diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index d027da5be..8ce20eb81 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -1,10 +1,15 @@
 # Changelog
 
 ## [Unreleased]
+### Added
+
+- Added a `ChatBlock` transcript primitive (`modes/components/chat-block.ts`) and a single `ctx.present(...)` sink (with `ctx.resetTranscript()`) so chat output is mounted in one place instead of the repeated `chatContainer.addChild(...)` + `ui.requestRender()` pattern scattered across controllers. `ChatBlock` carries a React/Svelte-style lifecycle — `onMount` starts effects, `onCleanup` registers teardown, `finish()` self-completes (stops timers and freezes the block at its final content), and `dispose()`/`resetTranscript()` tears everything down — so animated blocks own their own resources instead of leaking `setInterval`/`requestRender` bookkeeping into callers. The MCP "Connecting…" spinner is now such a block.
+
 ### Changed
 
 - Changed the directory grouping for `find`, `search`, `ast_grep`, `ast_edit`, and `lsp` diagnostics from a single flat `# dir/` heading per immediate directory to a multi-level tree that folds the common path prefix into one heading. Previously every group repeated the full directory path — so results rooted outside cwd printed the absolute prefix (e.g. `/Users/me/proj/`) on every heading and nested directories were never collapsed. Now a single-child directory chain folds into one heading (`# packages/pkg/src/`, including an absolute root for out-of-cwd results), subdirectories nest one `#` deeper (`## nested/` → `### child.ts`), and each directory's own files are listed before its subdirectories. TUI hyperlink reconstruction tracks the nested directory stack across the whole output so file and code-frame links keep resolving to the correct absolute paths.
 - Changed the plan-mode approval surface from an inline transcript block plus a separate bottom selector into a single fullscreen overlay (like `/copy`). The overlay owns its entire content via `ScrollView`: the plan renders once as Markdown and scrolls inside the outlined box (PageUp/PageDown, g/G), with the approval options and the model-tier slider beneath it. ↑/↓ move the option cursor, ←/→ drive the slider, Enter confirms, the external-editor key opens the plan, and Esc cancels — so a tall plan no longer competes with the selector for vertical space or clips its head on ED3-risk terminals.
+- Changed the interactive controllers (command, MCP, selector, extension-UI, event), debug panels, and the status/error/warning helpers to render chat output through `ctx.present(...)` instead of appending to `chatContainer` and calling `ui.requestRender()` directly; transcript rebuilds dispose live blocks via `ctx.resetTranscript()` so animated blocks' timers stop on reset.
 
 ### Fixed
 
@@ -13,6 +18,7 @@
 - Fixed `omp dry-balance --bench` flooding the terminal with staircased, duplicated spinner/status lines (and an indented summary) when the tty has ONLCR/OPOST disabled (raw mode). The interactive progress region separated rows with a bare LF and repositioned with a column-preserving `\x1b[<n>A` cursor-up, both of which only land at column 0 when the terminal translates LF→CRLF; with that translation off, every 80 ms redraw cascaded down and to the right into scrollback. The live region now carriage-returns before every cleared row, terminates each row with CRLF, and caps each row to the terminal width so a wrapped line cannot desync the cursor-up from the logical line count.
 - Fixed inconsistent vertical spacing between transcript blocks: some blocks (tool results from `search`/`find` and other renderer-backed tools) rendered with a doubled gap (a leading `Spacer` plus the content box's own `paddingY`), while others (the grouped `read` card, file-mention lists, IRC cards) rendered with no gap at all. Vertical spacing is now owned entirely by the chat renderer: `TranscriptContainer` strips each block's plain-blank top/bottom edges and inserts exactly one blank line between consecutive blocks, so every block is separated by a single consistent gap regardless of which component produced it. Individual components (assistant/user/tool/read-group/bash/eval/skill/custom/hook/compaction/branch/todo-reminder/plan-review messages) no longer emit their own leading `Spacer`/`paddingY` for separation, and multi-row groups (IRC cards, file-mention lists, completed-job batches, and the bordered command/`/changelog`/`/context`/version/OAuth/debug panels) are wrapped as single `TranscriptBlock` children so the renderer spaces them as one unit. Background-colored box padding is preserved as block-internal design.
 - Fixed `resolve` with `action: "discard"` surfacing a hard `isError` "No pending action to resolve" failure to the model when the agent asked to cancel a staged action (e.g. an `ast_edit` preview) but nothing was pending. A discard is a request to reach the "no staged change" end-state, which already holds in that case, so it is now honored as a successful cancellation (`"Nothing to discard; no pending action remains."` with `details.action: "discard"`) instead of an error. `action: "apply"` with no pending action still errors.
+- Fixed the collapsed tool-output expand hint rendering double brackets (e.g. `((Ctrl+O for more))`) — the `EXPAND_HINT` text already carried its own parentheses and then `formatExpandHint` wrapped it again with the theme's bracket glyphs. The hint now resolves the key actually bound to `app.tools.expand` at render time and reads `⟨<key>: Expand⟩` (e.g. `⟨Ctrl+O: Expand⟩`), so a single bracket pair surrounds it and a user remap of the expand keybinding is reflected instead of a hard-coded `Ctrl+O`.
 
 ## [15.10.0] - 2026-06-06
 
diff --git a/packages/coding-agent/src/debug/index.ts b/packages/coding-agent/src/debug/index.ts
index 813afa65b..17840cc4b 100644
--- a/packages/coding-agent/src/debug/index.ts
+++ b/packages/coding-agent/src/debug/index.ts
@@ -157,8 +157,7 @@ export class DebugSelectorComponent extends Container {
 		block.addChild(
 			new Text(theme.fg("muted", "Reproduce the performance issue, then press Enter to stop profiling."), 1, 0),
 		);
-		this.ctx.chatContainer.addChild(block);
-		this.ctx.ui.requestRender();
+		this.ctx.present(block);
 
 		// Wait for Enter keypress
 		const { promise, resolve } = Promise.withResolvers<void>();
@@ -207,14 +206,12 @@ export class DebugSelectorComponent extends Container {
 			block.addChild(new Text(theme.fg("success", `${theme.status.success} Performance report saved`), 1, 0));
 			block.addChild(new Text(theme.fg("dim", formatFileHyperlink(result.path)), 1, 0));
 			block.addChild(new Text(theme.fg("dim", `Files: ${result.files.length}`), 1, 0));
-			this.ctx.chatContainer.addChild(block);
+			this.ctx.present(block);
 		} catch (err) {
 			loader.stop();
 			this.ctx.statusContainer.clear();
 			this.ctx.showError(`Failed to create report: ${err instanceof Error ? err.message : String(err)}`);
 		}
-
-		this.ctx.ui.requestRender();
 	}
 
 	async #handleWorkReport(): Promise<void> {
@@ -232,15 +229,13 @@ export class DebugSelectorComponent extends Container {
 
 			openPath(tmpPath);
 
-			this.ctx.chatContainer.addChild(new Spacer(1));
-			this.ctx.chatContainer.addChild(
+			this.ctx.present([
+				new Spacer(1),
 				new Text(theme.fg("dim", `Opened flamegraph (${workProfile.sampleCount} samples)`), 1, 0),
-			);
+			]);
 		} catch (err) {
 			this.ctx.showError(`Failed to open profile: ${err instanceof Error ? err.message : String(err)}`);
 		}
-
-		this.ctx.ui.requestRender();
 	}
 
 	async #handleDumpReport(): Promise<void> {
@@ -267,14 +262,12 @@ export class DebugSelectorComponent extends Container {
 			block.addChild(new Text(theme.fg("success", `${theme.status.success} Report bundle saved`), 1, 0));
 			block.addChild(new Text(theme.fg("dim", formatFileHyperlink(result.path)), 1, 0));
 			block.addChild(new Text(theme.fg("dim", `Files: ${result.files.length}`), 1, 0));
-			this.ctx.chatContainer.addChild(block);
+			this.ctx.present(block);
 		} catch (err) {
 			loader.stop();
 			this.ctx.statusContainer.clear();
 			this.ctx.showError(`Failed to create report: ${err instanceof Error ? err.message : String(err)}`);
 		}
-
-		this.ctx.ui.requestRender();
 	}
 
 	async #handleMemoryReport(): Promise<void> {
@@ -305,14 +298,12 @@ export class DebugSelectorComponent extends Container {
 			block.addChild(new Text(theme.fg("success", `${theme.status.success} Memory report saved`), 1, 0));
 			block.addChild(new Text(theme.fg("dim", formatFileHyperlink(result.path)), 1, 0));
 			block.addChild(new Text(theme.fg("dim", `Files: ${result.files.length}`), 1, 0));
-			this.ctx.chatContainer.addChild(block);
+			this.ctx.present(block);
 		} catch (err) {
 			loader.stop();
 			this.ctx.statusContainer.clear();
 			this.ctx.showError(`Failed to create report: ${err instanceof Error ? err.message : String(err)}`);
 		}
-
-		this.ctx.ui.requestRender();
 	}
 
 	async #handleViewLogs(): Promise<void> {
@@ -368,12 +359,10 @@ export class DebugSelectorComponent extends Container {
 			block.addChild(new DynamicBorder());
 			block.addChild(new Text(formatted, 1, 0));
 			block.addChild(new DynamicBorder());
-			this.ctx.chatContainer.addChild(block);
+			this.ctx.present(block);
 		} catch (err) {
 			this.ctx.showError(`Failed to collect system info: ${err instanceof Error ? err.message : String(err)}`);
 		}
-
-		this.ctx.ui.requestRender();
 	}
 
 	async #handleViewTerminalState(): Promise<void> {
@@ -388,8 +377,7 @@ export class DebugSelectorComponent extends Container {
 		block.addChild(new DynamicBorder());
 		block.addChild(new Text(formatted, 1, 0));
 		block.addChild(new DynamicBorder());
-		this.ctx.chatContainer.addChild(block);
-		this.ctx.ui.requestRender();
+		this.ctx.present(block);
 	}
 
 	async #handleViewProtocols(): Promise<void> {
@@ -408,15 +396,14 @@ export class DebugSelectorComponent extends Container {
 			TERMINAL.sendNotification(notification);
 		}
 
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		this.ctx.chatContainer.addChild(
+		this.ctx.present([
+			new Spacer(1),
 			new ProtocolProbeComponent({
 				image: buildSampleImage(),
 				imageBudget: this.ctx.ui.imageBudget,
 				notificationSuppressed: suppressed,
 			}),
-		);
-		this.ctx.ui.requestRender();
+		]);
 	}
 
 	async #handleTranscriptExport(): Promise<void> {
@@ -488,21 +475,19 @@ export class DebugSelectorComponent extends Container {
 			loader.stop();
 			this.ctx.statusContainer.clear();
 
-			this.ctx.chatContainer.addChild(new Spacer(1));
-			this.ctx.chatContainer.addChild(
+			this.ctx.present([
+				new Spacer(1),
 				new Text(
 					theme.fg("success", `${theme.status.success} Cleared ${result.removed} artifact directories`),
 					1,
 					0,
 				),
-			);
+			]);
 		} catch (err) {
 			loader.stop();
 			this.ctx.statusContainer.clear();
 			this.ctx.showError(`Failed to clear cache: ${err instanceof Error ? err.message : String(err)}`);
 		}
-
-		this.ctx.ui.requestRender();
 	}
 
 	#getResolvedSettings(): Record<string, unknown> {
diff --git a/packages/coding-agent/src/modes/components/chat-block.ts b/packages/coding-agent/src/modes/components/chat-block.ts
new file mode 100644
index 000000000..da79c2041
--- /dev/null
+++ b/packages/coding-agent/src/modes/components/chat-block.ts
@@ -0,0 +1,111 @@
+import { Container } from "@oh-my-pi/pi-tui";
+
+/**
+ * Capabilities a mounted {@link ChatBlock} may use against its host transcript.
+ * Kept minimal so blocks never reach into the full TUI/InteractiveMode surface.
+ */
+export interface ChatBlockHost {
+	/** Schedule a repaint of the transcript. */
+	requestRender(): void;
+}
+
+/**
+ * Lifecycle-aware transcript block — the "return a block, let the host mount it"
+ * primitive, modelled on React/Svelte component lifecycles.
+ *
+ * Producers build and return a `ChatBlock` instead of poking `chatContainer` and
+ * `ui.requestRender()` directly. The host (`ctx.present`) appends it and calls
+ * {@link mount}, which runs {@link onMount}; effects started there register
+ * teardown via {@link onCleanup}. The block repaints through {@link requestRender}
+ * — never touching the TUI — and tears down exactly once on {@link finish}
+ * (self-complete: stop the animation, keep the final frame in the transcript) or
+ * {@link dispose} (host discards it, e.g. a transcript reset).
+ *
+ * While mounted and unfinished a block reports `isTranscriptBlockFinalized() ===
+ * false` so {@link "../components/transcript-container".TranscriptContainer}
+ * keeps it in the live, repaintable region on ED3-risk terminals; after
+ * `finish()`/`dispose()` it reports `true` and freezes at its final content.
+ */
+export abstract class ChatBlock extends Container {
+	#host: ChatBlockHost | undefined;
+	#cleanups: Array<() => void> = [];
+	#active = false;
+	#disposed = false;
+
+	/**
+	 * Run setup after the block is in the transcript: start timers/subscriptions
+	 * and register their teardown with {@link onCleanup}. Default: no-op (a block
+	 * whose content is fixed at construction needs no mount work).
+	 */
+	protected onMount(): void {}
+
+	/**
+	 * Register a teardown to run on {@link finish}/{@link dispose}, à la a
+	 * `useEffect` cleanup. If the block is already disposed the cleanup runs
+	 * immediately so callers never leak.
+	 */
+	protected onCleanup(cleanup: () => void): void {
+		if (this.#disposed) {
+			cleanup();
+			return;
+		}
+		this.#cleanups.push(cleanup);
+	}
+
+	/** Ask the host to repaint. No-op before mount or after dispose. */
+	protected requestRender(): void {
+		this.#host?.requestRender();
+	}
+
+	/** True between {@link mount} and {@link finish}/{@link dispose}. */
+	protected get active(): boolean {
+		return this.#active;
+	}
+
+	/**
+	 * Host-only: attach the host and run {@link onMount}. Idempotent — a second
+	 * call (e.g. a transcript rebuild that re-presents the same instance) is a
+	 * no-op.
+	 */
+	mount(host: ChatBlockHost): void {
+		if (this.#host || this.#disposed) return;
+		this.#host = host;
+		this.#active = true;
+		this.onMount();
+	}
+
+	/**
+	 * Self-complete: stop ongoing effects and freeze the block at its current
+	 * content, leaving it rendered in the transcript. Use when the operation the
+	 * block represents finishes (connection resolved, download done).
+	 */
+	finish(): void {
+		if (!this.#active) return;
+		this.#active = false;
+		this.#runCleanups();
+		this.requestRender();
+	}
+
+	/**
+	 * Host-only teardown: release everything and propagate to children. Called
+	 * when the host permanently discards the block (transcript reset). Idempotent.
+	 */
+	override dispose(): void {
+		if (this.#disposed) return;
+		this.#disposed = true;
+		this.#active = false;
+		this.#runCleanups();
+		super.dispose();
+		this.#host = undefined;
+	}
+
+	/** Live blocks stay repaintable; finished/disposed ones may freeze. */
+	isTranscriptBlockFinalized(): boolean {
+		return !this.#active;
+	}
+
+	#runCleanups(): void {
+		const cleanups = this.#cleanups.splice(0);
+		for (const cleanup of cleanups) cleanup();
+	}
+}
diff --git a/packages/coding-agent/src/modes/controllers/command-controller-shared.ts b/packages/coding-agent/src/modes/controllers/command-controller-shared.ts
index 7ee9c9499..2e3eb6471 100644
--- a/packages/coding-agent/src/modes/controllers/command-controller-shared.ts
+++ b/packages/coding-agent/src/modes/controllers/command-controller-shared.ts
@@ -105,6 +105,5 @@ export function showCommandMessage(ctx: InteractiveModeContext, text: string): v
 	block.addChild(new DynamicBorder());
 	block.addChild(new Text(text, 1, 1));
 	block.addChild(new DynamicBorder());
-	ctx.chatContainer.addChild(block);
-	ctx.ui.requestRender();
+	ctx.present(block);
 }
diff --git a/packages/coding-agent/src/modes/controllers/command-controller.ts b/packages/coding-agent/src/modes/controllers/command-controller.ts
index 942392430..c19f93269 100644
--- a/packages/coding-agent/src/modes/controllers/command-controller.ts
+++ b/packages/coding-agent/src/modes/controllers/command-controller.ts
@@ -53,8 +53,7 @@ function showMarkdownPanel(ctx: InteractiveModeContext, title: string, markdown:
 	block.addChild(new Spacer(1));
 	block.addChild(new Markdown(markdown.trim(), 1, 1, getMarkdownTheme()));
 	block.addChild(new DynamicBorder());
-	ctx.chatContainer.addChild(block);
-	ctx.ui.requestRender();
+	ctx.present(block);
 }
 
 export class CommandController {
@@ -336,9 +335,7 @@ export class CommandController {
 			}
 		}
 
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		this.ctx.chatContainer.addChild(new Text(info, 1, 0));
-		this.ctx.ui.requestRender();
+		this.ctx.present([new Spacer(1), new Text(info, 1, 0)]);
 	}
 
 	async handleJobsCommand(): Promise<void> {
@@ -355,9 +352,7 @@ export class CommandController {
 
 		if (snapshot.running.length === 0 && snapshot.recent.length === 0) {
 			info += `\n${theme.fg("dim", "No async jobs yet.")}\n`;
-			this.ctx.chatContainer.addChild(new Spacer(1));
-			this.ctx.chatContainer.addChild(new Text(info, 1, 0));
-			this.ctx.ui.requestRender();
+			this.ctx.present([new Spacer(1), new Text(info, 1, 0)]);
 			return;
 		}
 
@@ -377,9 +372,7 @@ export class CommandController {
 			}
 		}
 
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		this.ctx.chatContainer.addChild(new Text(info.trimEnd(), 1, 0));
-		this.ctx.ui.requestRender();
+		this.ctx.present([new Spacer(1), new Text(info.trimEnd(), 1, 0)]);
 	}
 
 	async handleUsageCommand(reports?: UsageReport[] | null): Promise<void> {
@@ -405,9 +398,7 @@ export class CommandController {
 
 		const availableWidth = Math.max(40, (this.ctx.ui.terminal.columns ?? 100) - 2);
 		const output = renderUsageReports(usageReports, theme, Date.now(), availableWidth);
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		this.ctx.chatContainer.addChild(new Text(output, 1, 0));
-		this.ctx.ui.requestRender();
+		this.ctx.present([new Spacer(1), new Text(output, 1, 0)]);
 	}
 
 	async handleChangelogCommand(showFull = false): Promise<void> {
@@ -434,8 +425,7 @@ export class CommandController {
 		block.addChild(new Spacer(1));
 		block.addChild(new Markdown(changelogMarkdown + hint, 1, 1, getMarkdownTheme()));
 		block.addChild(new DynamicBorder());
-		this.ctx.chatContainer.addChild(block);
-		this.ctx.ui.requestRender();
+		this.ctx.present(block);
 	}
 
 	handleHotkeysCommand(): void {
@@ -461,8 +451,7 @@ export class CommandController {
 		block.addChild(new Spacer(1));
 		block.addChild(new Text(output, 1, 0));
 		block.addChild(new DynamicBorder());
-		this.ctx.chatContainer.addChild(block);
-		this.ctx.ui.requestRender();
+		this.ctx.present(block);
 	}
 
 	async handleMemoryCommand(text: string): Promise<void> {
@@ -483,8 +472,7 @@ export class CommandController {
 			block.addChild(new Spacer(1));
 			block.addChild(new Markdown(payload, 1, 1, getMarkdownTheme()));
 			block.addChild(new DynamicBorder());
-			this.ctx.chatContainer.addChild(block);
-			this.ctx.ui.requestRender();
+			this.ctx.present(block);
 			return;
 		}
 
@@ -805,8 +793,7 @@ export class CommandController {
 		this.ctx.streamingMessage = undefined;
 		this.ctx.pendingTools.clear();
 
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		this.ctx.chatContainer.addChild(new Text(`${theme.fg("accent", `${theme.status.success} ${label}`)}`, 1, 1));
+		this.ctx.present([new Spacer(1), new Text(`${theme.fg("accent", `${theme.status.success} ${label}`)}`, 1, 1)]);
 		await this.ctx.reloadTodos();
 		this.ctx.ui.requestRender(true, { clearScrollback: true });
 	}
@@ -845,11 +832,10 @@ export class CommandController {
 
 		const sessionFile = this.ctx.session.sessionFile;
 		const shortPath = sessionFile ? sessionFile.split("/").pop() : "new session";
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		this.ctx.chatContainer.addChild(
+		this.ctx.present([
+			new Spacer(1),
 			new Text(`${theme.fg("accent", `${theme.status.success} Session forked to ${shortPath}`)}`, 1, 1),
-		);
-		this.ctx.ui.requestRender();
+		]);
 	}
 
 	async handleMoveCommand(targetPath: string): Promise<void> {
@@ -883,11 +869,10 @@ export class CommandController {
 			await this.ctx.sessionManager.moveTo(resolvedPath);
 			await this.ctx.applyCwdChange(resolvedPath);
 
-			this.ctx.chatContainer.addChild(new Spacer(1));
-			this.ctx.chatContainer.addChild(
+			this.ctx.present([
+				new Spacer(1),
 				new Text(`${theme.fg("accent", `${theme.status.success} Session moved to ${resolvedPath}`)}`, 1, 1),
-			);
-			this.ctx.ui.requestRender();
+			]);
 		} catch (err) {
 			this.ctx.showError(`Move failed: ${err instanceof Error ? err.message : String(err)}`);
 		}
@@ -918,7 +903,7 @@ export class CommandController {
 			this.ctx.pendingMessagesContainer.addChild(this.ctx.bashComponent);
 			this.ctx.pendingBashComponents.push(this.ctx.bashComponent);
 		} else {
-			this.ctx.chatContainer.addChild(this.ctx.bashComponent);
+			this.ctx.present(this.ctx.bashComponent);
 		}
 		this.ctx.ui.requestRender();
 
@@ -959,7 +944,7 @@ export class CommandController {
 			this.ctx.pendingMessagesContainer.addChild(this.ctx.pythonComponent);
 			this.ctx.pendingPythonComponents.push(this.ctx.pythonComponent);
 		} else {
-			this.ctx.chatContainer.addChild(this.ctx.pythonComponent);
+			this.ctx.present(this.ctx.pythonComponent);
 		}
 		this.ctx.ui.requestRender();
 
@@ -1148,10 +1133,10 @@ export class CommandController {
 			this.ctx.updateEditorBorderColor();
 			await this.ctx.reloadTodos();
 
-			this.ctx.chatContainer.addChild(new Spacer(1));
-			this.ctx.chatContainer.addChild(
+			this.ctx.present([
+				new Spacer(1),
 				new Text(`${theme.fg("accent", `${theme.status.success} New session started with handoff context`)}`, 1, 1),
-			);
+			]);
 			if (result.savedPath) {
 				this.ctx.showStatus(`Handoff document saved to: ${result.savedPath}`);
 			}
diff --git a/packages/coding-agent/src/modes/controllers/event-controller.ts b/packages/coding-agent/src/modes/controllers/event-controller.ts
index 66497e783..bdaeab4ec 100644
--- a/packages/coding-agent/src/modes/controllers/event-controller.ts
+++ b/packages/coding-agent/src/modes/controllers/event-controller.ts
@@ -830,14 +830,12 @@ export class EventController {
 	async #handleTtsrTriggered(event: Extract<AgentSessionEvent, { type: "ttsr_triggered" }>): Promise<void> {
 		const component = new TtsrNotificationComponent(event.rules);
 		component.setExpanded(this.ctx.toolOutputExpanded);
-		this.ctx.chatContainer.addChild(component);
-		this.ctx.ui.requestRender();
+		this.ctx.present(component);
 	}
 
 	async #handleTodoReminder(event: Extract<AgentSessionEvent, { type: "todo_reminder" }>): Promise<void> {
 		const component = new TodoReminderComponent(event.todos, event.attempt, event.maxAttempts);
-		this.ctx.chatContainer.addChild(component);
-		this.ctx.ui.requestRender();
+		this.ctx.present(component);
 	}
 
 	async #handleTodoAutoClear(_event: Extract<AgentSessionEvent, { type: "todo_auto_clear" }>): Promise<void> {
diff --git a/packages/coding-agent/src/modes/controllers/extension-ui-controller.ts b/packages/coding-agent/src/modes/controllers/extension-ui-controller.ts
index e2b994fce..8f09b645b 100644
--- a/packages/coding-agent/src/modes/controllers/extension-ui-controller.ts
+++ b/packages/coding-agent/src/modes/controllers/extension-ui-controller.ts
@@ -176,10 +176,10 @@ export class ExtensionUiController {
 				this.ctx.streamingMessage = undefined;
 				this.ctx.pendingTools.clear();
 
-				this.ctx.chatContainer.addChild(new Spacer(1));
-				this.ctx.chatContainer.addChild(
+				this.ctx.present([
+					new Spacer(1),
 					new Text(`${theme.fg("accent", `${theme.status.success} New session started`)}`, 1, 1),
-				);
+				]);
 				await this.ctx.reloadTodos();
 				this.ctx.ui.requestRender(true, { clearScrollback: true });
 
@@ -415,10 +415,10 @@ export class ExtensionUiController {
 				this.ctx.streamingMessage = undefined;
 				this.ctx.pendingTools.clear();
 
-				this.ctx.chatContainer.addChild(new Spacer(1));
-				this.ctx.chatContainer.addChild(
+				this.ctx.present([
+					new Spacer(1),
 					new Text(`${theme.fg("accent", `${theme.status.success} New session started`)}`, 1, 1),
-				);
+				]);
 				await this.ctx.reloadTodos();
 				this.ctx.ui.requestRender(true, { clearScrollback: true });
 
@@ -562,8 +562,7 @@ export class ExtensionUiController {
 			return;
 		}
 		const errorText = new Text(theme.fg("error", `Tool "${toolName}" error: ${error}`), 1, 0);
-		this.ctx.chatContainer.addChild(errorText);
-		this.ctx.ui.requestRender();
+		this.ctx.present(errorText);
 	}
 
 	/**
@@ -860,8 +859,7 @@ export class ExtensionUiController {
 
 	showExtensionError(extensionPath: string, error: string): void {
 		const errorText = new Text(theme.fg("error", `Extension "${extensionPath}" error: ${error}`), 1, 0);
-		this.ctx.chatContainer.addChild(errorText);
-		this.ctx.ui.requestRender();
+		this.ctx.present(errorText);
 	}
 	async #handleInteractiveCompact(instructionsOrOptions: string | CompactOptions | undefined): Promise<void> {
 		if (this.ctx.isBackgrounded) {
diff --git a/packages/coding-agent/src/modes/controllers/mcp-command-controller.ts b/packages/coding-agent/src/modes/controllers/mcp-command-controller.ts
index 86fb385af..c63e57162 100644
--- a/packages/coding-agent/src/modes/controllers/mcp-command-controller.ts
+++ b/packages/coding-agent/src/modes/controllers/mcp-command-controller.ts
@@ -37,6 +37,7 @@ import type { MCPAuthConfig, MCPServerConfig, MCPServerConnection } from "../../
 import type { OAuthCredential } from "../../session/auth-storage";
 import { shortenPath } from "../../tools/render-utils";
 import { openPath } from "../../utils/open";
+import { ChatBlock } from "../components/chat-block";
 import { MCPAddWizard } from "../components/mcp-add-wizard";
 import { TranscriptBlock } from "../components/transcript-container";
 import { parseCommandArgs } from "../shared";
@@ -50,6 +51,42 @@ function withTimeout<T>(promise: Promise<T>, timeoutMs: number, message: string)
 	return Promise.race([promise, timeoutPromise]).finally(() => clearTimeout(timer));
 }
 
+/**
+ * Animated "Connecting to …" transcript block. Owns its spinner interval: it
+ * starts on mount and is cleared on {@link ChatBlock.finish}/dispose, so callers
+ * never juggle `setInterval`/`clearInterval` or `requestRender` by hand.
+ */
+class McpConnectingBlock extends ChatBlock {
+	readonly #text: Text;
+
+	constructor(private readonly serverName: string) {
+		super();
+		this.addChild(new Spacer(1));
+		const frame = theme.spinnerFrames[0] ?? "|";
+		this.#text = new Text(theme.fg("muted", `${frame} Connecting to "${serverName}"...`), 1, 0);
+		this.addChild(this.#text);
+	}
+
+	protected override onMount(): void {
+		const frames = theme.spinnerFrames;
+		let frame = 0;
+		const interval = setInterval(() => {
+			frame++;
+			this.#text.setText(
+				theme.fg("muted", `${frames[frame % frames.length] ?? "|"} Connecting to "${this.serverName}"...`),
+			);
+			this.requestRender();
+		}, 80);
+		this.onCleanup(() => clearInterval(interval));
+	}
+
+	/** Replace the spinner line with a terminal status; pair with {@link finish}. */
+	setStatus(text: string): void {
+		this.#text.setText(text);
+		this.requestRender();
+	}
+}
+
 /**
  * Outcome of {@link MCPCommandController}'s OAuth handler.
  *
@@ -550,7 +587,7 @@ export class MCPCommandController {
 					onAuth: (info: { url: string; instructions?: string }) => {
 						// Show auth URL prominently in chat as one block
 						const block = new TranscriptBlock();
-						this.ctx.chatContainer.addChild(block);
+						this.ctx.present(block);
 						block.addChild(new Text(theme.fg("accent", "━━━ OAuth Authorization Required ━━━"), 1, 0));
 						block.addChild(new Spacer(1));
 						block.addChild(new Text(theme.fg("muted", "Preparing browser authorization..."), 1, 0));
@@ -564,7 +601,6 @@ export class MCPCommandController {
 						);
 						block.addChild(new Spacer(1));
 						block.addChild(new Text(theme.fg("accent", "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"), 1, 0));
-						this.ctx.ui.requestRender();
 						// Try to open browser automatically
 						try {
 							openPath(info.url);
@@ -587,9 +623,7 @@ export class MCPCommandController {
 						}
 					},
 					onProgress: (message: string) => {
-						this.ctx.chatContainer.addChild(new Spacer(1));
-						this.ctx.chatContainer.addChild(new Text(theme.fg("muted", message), 1, 0));
-						this.ctx.ui.requestRender();
+						this.ctx.present([new Spacer(1), new Text(theme.fg("muted", message), 1, 0)]);
 					},
 				},
 			);
@@ -597,9 +631,10 @@ export class MCPCommandController {
 			// Execute OAuth flow with 5 minute timeout
 			const credentials = await withTimeout(flow.login(), 5 * 60 * 1000, "OAuth flow timed out after 5 minutes");
 
-			this.ctx.chatContainer.addChild(new Spacer(1));
-			this.ctx.chatContainer.addChild(new Text(theme.fg("success", "✓ Authorization completed in browser."), 1, 0));
-			this.ctx.ui.requestRender();
+			this.ctx.present([
+				new Spacer(1),
+				new Text(theme.fg("success", "✓ Authorization completed in browser."), 1, 0),
+			]);
 
 			// Generate a unique credential ID
 			const credentialId = `mcp_oauth_${Date.now()}_${Math.random().toString(36).slice(2, 11)}`;
@@ -752,19 +787,8 @@ export class MCPCommandController {
 	): Promise<"connected" | "connecting" | "disconnected"> {
 		if (!this.ctx.mcpManager) return "disconnected";
 
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		const frames = theme.spinnerFrames;
-		const initialFrame = frames[0] ?? "|";
-		const statusText = new Text(theme.fg("muted", `${initialFrame} Connecting to "${name}"...`), 1, 0);
-		this.ctx.chatContainer.addChild(statusText);
-		this.ctx.ui.requestRender();
-
-		let frame = 0;
-		const interval = setInterval(() => {
-			statusText.setText(theme.fg("muted", `${frames[frame % frames.length]} Connecting to "${name}"...`));
-			frame++;
-			this.ctx.ui.requestRender();
-		}, 80);
+		const block = new McpConnectingBlock(name);
+		this.ctx.present(block);
 
 		try {
 			try {
@@ -778,20 +802,19 @@ export class MCPCommandController {
 				await this.ctx.session.refreshMCPTools(this.ctx.mcpManager.getTools());
 			}
 			if (state === "connected") {
-				statusText.setText(theme.fg("success", `✓ Connected to "${name}"`));
+				block.setStatus(theme.fg("success", `✓ Connected to "${name}"`));
 			} else if (state === "connecting") {
-				statusText.setText(theme.fg("muted", `◌ "${name}" is still connecting...`));
+				block.setStatus(theme.fg("muted", `◌ "${name}" is still connecting...`));
 			} else {
-				statusText.setText(
+				block.setStatus(
 					options?.suppressDisconnectedWarning
 						? theme.fg("muted", `◌ Connection check complete for "${name}"`)
 						: theme.fg("warning", `⚠ Could not connect to "${name}" yet`),
 				);
 			}
-			this.ctx.ui.requestRender();
 			return state;
 		} finally {
-			clearInterval(interval);
+			block.finish();
 		}
 	}
 
diff --git a/packages/coding-agent/src/modes/controllers/selector-controller.ts b/packages/coding-agent/src/modes/controllers/selector-controller.ts
index 7aa831822..2d2728db2 100644
--- a/packages/coding-agent/src/modes/controllers/selector-controller.ts
+++ b/packages/coding-agent/src/modes/controllers/selector-controller.ts
@@ -933,7 +933,6 @@ export class SelectorController {
 			await this.ctx.session.modelRegistry.authStorage.login(providerId as OAuthProvider, {
 				onAuth: (info: { url: string; instructions?: string }) => {
 					const block = new TranscriptBlock();
-					this.ctx.chatContainer.addChild(block);
 					block.addChild(new Text(theme.fg("dim", info.url), 1, 0));
 					const hyperlink = `\x1b]8;;${info.url}\x07Click here to login\x1b]8;;\x07`;
 					block.addChild(new Text(theme.fg("accent", hyperlink), 1, 0));
@@ -945,17 +944,16 @@ export class SelectorController {
 						block.addChild(new Spacer(1));
 						block.addChild(new Text(theme.fg("dim", MANUAL_LOGIN_TIP), 1, 0));
 					}
-					this.ctx.ui.requestRender();
+					this.ctx.present(block);
 					this.ctx.openInBrowser(info.url);
 				},
 				onPrompt: async (prompt: { message: string; placeholder?: string }) => {
 					const promptBlock = new TranscriptBlock();
-					this.ctx.chatContainer.addChild(promptBlock);
 					promptBlock.addChild(new Text(theme.fg("warning", prompt.message), 1, 0));
 					if (prompt.placeholder) {
 						promptBlock.addChild(new Text(theme.fg("dim", prompt.placeholder), 1, 0));
 					}
-					this.ctx.ui.requestRender();
+					this.ctx.present(promptBlock);
 					const { promise, resolve } = Promise.withResolvers<string>();
 					const codeInput = new Input();
 					codeInput.onSubmit = () => {
@@ -972,8 +970,7 @@ export class SelectorController {
 					return promise;
 				},
 				onProgress: (message: string) => {
-					this.ctx.chatContainer.addChild(new Text(theme.fg("dim", message), 1, 0));
-					this.ctx.ui.requestRender();
+					this.ctx.present(new Text(theme.fg("dim", message), 1, 0));
 				},
 				onManualCodeInput: useManualInput ? () => manualInput.waitForInput(providerId) : undefined,
 			});
@@ -983,8 +980,7 @@ export class SelectorController {
 				new Text(theme.fg("success", `${theme.status.success} Successfully logged in to ${providerId}`), 1, 0),
 			);
 			block.addChild(new Text(theme.fg("dim", `Credentials saved to ${getAgentDbPath()}`), 1, 0));
-			this.ctx.chatContainer.addChild(block);
-			this.ctx.ui.requestRender();
+			this.ctx.present(block);
 		} catch (error: unknown) {
 			this.ctx.showError(`Login failed: ${error instanceof Error ? error.message : String(error)}`);
 		} finally {
@@ -1017,8 +1013,7 @@ export class SelectorController {
 					new Text(theme.fg("warning", `${providerId} is still authenticated via ${remainingSource}`), 1, 0),
 				);
 			}
-			this.ctx.chatContainer.addChild(block);
-			this.ctx.ui.requestRender();
+			this.ctx.present(block);
 		} catch (error: unknown) {
 			this.ctx.showError(`Logout failed: ${error instanceof Error ? error.message : String(error)}`);
 		}
diff --git a/packages/coding-agent/src/modes/interactive-mode.ts b/packages/coding-agent/src/modes/interactive-mode.ts
index 6abe5cb10..eb5b8b630 100644
--- a/packages/coding-agent/src/modes/interactive-mode.ts
+++ b/packages/coding-agent/src/modes/interactive-mode.ts
@@ -94,6 +94,7 @@ import { getSessionAccentAnsi, getSessionAccentHex } from "../utils/session-colo
 import { popTerminalTitle, pushTerminalTitle, setSessionTerminalTitle } from "../utils/title-generator";
 import type { AssistantMessageComponent } from "./components/assistant-message";
 import type { BashExecutionComponent } from "./components/bash-execution";
+import { ChatBlock, type ChatBlockHost } from "./components/chat-block";
 import { CustomEditor } from "./components/custom-editor";
 import { DynamicBorder } from "./components/dynamic-border";
 import { ErrorBannerComponent } from "./components/error-banner";
@@ -367,6 +368,7 @@ export class InteractiveMode implements InteractiveModeContext {
 	#eventBus?: EventBus;
 	#eventBusUnsubscribers: Array<() => void> = [];
 	#welcomeComponent?: WelcomeComponent;
+	readonly #chatHost: ChatBlockHost = { requestRender: () => this.ui.requestRender() };
 
 	constructor(
 		session: AgentSession,
@@ -2529,6 +2531,25 @@ export class InteractiveMode implements InteractiveModeContext {
 	}
 
 	// UI helpers
+	present(content: Component | readonly Component[]): void {
+		if (Array.isArray(content)) {
+			for (const item of content) this.#mountChatChild(item);
+		} else {
+			this.#mountChatChild(content as Component);
+		}
+		this.ui.requestRender();
+	}
+
+	#mountChatChild(item: Component): void {
+		this.chatContainer.addChild(item);
+		if (item instanceof ChatBlock) item.mount(this.#chatHost);
+	}
+
+	resetTranscript(): void {
+		this.chatContainer.dispose();
+		this.chatContainer.clear();
+	}
+
 	showStatus(message: string, options?: { dim?: boolean }): void {
 		this.#uiHelpers.showStatus(message, options);
 	}
diff --git a/packages/coding-agent/src/modes/types.ts b/packages/coding-agent/src/modes/types.ts
index de2cfa880..c49595d4e 100644
--- a/packages/coding-agent/src/modes/types.ts
+++ b/packages/coding-agent/src/modes/types.ts
@@ -158,6 +158,20 @@ export interface InteractiveModeContext {
 	handleBackgroundEvent(event: AgentSessionEvent): Promise<void>;
 
 	// UI helpers
+	/**
+	 * Mount transcript content and repaint once. The single sink for "show this in
+	 * chat": producers build and return a `Component` (or a `ChatBlock` carrying
+	 * its own lifecycle) and hand it here instead of touching `chatContainer` /
+	 * `ui.requestRender()` directly. `ChatBlock`s are mounted (their `onMount`
+	 * runs) so their timers/subscriptions start.
+	 */
+	present(content: Component | readonly Component[]): void;
+	/**
+	 * Dispose every live block in the transcript (stopping timers/subscriptions)
+	 * and clear it. Used before a full rebuild so animated/streaming blocks do not
+	 * leak.
+	 */
+	resetTranscript(): void;
 	showStatus(message: string, options?: { dim?: boolean }): void;
 	showError(message: string): void;
 	showPinnedError(message: string): void;
diff --git a/packages/coding-agent/src/modes/utils/ui-helpers.ts b/packages/coding-agent/src/modes/utils/ui-helpers.ts
index fca5bea57..140a43d4b 100644
--- a/packages/coding-agent/src/modes/utils/ui-helpers.ts
+++ b/packages/coding-agent/src/modes/utils/ui-helpers.ts
@@ -91,11 +91,9 @@ export class UiHelpers {
 
 		const spacer = new Spacer(1);
 		const text = new Text(rendered, 1, 0);
-		this.ctx.chatContainer.addChild(spacer);
-		this.ctx.chatContainer.addChild(text);
+		this.ctx.present([spacer, text]);
 		this.ctx.lastStatusSpacer = spacer;
 		this.ctx.lastStatusText = text;
-		this.ctx.ui.requestRender();
 	}
 
 	addMessageToChat(
@@ -492,8 +490,15 @@ export class UiHelpers {
 	renderInitialMessages(prebuiltContext?: SessionContext, options: RenderInitialMessagesOptions = {}): void {
 		// This path is used to rebuild the visible chat transcript (e.g. after custom/debug UI).
 		// Clear existing rendered chat first to avoid duplicating the full session in the container.
+		// On a non-preserving rebuild the existing blocks are discarded for good, so
+		// dispose them (stopping any live timers/subscriptions) before clearing. When
+		// preserving, the same instances are re-added below, so detach without dispose.
 		const preservedChatChildren = options.preserveExistingChat ? this.ctx.chatContainer.children : undefined;
-		this.ctx.chatContainer.clear();
+		if (preservedChatChildren) {
+			this.ctx.chatContainer.clear();
+		} else {
+			this.ctx.resetTranscript();
+		}
 		this.ctx.pendingMessagesContainer.clear();
 		this.ctx.pendingBashComponents = [];
 		this.ctx.pendingPythonComponents = [];
@@ -544,9 +549,7 @@ export class UiHelpers {
 			process.stderr.write(`Error: ${errorMessage}\n`);
 			return;
 		}
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		this.ctx.chatContainer.addChild(new Text(theme.fg("error", `Error: ${errorMessage}`), 1, 0));
-		this.ctx.ui.requestRender();
+		this.ctx.present([new Spacer(1), new Text(theme.fg("error", `Error: ${errorMessage}`), 1, 0)]);
 	}
 
 	showWarning(warningMessage: string): void {
@@ -554,9 +557,7 @@ export class UiHelpers {
 			process.stderr.write(`Warning: ${warningMessage}\n`);
 			return;
 		}
-		this.ctx.chatContainer.addChild(new Spacer(1));
-		this.ctx.chatContainer.addChild(new Text(theme.fg("warning", `Warning: ${warningMessage}`), 1, 0));
-		this.ctx.ui.requestRender();
+		this.ctx.present([new Spacer(1), new Text(theme.fg("warning", `Warning: ${warningMessage}`), 1, 0)]);
 	}
 
 	showNewVersionNotification(newVersion: string): void {
@@ -573,8 +574,7 @@ export class UiHelpers {
 			),
 		);
 		block.addChild(new DynamicBorder(text => theme.fg("warning", text)));
-		this.ctx.chatContainer.addChild(block);
-		this.ctx.ui.requestRender();
+		this.ctx.present(block);
 	}
 
 	updatePendingMessagesDisplay(): void {
diff --git a/packages/coding-agent/test/interactive-mode-status.test.ts b/packages/coding-agent/test/interactive-mode-status.test.ts
index 92bfc8987..aae1a575a 100644
--- a/packages/coding-agent/test/interactive-mode-status.test.ts
+++ b/packages/coding-agent/test/interactive-mode-status.test.ts
@@ -4,7 +4,7 @@ import { initTheme } from "@oh-my-pi/pi-coding-agent/modes/theme/theme";
 import type { InteractiveModeContext } from "@oh-my-pi/pi-coding-agent/modes/types";
 import { UiHelpers } from "@oh-my-pi/pi-coding-agent/modes/utils/ui-helpers";
 import { buildSessionContext, type SessionContext } from "@oh-my-pi/pi-coding-agent/session/session-manager";
-import { Container } from "@oh-my-pi/pi-tui";
+import { type Component, Container } from "@oh-my-pi/pi-tui";
 
 function renderLastLine(container: Container, width = 120): string {
 	const last = container.children[container.children.length - 1];
@@ -25,6 +25,11 @@ function createInitialRenderHarness(): { ctx: InteractiveModeContext; helpers: U
 		pendingPythonComponents: [],
 		pendingTools: new Map(),
 		ui: { requestRender: vi.fn() },
+		present: (content: Component | readonly Component[]) => {
+			const items = Array.isArray(content) ? content : [content];
+			for (const item of items) ctx.chatContainer.addChild(item);
+			ctx.ui.requestRender();
+		},
 		isBackgrounded: false,
 		sessionManager: {
 			buildSessionContext: () => buildSessionContext([]),
@@ -59,6 +64,11 @@ describe("InteractiveMode.showStatus", () => {
 		const ctx = {
 			chatContainer: new Container(),
 			ui: { requestRender: vi.fn() },
+			present: (content: Component | readonly Component[]) => {
+				const items = Array.isArray(content) ? content : [content];
+				for (const item of items) ctx.chatContainer.addChild(item);
+				ctx.ui.requestRender();
+			},
 			isBackgrounded: false,
 			lastStatusSpacer: undefined,
 			lastStatusText: undefined,
@@ -80,6 +90,11 @@ describe("InteractiveMode.showStatus", () => {
 		const ctx = {
 			chatContainer: new Container(),
 			ui: { requestRender: vi.fn() },
+			present: (content: Component | readonly Component[]) => {
+				const items = Array.isArray(content) ? content : [content];
+				for (const item of items) ctx.chatContainer.addChild(item);
+				ctx.ui.requestRender();
+			},
 			isBackgrounded: false,
 			lastStatusSpacer: undefined,
 			lastStatusText: undefined,
diff --git a/packages/coding-agent/test/issue-956-repro.test.ts b/packages/coding-agent/test/issue-956-repro.test.ts
index f7a1b38c7..1d1f4872b 100644
--- a/packages/coding-agent/test/issue-956-repro.test.ts
+++ b/packages/coding-agent/test/issue-956-repro.test.ts
@@ -80,6 +80,10 @@ describe("issue #956: interactive /mcp test", () => {
 		const disconnectServer = vi.spyOn(mcpClient, "disconnectServer").mockResolvedValue();
 		const controller = new MCPCommandController({
 			chatContainer: { addChild },
+			present: (content: unknown) => {
+				for (const item of Array.isArray(content) ? content : [content]) addChild(item);
+				requestRender();
+			},
 			ui: { requestRender },
 			editor: {},
 			showError,
diff --git a/packages/coding-agent/test/modes/components/chat-block.test.ts b/packages/coding-agent/test/modes/components/chat-block.test.ts
new file mode 100644
index 000000000..703504b9d
--- /dev/null
+++ b/packages/coding-agent/test/modes/components/chat-block.test.ts
@@ -0,0 +1,143 @@
+import { beforeEach, describe, expect, it } from "bun:test";
+import { ChatBlock, type ChatBlockHost } from "@oh-my-pi/pi-coding-agent/modes/components/chat-block";
+import type { Component } from "@oh-my-pi/pi-tui";
+
+/** Concrete subclass exposing the protected lifecycle seams for assertions. */
+class TestBlock extends ChatBlock {
+	mountCount = 0;
+	cleanupCount = 0;
+
+	protected override onMount(): void {
+		this.mountCount++;
+		this.onCleanup(() => {
+			this.cleanupCount++;
+		});
+	}
+
+	/** Public proxy for the protected requestRender. */
+	ping(): void {
+		this.requestRender();
+	}
+
+	/** Public proxy for the protected onCleanup. */
+	register(cleanup: () => void): void {
+		this.onCleanup(cleanup);
+	}
+}
+
+describe("ChatBlock lifecycle", () => {
+	let renders: number;
+	let host: ChatBlockHost;
+
+	beforeEach(() => {
+		renders = 0;
+		host = {
+			requestRender: () => {
+				renders++;
+			},
+		};
+	});
+
+	it("runs onMount exactly once; a second mount is a no-op", () => {
+		const block = new TestBlock();
+		expect(block.mountCount).toBe(0);
+		block.mount(host);
+		block.mount(host);
+		expect(block.mountCount).toBe(1);
+	});
+
+	it("is finalized until mounted, live while active, finalized after finish", () => {
+		const block = new TestBlock();
+		expect(block.isTranscriptBlockFinalized()).toBe(true);
+		block.mount(host);
+		expect(block.isTranscriptBlockFinalized()).toBe(false);
+		block.finish();
+		expect(block.isTranscriptBlockFinalized()).toBe(true);
+	});
+
+	it("finish runs cleanups once and requests one render", () => {
+		const block = new TestBlock();
+		block.mount(host);
+		const before = renders;
+		block.finish();
+		expect(block.cleanupCount).toBe(1);
+		expect(renders).toBe(before + 1);
+		block.finish();
+		expect(block.cleanupCount).toBe(1);
+	});
+
+	it("dispose runs cleanups once, is idempotent, and finalizes", () => {
+		const block = new TestBlock();
+		block.mount(host);
+		block.dispose();
+		expect(block.cleanupCount).toBe(1);
+		expect(block.isTranscriptBlockFinalized()).toBe(true);
+		block.dispose();
+		expect(block.cleanupCount).toBe(1);
+	});
+
+	it("finish then dispose does not double-run cleanups", () => {
+		const block = new TestBlock();
+		block.mount(host);
+		block.finish();
+		block.dispose();
+		expect(block.cleanupCount).toBe(1);
+	});
+
+	it("requestRender routes to the host only between mount and dispose", () => {
+		const block = new TestBlock();
+		block.ping();
+		expect(renders).toBe(0);
+		block.mount(host);
+		block.ping();
+		expect(renders).toBe(1);
+		block.dispose();
+		const after = renders;
+		block.ping();
+		expect(renders).toBe(after);
+	});
+
+	it("onCleanup registered after dispose runs immediately so callers never leak", () => {
+		const block = new TestBlock();
+		block.mount(host);
+		block.dispose();
+		let ran = false;
+		block.register(() => {
+			ran = true;
+		});
+		expect(ran).toBe(true);
+	});
+
+	it("dispose propagates to child components", () => {
+		const block = new TestBlock();
+		let childDisposed = 0;
+		const child: Component = {
+			render: () => [],
+			invalidate: () => {},
+			dispose: () => {
+				childDisposed++;
+			},
+		};
+		block.addChild(child);
+		block.mount(host);
+		block.dispose();
+		expect(childDisposed).toBe(1);
+	});
+
+	it("tears down a timer effect started in onMount when finished", async () => {
+		class TimerBlock extends ChatBlock {
+			protected override onMount(): void {
+				const id = setInterval(() => this.requestRender(), 5);
+				this.onCleanup(() => clearInterval(id));
+			}
+		}
+		const block = new TimerBlock();
+		block.mount(host);
+		await Bun.sleep(25);
+		expect(renders).toBeGreaterThan(0); // timer fired while active
+		block.finish();
+		const settled = renders; // includes finish()'s own render
+		await Bun.sleep(25);
+		expect(renders).toBe(settled); // interval torn down — no further ticks
+	});
+});
diff --git a/packages/coding-agent/test/modes/utils/render-initial-messages-dedupe.test.ts b/packages/coding-agent/test/modes/utils/render-initial-messages-dedupe.test.ts
index be1d43af3..52de0a13e 100644
--- a/packages/coding-agent/test/modes/utils/render-initial-messages-dedupe.test.ts
+++ b/packages/coding-agent/test/modes/utils/render-initial-messages-dedupe.test.ts
@@ -65,6 +65,7 @@ function makeCtx(sessionManager?: Pick<SessionManager, "buildSessionContext" | "
 		renderSessionContext: renderSessionContextSpy,
 		showStatus: vi.fn(),
 		ui: { requestRender: vi.fn() },
+		resetTranscript: () => ctx.chatContainer.clear(),
 	} as unknown as InteractiveModeContext;
 
 	return { ctx, buildSessionContextSpy, renderSessionContextSpy };
diff --git a/packages/coding-agent/test/tools/render-utils.test.ts b/packages/coding-agent/test/tools/render-utils.test.ts
index db3eb865f..f1c32d99c 100644
--- a/packages/coding-agent/test/tools/render-utils.test.ts
+++ b/packages/coding-agent/test/tools/render-utils.test.ts
@@ -2,7 +2,7 @@ import { afterEach, beforeAll, beforeEach, describe, expect, it } from "bun:test
 import * as os from "node:os";
 import * as path from "node:path";
 import { KeybindingsManager } from "@oh-my-pi/pi-coding-agent/config/keybindings";
-import { getThemeByName, initTheme, theme, type Theme } from "@oh-my-pi/pi-coding-agent/modes/theme/theme";
+import { getThemeByName, initTheme, type Theme, theme } from "@oh-my-pi/pi-coding-agent/modes/theme/theme";
 import {
 	dedupeParseErrors,
 	expandKeyHint,
@@ -14,7 +14,7 @@ import {
 	formatScreenshot,
 	truncateDiffByHunk,
 } from "@oh-my-pi/pi-coding-agent/tools/render-utils";
-import { getKeybindings, setKeybindings } from "@oh-my-pi/pi-tui";
+import { getKeybindings, setKeybindings, type KeybindingsManager as TuiKeybindingsManager } from "@oh-my-pi/pi-tui";
 
 describe("parse error formatting", () => {
 	it("deduplicates parse errors while preserving order", () => {
@@ -295,7 +295,7 @@ describe("formatExpandHint / expandKeyHint", () => {
 		format: { bracketLeft: "[", bracketRight: "]" },
 	} as unknown as Theme;
 
-	let previous: ReturnType<typeof getKeybindings>;
+	let previous: TuiKeybindingsManager;
 	beforeEach(() => {
 		previous = getKeybindings();
 	});
diff --git a/packages/tui/CHANGELOG.md b/packages/tui/CHANGELOG.md
index d864ad9ba..412067f39 100644
--- a/packages/tui/CHANGELOG.md
+++ b/packages/tui/CHANGELOG.md
@@ -1,6 +1,11 @@
 # Changelog
 
 ## [Unreleased]
+### Added
+
+- Added an optional `dispose()` lifecycle method to `Component` so components can release timers and subscriptions during permanent teardown
+- Added `Container.dispose()` to propagate teardown to child components when a component tree is permanently discarded
+- Added `Loader.dispose()` to stop the loader animation timer when the component is disposed
 
 ## [15.10.0] - 2026-06-06
 
diff --git a/packages/tui/src/components/loader.ts b/packages/tui/src/components/loader.ts
index b9b2ffca9..5f0393a77 100644
--- a/packages/tui/src/components/loader.ts
+++ b/packages/tui/src/components/loader.ts
@@ -71,6 +71,11 @@ export class Loader extends Text {
 		}
 	}
 
+	/** Lifecycle teardown: stop the animation timer. Idempotent. */
+	dispose() {
+		this.stop();
+	}
+
 	setMessage(message: string) {
 		this.message = message;
 		this.#updateDisplay();
diff --git a/packages/tui/src/tui.ts b/packages/tui/src/tui.ts
index 62db855a2..4b35fc3d5 100644
--- a/packages/tui/src/tui.ts
+++ b/packages/tui/src/tui.ts
@@ -128,6 +128,14 @@ export interface Component {
 	 * Called when theme changes or when component needs to re-render from scratch.
 	 */
 	invalidate(): void;
+
+	/**
+	 * Optional teardown. Called when the component is permanently removed from
+	 * the live tree (e.g. a transcript reset). Release timers, intervals, and
+	 * subscriptions here. Must be idempotent. Containers propagate dispose to
+	 * their children; leaf components without resources may omit it.
+	 */
+	dispose?(): void;
 }
 
 /**
@@ -339,6 +347,17 @@ export class Container implements Component {
 		}
 	}
 
+	/**
+	 * Propagate teardown to children. Call when the container's children are
+	 * being permanently discarded (not when they are detached for reuse — use
+	 * {@link clear} for that). Idempotent per child via each child's own dispose.
+	 */
+	dispose(): void {
+		for (const child of this.children) {
+			child.dispose?.();
+		}
+	}
+
 	render(width: number): string[] {
 		width = Math.max(1, width);
 		const lines: string[] = [];
diff --git a/packages/tui/test/container-dispose.test.ts b/packages/tui/test/container-dispose.test.ts
new file mode 100644
index 000000000..7c497a2f6
--- /dev/null
+++ b/packages/tui/test/container-dispose.test.ts
@@ -0,0 +1,30 @@
+import { describe, expect, it } from "bun:test";
+import { type Component, Container } from "@oh-my-pi/pi-tui";
+
+function inert(dispose?: () => void): Component {
+	return { render: () => [], invalidate: () => {}, dispose };
+}
+
+describe("Container.dispose", () => {
+	it("calls dispose on each child and tolerates children without dispose", () => {
+		const order: string[] = [];
+		const container = new Container();
+		container.addChild(inert(() => order.push("a")));
+		container.addChild(inert()); // no dispose — must not throw
+		container.addChild(inert(() => order.push("c")));
+
+		expect(() => container.dispose()).not.toThrow();
+		expect(order).toEqual(["a", "c"]);
+	});
+
+	it("recurses through nested containers", () => {
+		let leafDisposed = 0;
+		const outer = new Container();
+		const inner = new Container();
+		inner.addChild(inert(() => leafDisposed++));
+		outer.addChild(inner);
+
+		outer.dispose();
+		expect(leafDisposed).toBe(1);
+	});
+});
diff --git a/packages/tui/test/loader.test.ts b/packages/tui/test/loader.test.ts
index 06b35dcfa..7081d68ca 100644
--- a/packages/tui/test/loader.test.ts
+++ b/packages/tui/test/loader.test.ts
@@ -1,4 +1,4 @@
-import { describe, expect, it } from "bun:test";
+import { describe, expect, it, spyOn } from "bun:test";
 import { TUI } from "@oh-my-pi/pi-tui";
 import { Loader } from "@oh-my-pi/pi-tui/components/loader";
 import { visibleWidth } from "@oh-my-pi/pi-tui/utils";
@@ -28,4 +28,23 @@ describe("Loader component", () => {
 		loader.stop();
 		tui.stop();
 	});
+
+	it("dispose() stops the animation so no further renders are scheduled", async () => {
+		const term = new VirtualTerminal(20, 4);
+		const tui = new TUI(term);
+		const loader = new Loader(
+			tui,
+			text => text,
+			text => text,
+			"Checking",
+			["a", "b", "c"],
+		);
+		const spy = spyOn(tui, "requestRender");
+		loader.dispose();
+		const after = spy.mock.calls.length;
+		await Bun.sleep(40); // longer than the spinner interval
+		expect(spy.mock.calls.length).toBe(after);
+		expect(() => loader.dispose()).not.toThrow(); // idempotent
+		tui.stop();
+	});
 });