feat(tui): show compaction summary with Ctrl-O

.changeset/compaction-summary-toggle.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Show compaction summaries in the TUI after compaction. Press Ctrl-O to show or hide the summary.

apps/kimi-code/src/tui/components/dialogs/compaction.ts

@@ -24,6 +24,7 @@ const BLINK_INTERVAL = 500;
 export class CompactionComponent extends Container {
   private readonly ui: TUI | undefined;
   private readonly headerText: Text;
+  private instructionText: Text | undefined;
   private readonly instruction: string | undefined;
   private readonly tip: string | undefined;
   private blinkOn = true;
@@ -32,6 +33,9 @@ export class CompactionComponent extends Container {
   private canceled = false;
   private tokensBefore: number | undefined;
   private tokensAfter: number | undefined;
+  private summary: string | undefined;
+  private summaryText: Text | undefined;
+  private expanded = false;
 
   constructor(ui?: TUI, instruction?: string | undefined, tip?: string) {
     super();
@@ -51,32 +55,48 @@ export class CompactionComponent extends Container {
 
   private addInstructionChild(): void {
     if (this.instruction !== undefined) {
-      this.addChild(new Text(currentTheme.dim(`  ${this.instruction}`), 0, 0));
+      this.instructionText = new Text(currentTheme.dim(`  ${this.instruction}`), 0, 0);
+      this.addChild(this.instructionText);
     }
   }
 
+  private removeInstructionChild(): void {
+    if (this.instructionText === undefined) return;
+    const index = this.children.indexOf(this.instructionText);
+    if (index !== -1) {
+      this.children.splice(index, 1);
+    }
+    this.instructionText = undefined;
+  }
+
   override invalidate(): void {
     // Repaint the header with the active palette (it caches ANSI codes).
     this.headerText.setText(this.buildHeader());
-    // Rebuild instruction line with fresh theme colours.
-    if (this.instruction !== undefined) {
-      // Remove the last child if it is the instruction line (it is always
-      // added after headerText and Spacer).
-      if (this.children.length > 2) {
-        this.children.pop();
-      }
-      this.addInstructionChild();
+    // Rebuild instruction and summary text with fresh theme colours, preserving
+    // header → instruction → summary child order.
+    const expanded = this.expanded;
+    this.removeInstructionChild();
+    if (expanded) {
+      this.removeSummaryChild();
+    }
+    this.addInstructionChild();
+    if (expanded) {
+      this.addSummaryChild();
     }
     super.invalidate();
   }
 
-  markDone(tokensBefore?: number, tokensAfter?: number): void {
+  markDone(tokensBefore?: number, tokensAfter?: number, summary?: string): void {
     if (this.done || this.canceled) return;
     this.done = true;
     this.tokensBefore = tokensBefore;
     this.tokensAfter = tokensAfter;
+    this.summary = summary;
     this.stopBlink();
     this.headerText.setText(this.buildHeader());
+    if (this.expanded) {
+      this.addSummaryChild();
+    }
     this.ui?.requestRender();
   }
 
@@ -88,6 +108,39 @@ export class CompactionComponent extends Container {
     this.ui?.requestRender();
   }
 
+  setExpanded(expanded: boolean): void {
+    if (this.expanded === expanded) return;
+    this.expanded = expanded;
+    if (expanded) {
+      this.addSummaryChild();
+    } else {
+      this.removeSummaryChild();
+    }
+    this.headerText.setText(this.buildHeader());
+    this.ui?.requestRender();
+  }
+
+  private addSummaryChild(): void {
+    if (this.summaryText !== undefined || this.summary === undefined || this.summary.length === 0) {
+      return;
+    }
+    const indentedSummary = this.summary
+      .split('\n')
+      .map((line) => `  ${line}`)
+      .join('\n');
+    this.summaryText = new Text(currentTheme.dim(indentedSummary), 0, 0);
+    this.addChild(this.summaryText);
+  }
+
+  private removeSummaryChild(): void {
+    if (this.summaryText === undefined) return;
+    const index = this.children.indexOf(this.summaryText);
+    if (index !== -1) {
+      this.children.splice(index, 1);
+    }
+    this.summaryText = undefined;
+  }
+
   dispose(): void {
     this.stopBlink();
   }
@@ -100,7 +153,11 @@ export class CompactionComponent extends Container {
         this.tokensBefore !== undefined && this.tokensAfter !== undefined
           ? currentTheme.dim(` (${String(this.tokensBefore)} → ${String(this.tokensAfter)} tokens)`)
           : '';
-      return `${bullet}${label}${detail}`;
+      const shortcutHint =
+        this.summary !== undefined && this.summary.length > 0
+          ? currentTheme.dim(` (Ctrl-O to ${this.expanded ? 'hide' : 'show'} compaction summary)`)
+          : '';
+      return `${bullet}${label}${detail}${shortcutHint}`;
     }
     if (this.canceled) {
       const bullet = currentTheme.fg('warning', STATUS_BULLET);

apps/kimi-code/src/tui/components/dialogs/help-panel.ts

@@ -33,7 +33,7 @@ export interface HelpPanelCommand {
 export const DEFAULT_KEYBOARD_SHORTCUTS: readonly KeyboardShortcut[] = [
   { keys: 'Shift-Tab', description: 'Toggle plan mode' },
   { keys: 'Ctrl-G', description: 'Edit in external editor ($VISUAL / $EDITOR)' },
-  { keys: 'Ctrl-O', description: 'Toggle tool output expansion' },
+  { keys: 'Ctrl-O', description: 'Toggle tool output / compaction summary expansion' },
   { keys: 'Ctrl-T', description: 'Expand / collapse the todo list (when truncated)' },
   { keys: 'Ctrl-S', description: 'Steer — inject a follow-up during streaming' },
   { keys: 'Shift-Enter / Ctrl-J', description: 'Insert newline' },

apps/kimi-code/src/tui/controllers/session-event-handler.ts

@@ -984,7 +984,11 @@ export class SessionEventHandler {
     event: CompactionCompletedEvent,
     sendQueued: (item: QueuedMessage) => void,
   ): void {
-    this.host.streamingUI.endCompaction(event.result.tokensBefore, event.result.tokensAfter);
+    this.host.streamingUI.endCompaction(
+      event.result.tokensBefore,
+      event.result.tokensAfter,
+      event.result.summary,
+    );
     this.finishCompaction(sendQueued);
   }
 

apps/kimi-code/src/tui/controllers/session-replay.ts

@@ -472,6 +472,7 @@ export class SessionReplayRenderer {
     this.host.appendTranscriptEntry({
       ...replayEntry(context, 'status', 'Compaction complete', 'plain'),
       compactionData: {
+        summary: record.result.summary,
         tokensBefore: record.result.tokensBefore,
         tokensAfter: record.result.tokensAfter,
         instruction: record.instruction,

apps/kimi-code/src/tui/controllers/streaming-ui.ts

@@ -724,13 +724,16 @@ export class StreamingUIController {
     const block = new CompactionComponent(state.ui, instruction, currentWorkingTip()?.text);
     this._activeCompactionBlock = block;
     state.transcriptContainer.addChild(block);
+    if (state.toolOutputExpanded) {
+      block.setExpanded(true);
+    }
     state.ui.requestRender();
   }
 
-  endCompaction(tokensBefore?: number, tokensAfter?: number): void {
+  endCompaction(tokensBefore?: number, tokensAfter?: number, summary?: string): void {
     const block = this._activeCompactionBlock;
     if (block === undefined) return;
-    block.markDone(tokensBefore, tokensAfter);
+    block.markDone(tokensBefore, tokensAfter, summary);
     this._activeCompactionBlock = undefined;
     this.host.state.ui.requestRender();
   }

apps/kimi-code/src/tui/kimi-tui.ts

@@ -1740,7 +1740,10 @@ export class KimiTUI {
       if (data.result === 'cancelled') {
         block.markCanceled();
       } else {
-        block.markDone(data.tokensBefore, data.tokensAfter);
+        block.markDone(data.tokensBefore, data.tokensAfter, data.summary);
+        if (this.state.toolOutputExpanded) {
+          block.setExpanded(true);
+        }
       }
       return block;
     }

apps/kimi-code/src/tui/types.ts

@@ -119,6 +119,7 @@ export interface BackgroundAgentStatusData {
 
 export interface CompactionTranscriptData {
   readonly result?: 'cancelled';
+  readonly summary?: string;
   readonly tokensBefore?: number;
   readonly tokensAfter?: number;
   readonly instruction?: string;

apps/kimi-code/test/tui/components/dialogs/compaction.test.ts

@@ -50,6 +50,7 @@ describe('CompactionComponent', () => {
 
       expect(text).toContain('Compaction complete');
       expect(text).not.toContain('Tip:');
+      expect(text).not.toContain('Ctrl-O');
     } finally {
       component.dispose();
     }
@@ -70,6 +71,83 @@ describe('CompactionComponent', () => {
     }
   });
 
+  it('keeps the completed compaction summary hidden until expanded', () => {
+    const component = new CompactionComponent();
+
+    try {
+      component.markDone(120, 24, 'Keep the src/tui compaction notes.');
+      const collapsed = component.render(120).map(strip).join('\n');
+
+      expect(collapsed).toContain('Compaction complete');
+      expect(collapsed).toContain('120 → 24 tokens');
+      expect(collapsed).toContain('Ctrl-O to show compaction summary');
+      expect(collapsed).not.toContain('Keep the src/tui compaction notes.');
+
+      component.setExpanded(true);
+      const expanded = component.render(120).map(strip).join('\n');
+
+      expect(expanded).toContain('Compaction complete');
+      expect(expanded).toContain('Ctrl-O to hide compaction summary');
+      expect(expanded).toContain('Keep the src/tui compaction notes.');
+    } finally {
+      component.dispose();
+    }
+  });
+
+  it('hides the compaction summary again when collapsed', () => {
+    const component = new CompactionComponent();
+
+    try {
+      component.markDone(120, 24, 'Keep the src/tui compaction notes.');
+      component.setExpanded(true);
+      component.setExpanded(false);
+      const text = component.render(120).map(strip).join('\n');
+
+      expect(text).toContain('Compaction complete');
+      expect(text).toContain('Ctrl-O to show compaction summary');
+      expect(text).not.toContain('Ctrl-O to hide compaction summary');
+      expect(text).not.toContain('Keep the src/tui compaction notes.');
+    } finally {
+      component.dispose();
+    }
+  });
+
+  it('preserves the expanded summary when invalidating with an instruction', () => {
+    const component = new CompactionComponent(undefined, 'keep the recent files only');
+
+    try {
+      component.markDone(120, 24, 'Keep the src/tui compaction notes.');
+      component.setExpanded(true);
+      component.invalidate();
+      const text = component.render(120).map(strip).join('\n');
+
+      expect(text).toContain('keep the recent files only');
+      expect(text).toContain('Keep the src/tui compaction notes.');
+      expect(text.match(/keep the recent files only/g)).toHaveLength(1);
+    } finally {
+      component.dispose();
+    }
+  });
+
+  it('keeps expanded summary child order on invalidate', () => {
+    const component = new CompactionComponent(undefined, 'keep the recent files only');
+
+    try {
+      component.markDone(120, 24, 'Keep the src/tui compaction notes.');
+      component.setExpanded(true);
+      currentTheme.setPalette(lightColors);
+      component.invalidate();
+      const text = component.render(120).map(strip).join('\n');
+
+      expect(text).toContain('Keep the src/tui compaction notes.');
+      expect(text.indexOf('keep the recent files only')).toBeLessThan(
+        text.indexOf('Keep the src/tui compaction notes.'),
+      );
+    } finally {
+      component.dispose();
+    }
+  });
+
   it('repaints the header with the active palette on invalidate', () => {
     // Force truecolor so palette differences surface as ANSI codes even when
     // the test runner has no TTY.

apps/kimi-code/test/tui/kimi-tui-message-flow.test.ts

@@ -2023,6 +2023,83 @@ command = "vim"
     }
   });
 
+  it('stores the live compaction summary and expands it with tool output expansion', async () => {
+    const { driver } = await makeDriver();
+    const sendQueued = vi.fn();
+
+    driver.sessionEventHandler.handleEvent(
+      {
+        type: 'compaction.started',
+        agentId: 'main',
+        sessionId: 'ses-1',
+        trigger: 'manual',
+      } as Event,
+      sendQueued,
+    );
+
+    driver.sessionEventHandler.handleEvent(
+      {
+        type: 'compaction.completed',
+        agentId: 'main',
+        sessionId: 'ses-1',
+        result: {
+          summary: 'Keep the src/tui compaction notes.',
+          compactedCount: 4,
+          tokensBefore: 120,
+          tokensAfter: 24,
+        },
+      } as Event,
+      sendQueued,
+    );
+
+    const collapsed = driver.state.transcriptContainer.render(120).map(stripSgr).join('\n');
+    expect(collapsed).toContain('Compaction complete');
+    expect(collapsed).not.toContain('Keep the src/tui compaction notes.');
+
+    driver.state.editor.onToggleToolExpand?.();
+
+    const expanded = driver.state.transcriptContainer.render(120).map(stripSgr).join('\n');
+    expect(driver.state.toolOutputExpanded).toBe(true);
+    expect(expanded).toContain('Keep the src/tui compaction notes.');
+  });
+
+  it('honors existing tool output expansion when a compaction block is created', async () => {
+    const { driver } = await makeDriver();
+    const sendQueued = vi.fn();
+
+    driver.state.editor.onToggleToolExpand?.();
+    expect(driver.state.toolOutputExpanded).toBe(true);
+
+    driver.sessionEventHandler.handleEvent(
+      {
+        type: 'compaction.started',
+        agentId: 'main',
+        sessionId: 'ses-1',
+        trigger: 'manual',
+      } as Event,
+      sendQueued,
+    );
+
+    driver.sessionEventHandler.handleEvent(
+      {
+        type: 'compaction.completed',
+        agentId: 'main',
+        sessionId: 'ses-1',
+        result: {
+          summary: 'Keep the src/tui compaction notes.',
+          compactedCount: 4,
+          tokensBefore: 120,
+          tokensAfter: 24,
+        },
+      } as Event,
+      sendQueued,
+    );
+
+    const transcript = driver.state.transcriptContainer.render(120).map(stripSgr).join('\n');
+    expect(transcript).toContain('Compaction complete');
+    expect(transcript).toContain('Keep the src/tui compaction notes.');
+  });
+
   it('renders an error instead of prompting when no model is selected', async () => {
     const { driver, session } = await makeDriver();
     driver.state.appState.model = '';