feat(hooks): expose setTitle to HookUIContext (#446)

packages/coding-agent/src/core/custom-tools/loader.ts

@@ -93,6 +93,7 @@ function createNoOpUIContext(): HookUIContext {
 		notify: () => {},
 		setStatus: () => {},
 		setWidget: () => {},
+		setTitle: () => {},
 		custom: async () => undefined as never,
 		setEditorText: () => {},
 		getEditorText: () => "",

packages/coding-agent/src/core/hooks/runner.ts

@@ -59,6 +59,7 @@ const noOpUIContext: HookUIContext = {
 	notify: () => {},
 	setStatus: () => {},
 	setWidget: () => {},
+	setTitle: () => {},
 	custom: async () => undefined as never,
 	setEditorText: () => {},
 	getEditorText: () => "",

packages/coding-agent/src/core/hooks/types.ts

@@ -120,6 +120,13 @@ export interface HookUIContext {
 	 */
 	setWidget(key: string, content: ((tui: TUI, theme: Theme) => Component & { dispose?(): void }) | undefined): void;
 
+	/**
+	 * Set the terminal window/tab title.
+	 * Uses OSC escape sequence (works in most modern terminals).
+	 * @param title - Title text to display
+	 */
+	setTitle(title: string): void;
+
 	/**
 	 * Show a custom component with keyboard focus.
 	 * The factory receives TUI, theme, and a done() callback to close the component.

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -685,6 +685,7 @@ export class InteractiveMode {
 			notify: (message, type) => this.showHookNotify(message, type),
 			setStatus: (key, text) => this.setHookStatus(key, text),
 			setWidget: (key, content) => this.setHookWidget(key, content),
+			setTitle: (title) => this.ui.terminal.setTitle(title),
 			custom: (factory) => this.showHookCustom(factory),
 			setEditorText: (text) => this.editor.setText(text),
 			getEditorText: () => this.editor.getText(),

packages/coding-agent/src/modes/rpc/rpc-mode.ts

@@ -145,6 +145,16 @@ export async function runRpcMode(session: AgentSession): Promise<never> {
 			// Component factories are not supported in RPC mode - would need TUI access
 		},
 
+		setTitle(title: string): void {
+			// Fire and forget - host can implement terminal title control
+			output({
+				type: "hook_ui_request",
+				id: crypto.randomUUID(),
+				method: "setTitle",
+				title,
+			} as RpcHookUIRequest);
+		},
+
 		async custom() {
 			// Custom UI not supported in RPC mode
 			return undefined as never;

packages/coding-agent/src/modes/rpc/rpc-types.ts

@@ -196,6 +196,7 @@ export type RpcHookUIRequest =
 			widgetKey: string;
 			widgetLines: string[] | undefined;
 	  }
+	| { type: "hook_ui_request"; id: string; method: "setTitle"; title: string }
 	| { type: "hook_ui_request"; id: string; method: "set_editor_text"; text: string };
 
 // ============================================================================