Add option to suppress terminal responses

lib/interfaces.ts

@@ -22,6 +22,13 @@ export interface ITerminalOptions {
   // Scrolling options
   smoothScrollDuration?: number; // Duration in ms for smooth scroll animation (default: 100, 0 = instant)
 
+  // Emit terminal-generated responses through onData (default: true)
+  //
+  // Some host applications answer terminal queries at the PTY boundary instead
+  // of in the renderer. Disable this to keep parser-generated replies, such as
+  // DSR responses, out of the same stream as user keyboard input.
+  emitTerminalResponses?: boolean;
+
   // Internal: Ghostty WASM instance (optional, for test isolation)
   // If not provided, uses the module-level instance from init()
   ghostty?: Ghostty;

lib/terminal.test.ts

@@ -172,6 +172,34 @@ describe('Terminal', () => {
       disposable.dispose();
     });
 
+    test('emits terminal query responses through onData by default', async () => {
+      const term = await createIsolatedTerminal();
+      term.open(container!);
+
+      const receivedData: string[] = [];
+      term.onData((data) => receivedData.push(data));
+
+      term.write('\x1b[5n');
+
+      expect(receivedData).toContain('\x1b[0n');
+
+      term.dispose();
+    });
+
+    test('can keep terminal query responses out of onData', async () => {
+      const term = await createIsolatedTerminal({ emitTerminalResponses: false });
+      term.open(container!);
+
+      const receivedData: string[] = [];
+      term.onData((data) => receivedData.push(data));
+
+      term.write('\x1b[5n');
+
+      expect(receivedData).toEqual([]);
+
+      term.dispose();
+    });
+
     test('onResize fires when terminal is resized', async () => {
       const term = await createIsolatedTerminal({ cols: 80, rows: 24 });
       term.open(container!);

lib/terminal.ts

@@ -151,6 +151,7 @@ export class Terminal implements ITerminalCore {
       convertEol: options.convertEol ?? false,
       disableStdin: options.disableStdin ?? false,
       smoothScrollDuration: options.smoothScrollDuration ?? 100, // Default: 100ms smooth scroll
+      emitTerminalResponses: options.emitTerminalResponses ?? true,
     };
 
     // Wrap in Proxy to intercept runtime changes (xterm.js compatibility)
@@ -560,9 +561,12 @@ export class Terminal implements ITerminalCore {
     // Write directly to WASM terminal (handles VT parsing internally)
     this.wasmTerm!.write(data);
 
-    // Process any responses generated by the terminal (e.g., DSR cursor position)
-    // These need to be sent back to the PTY via onData
-    this.processTerminalResponses();
+    // Process any responses generated by the terminal (e.g., DSR cursor position).
+    // These are useful for direct browser PTY integrations, but embedders that
+    // answer terminal queries server-side can opt out to keep onData user-only.
+    if (this.options.emitTerminalResponses) {
+      this.processTerminalResponses();
+    }
 
     // Check for bell character (BEL, \x07)
     // WASM doesn't expose bell events, so we detect it in the data stream