diff --git a/browse/src/browser-manager.ts b/browse/src/browser-manager.ts
index 31a1f9def..c2f5574cb 100644
--- a/browse/src/browser-manager.ts
+++ b/browse/src/browser-manager.ts
@@ -62,7 +62,28 @@ export class BrowserManager {
   private consecutiveFailures: number = 0;
 
   async launch() {
-    this.browser = await chromium.launch({ headless: true });
+    // ─── Extension Support ────────────────────────────────────
+    // BROWSE_EXTENSIONS_DIR points to an unpacked Chrome extension directory.
+    // Extensions only work in headed mode, so we use an off-screen window.
+    const extensionsDir = process.env.BROWSE_EXTENSIONS_DIR;
+    const launchArgs: string[] = [];
+    let useHeadless = true;
+
+    if (extensionsDir) {
+      launchArgs.push(
+        `--disable-extensions-except=${extensionsDir}`,
+        `--load-extension=${extensionsDir}`,
+        '--window-position=-9999,-9999',
+        '--window-size=1,1',
+      );
+      useHeadless = false; // extensions require headed mode; off-screen window simulates headless
+      console.log(`[browse] Extensions loaded from: ${extensionsDir}`);
+    }
+
+    this.browser = await chromium.launch({
+      headless: useHeadless,
+      ...(launchArgs.length > 0 ? { args: launchArgs } : {}),
+    });
 
     // Chromium crash → exit with clear message
     this.browser.on('disconnected', () => {