: ShortArgs("bash", args), RawJSONBuf: string(args)},
+		},
+	}
+	plain := stripANSI(strings.Join(v.BuildLive(100), "\n"))
+	assertNoBoxGlyphs(t, plain)
+	if !strings.Contains(plain, "$ printf 'start'") {
+		t.Fatalf("flat live body lost the streamed command:\n%s", plain)
+	}
+}
+
+// Truncation + the ctrl+o expand footer must survive flat mode.
+func TestFlatToolRenderKeepsTruncationFooter(t *testing.T) {
+	var b strings.Builder
+	for i := 0; i < ToolCollapseLines+50; i++ {
+		fmt.Fprintf(&b, "line %d\n", i)
+	}
+	args := json.RawMessage(`{"command":"seq 999"}`)
+	collapsed := View{
+		Theme:     Dark,
+		FlatTools: true,
+		ToolCalls: []ToolCallView{
+			{ID: "toolu_1", Name: "bash", Args: ShortArgs("bash", args), Result: b.String()},
+		},
+	}
+	plain := stripANSI(strings.Join(collapsed.Build(80), "\n"))
+	assertNoBoxGlyphs(t, plain)
+	if !strings.Contains(plain, "ctrl+o to expand") {
+		t.Fatalf("flat render dropped the truncation footer:\n%s", plain)
+	}
+
+	// ExpandAll shows everything and still has no borders.
+	collapsed.ExpandAll = true
+	full := stripANSI(strings.Join(collapsed.Build(80), "\n"))
+	assertNoBoxGlyphs(t, full)
+	if strings.Contains(full, "ctrl+o to expand") {
+		t.Fatalf("expanded flat render should not show the footer:\n%s", full)
+	}
+	if !strings.Contains(full, fmt.Sprintf("line %d", ToolCollapseLines+40)) {
+		t.Fatalf("expanded flat render is missing later lines:\n%s", full)
+	}
+}
+
+// A finished tool result that comes back as a RoleTool message (the
+// transcript path, distinct from the in-flight ToolCalls path) also
+// renders flat.
+func TestFlatToolRenderTranscriptResult(t *testing.T) {
+	callArgs := json.RawMessage(`{"command":"echo done"}`)
+	v := View{
+		Theme:     Dark,
+		FlatTools: true,
+		Messages: []provider.Message{
+			{
+				Role: provider.RoleAssistant,
+				Content: []provider.Content{
+					provider.ToolCallBlock{ID: "toolu_1", Name: "bash", Arguments: callArgs},
+				},
+			},
+			{
+				Role: provider.RoleTool,
+				Content: []provider.Content{
+					provider.ToolResultBlock{CallID: "toolu_1", Content: []provider.Content{
+						provider.TextBlock{Text: "done"},
+					}},
+				},
+			},
+		},
+	}
+	plain := stripANSI(strings.Join(v.Build(80), "\n"))
+	assertNoBoxGlyphs(t, plain)
+	if !strings.Contains(plain, "bash") || !strings.Contains(plain, "done") {
+		t.Fatalf("flat transcript result lost header or output:\n%s", plain)
+	}
+}