diff --git a/packages/coding-agent/src/modes/interactive/interactive-mode.ts b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
index 07fc5ea19..6d5e6b884 100644
--- a/packages/coding-agent/src/modes/interactive/interactive-mode.ts
+++ b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
@@ -352,6 +352,14 @@ export function createInteractiveTui(options: InteractiveTuiOptions): TuiMainScr
 			searchCurrentMatchStyle: (text) => theme.bold(theme.inverse(styleSearchMatch(text))),
 			openUrl: openBrowser,
 			onRightClickPaste: options.onRightClickPaste,
+			copySelection: async (text) => {
+				try {
+					await copyToClipboard(text);
+					return true;
+				} catch {
+					return false;
+				}
+			},
 		});
 	}
 	return new TuiMainScreen(terminal, options.showHardwareCursor, options.logDirectory);
diff --git a/packages/tui/src/tui-alt-screen.ts b/packages/tui/src/tui-alt-screen.ts
index 0dfc43c7f..783a92ab8 100644
--- a/packages/tui/src/tui-alt-screen.ts
+++ b/packages/tui/src/tui-alt-screen.ts
@@ -153,6 +153,11 @@ export interface TuiAltScreenOptions {
 	openUrl?: (url: string) => void;
 	/** Handle an unmodified secondary-button press for clipboard paste. Currently enabled on Windows only. */
 	onRightClickPaste?: () => void;
+	/**
+	 * Copy selected text to the system clipboard. Return `true` on success; the caller flashes
+	 * an error otherwise. When omitted, the selection is copied via an OSC 52 write.
+	 */
+	copySelection?: (text: string) => Promise<boolean>;
 }
 
 /** Alternate-screen TUI with a scrollable, application-owned viewport. */
@@ -192,6 +197,7 @@ export class TuiAltScreen extends TuiBase implements ViewportTUI {
 	private readonly searchCurrentMatchStyle: (text: string) => string;
 	private readonly openUrl?: (url: string) => void;
 	private readonly onRightClickPaste?: () => void;
+	private readonly copySelection?: (text: string) => Promise<boolean>;
 
 	constructor(
 		terminal: Terminal,
@@ -214,6 +220,7 @@ export class TuiAltScreen extends TuiBase implements ViewportTUI {
 		this.searchCurrentMatchStyle = options.searchCurrentMatchStyle ?? ((text) => `\x1b[1;7m${text}\x1b[22;27m`);
 		this.openUrl = options.openUrl;
 		this.onRightClickPaste = options.onRightClickPaste;
+		this.copySelection = options.copySelection;
 		this.addInputListener((data) => this.handleViewportInput(data));
 	}
 
@@ -971,7 +978,7 @@ export class TuiAltScreen extends TuiBase implements ViewportTUI {
 				this.requestRender();
 				return;
 			}
-			this.copySelectionToClipboard();
+			void this.copySelectionToClipboard();
 			this.requestRender();
 			return;
 		}
@@ -1047,7 +1054,7 @@ export class TuiAltScreen extends TuiBase implements ViewportTUI {
 		return { start: Math.max(minColumn, start), end: Math.min(maxColumn, end) };
 	}
 
-	private copySelectionToClipboard(): void {
+	private async copySelectionToClipboard(): Promise<void> {
 		const selection = this.getSelectionBounds();
 		if (!selection) return;
 		let sourceLines: readonly string[] = this.previousScreen;
@@ -1069,6 +1076,15 @@ export class TuiAltScreen extends TuiBase implements ViewportTUI {
 		}
 		const text = lines.join("\n");
 		if (text.length === 0) return;
+		// Prefer an injected clipboard implementation (native clipboard + platform tools with a
+		// verified success path) when the host app provides one. A bare OSC 52 write can show
+		// "Copied!" while leaving the system clipboard untouched (e.g. macOS Terminal.app, tmux
+		// without OSC 52 clipboard passthrough), so only report success when it actually copies.
+		if (this.copySelection) {
+			const ok = await this.copySelection(text);
+			this.flash(ok ? "Copied!" : "Copy failed");
+			return;
+		}
 		this.terminal.write(`\x1b]52;c;${Buffer.from(text).toString("base64")}\x07`);
 		this.flash("Copied!");
 	}
diff --git a/packages/tui/test/tui-alt-screen.test.ts b/packages/tui/test/tui-alt-screen.test.ts
index 1e0d94c22..2166debe7 100644
--- a/packages/tui/test/tui-alt-screen.test.ts
+++ b/packages/tui/test/tui-alt-screen.test.ts
@@ -963,6 +963,57 @@ describe("TuiAltScreen", () => {
 		tui.stop();
 	});
 
+	it("uses an injected copySelection handler instead of OSC 52 and reports success", async () => {
+		const terminal = new RecordingTerminal(20, 4);
+		const copied: string[] = [];
+		const tui = new TuiAltScreen(terminal, undefined, undefined, {
+			copySelection: async (text) => {
+				copied.push(text);
+				return true;
+			},
+		});
+		tui.addChild(new Text("alpha\nbeta\ngamma\ndelta", 0, 0));
+		tui.start();
+		await terminal.waitForRender();
+
+		terminal.sendInput("\x1b[<0;1;1M");
+		terminal.sendInput("\x1b[<32;4;2M");
+		terminal.sendInput("\x1b[<0;4;2m");
+		await terminal.waitForRender();
+
+		assert.deepStrictEqual(copied, ["alpha\nbeta"]);
+		assert.ok(
+			terminal.events.every((event) => event.type !== "write" || !event.data.includes("\x1b]52;c;")),
+			"must not emit OSC 52 when a copySelection handler is provided",
+		);
+		assert.ok(terminal.getViewport().some((line) => line.includes("Copied!")));
+
+		tui.stop();
+	});
+
+	it("flashes an error when the injected copySelection handler fails", async () => {
+		const terminal = new RecordingTerminal(20, 4);
+		const tui = new TuiAltScreen(terminal, undefined, undefined, {
+			copySelection: async () => false,
+		});
+		tui.addChild(new Text("alpha\nbeta\ngamma\ndelta", 0, 0));
+		tui.start();
+		await terminal.waitForRender();
+
+		terminal.sendInput("\x1b[<0;1;1M");
+		terminal.sendInput("\x1b[<32;4;2M");
+		terminal.sendInput("\x1b[<0;4;2m");
+		await terminal.waitForRender();
+
+		assert.ok(terminal.getViewport().some((line) => line.includes("Copy failed")));
+		assert.ok(
+			terminal.events.every((event) => event.type !== "write" || !event.data.includes("\x1b]52;c;")),
+			"must not emit OSC 52 when a copySelection handler is provided",
+		);
+
+		tui.stop();
+	});
+
 	it("does not append whitespace to double-click word highlighting", async () => {
 		const terminal = new RecordingTerminal(20, 1);
 		const tui = new TuiAltScreen(terminal);