fix(tui): avoid duplicate VS Code right-click paste

closes #8186

packages/coding-agent/CHANGELOG.md

@@ -7,6 +7,7 @@
 - Fixed `pi.registerFlag()` accepting default values that do not match the declared flag type ([#8064](https://github.com/earendil-works/pi/issues/8064)).
 - Fixed Z.AI Coding Plan defaults referencing the removed GLM-5.1 model ([#8096](https://github.com/earendil-works/pi/issues/8096)).
 - Fixed repeated ambiguous truncated-response recovery being mislabeled as context overflow ([#8130](https://github.com/earendil-works/pi/issues/8130)).
+- Fixed duplicate fullscreen right-click paste in VS Code-based terminals on Windows ([#8186](https://github.com/earendil-works/pi/issues/8186)).
 
 ## [0.84.2] - 2026-08-14
 

packages/tui/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed duplicate fullscreen right-click paste in VS Code-based terminals on Windows ([#8186](https://github.com/earendil-works/pi/issues/8186)).
+
 ## [0.84.2] - 2026-08-14
 
 ### Added

packages/tui/src/tui-alt-screen.ts

@@ -695,7 +695,13 @@ export class TuiAltScreen extends TuiBase implements ViewportTUI {
 	}
 
 	private handleRightClickPaste(event: SgrMouseEvent): boolean {
-		if (!this.onRightClickPaste || process.platform !== "win32" || event.release || event.button !== 2) {
+		if (
+			!this.onRightClickPaste ||
+			process.platform !== "win32" ||
+			process.env.TERM_PROGRAM?.toLowerCase() === "vscode" ||
+			event.release ||
+			event.button !== 2
+		) {
 			return false;
 		}
 		try {

packages/tui/test/tui-alt-screen.test.ts

@@ -225,8 +225,9 @@ describe("TuiAltScreen", () => {
 		}
 	});
 
-	it("invokes the right-click paste handler only on Windows", () => {
+	it("invokes the right-click paste handler only on Windows outside VS Code", () => {
 		const platformDescriptor = Object.getOwnPropertyDescriptor(process, "platform");
+		const termProgram = process.env.TERM_PROGRAM;
 		assert.ok(platformDescriptor);
 		const terminal = new VirtualTerminal();
 		let pasteCount = 0;
@@ -237,17 +238,25 @@ describe("TuiAltScreen", () => {
 		});
 		try {
 			Object.defineProperty(process, "platform", { configurable: true, value: "win32" });
+			delete process.env.TERM_PROGRAM;
 			tui.start();
 			terminal.sendInput("\x1b[<2;1;1M");
 			terminal.sendInput("\x1b[<2;1;1m");
 			assert.strictEqual(pasteCount, 1);
 
+			process.env.TERM_PROGRAM = "vscode";
+			terminal.sendInput("\x1b[<2;1;1M");
+			assert.strictEqual(pasteCount, 1);
+
 			Object.defineProperty(process, "platform", { configurable: true, value: "linux" });
+			delete process.env.TERM_PROGRAM;
 			terminal.sendInput("\x1b[<2;1;1M");
 			assert.strictEqual(pasteCount, 1);
 		} finally {
 			tui.stop();
 			Object.defineProperty(process, "platform", platformDescriptor);
+			if (termProgram === undefined) delete process.env.TERM_PROGRAM;
+			else process.env.TERM_PROGRAM = termProgram;
 		}
 	});