diff --git a/ui/desktop/src/components/settings/extensions/deeplink.test.ts b/ui/desktop/src/components/settings/extensions/deeplink.test.ts
new file mode 100644
index 0000000000..92dde56010
--- /dev/null
+++ b/ui/desktop/src/components/settings/extensions/deeplink.test.ts
@@ -0,0 +1,88 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { addExtensionFromDeepLink } from './deeplink';
+
+vi.mock('../../../toasts', () => ({
+  toastService: {
+    handleError: vi.fn(),
+    success: vi.fn(),
+  },
+}));
+
+describe('addExtensionFromDeepLink', () => {
+  const mockAddExtension = vi.fn().mockResolvedValue(undefined);
+  const mockSetView = vi.fn();
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  describe('header parsing', () => {
+    it('should preserve = characters in header values', async () => {
+      const url =
+        'goose://extension?name=Remote&url=https%3A%2F%2Fexample.com%2Fmcp&header=Authorization%3DBasic%20abc%3D%3D';
+
+      await addExtensionFromDeepLink(url, mockAddExtension, mockSetView);
+
+      expect(mockSetView).toHaveBeenCalledWith(
+        'extensions',
+        expect.objectContaining({
+          showEnvVars: true,
+          deepLinkConfig: expect.objectContaining({
+            headers: { Authorization: 'Basic abc==' },
+          }),
+        })
+      );
+    });
+
+    it('should handle header values without = characters', async () => {
+      const url =
+        'goose://extension?name=Remote&url=https%3A%2F%2Fexample.com%2Fmcp&header=X-Token%3Dabc123';
+
+      await addExtensionFromDeepLink(url, mockAddExtension, mockSetView);
+
+      expect(mockSetView).toHaveBeenCalledWith(
+        'extensions',
+        expect.objectContaining({
+          deepLinkConfig: expect.objectContaining({
+            headers: { 'X-Token': 'abc123' },
+          }),
+        })
+      );
+    });
+
+    it('should handle multiple headers', async () => {
+      const url =
+        'goose://extension?name=Remote&url=https%3A%2F%2Fexample.com%2Fmcp&header=Authorization%3DBearer%20tok%3D%3D&header=X-Key%3Dval';
+
+      await addExtensionFromDeepLink(url, mockAddExtension, mockSetView);
+
+      expect(mockSetView).toHaveBeenCalledWith(
+        'extensions',
+        expect.objectContaining({
+          deepLinkConfig: expect.objectContaining({
+            headers: {
+              Authorization: 'Bearer tok==',
+              'X-Key': 'val',
+            },
+          }),
+        })
+      );
+    });
+
+    it('should handle header with empty value', async () => {
+      const url =
+        'goose://extension?name=Remote&url=https%3A%2F%2Fexample.com%2Fmcp&header=X-Empty%3D';
+
+      await addExtensionFromDeepLink(url, mockAddExtension, mockSetView);
+
+      expect(mockSetView).toHaveBeenCalledWith(
+        'extensions',
+        expect.objectContaining({
+          deepLinkConfig: expect.objectContaining({
+            headers: { 'X-Empty': '' },
+          }),
+        })
+      );
+    });
+  });
+});
diff --git a/ui/desktop/src/components/settings/extensions/deeplink.ts b/ui/desktop/src/components/settings/extensions/deeplink.ts
index adb321dd65..f8d59b40c6 100644
--- a/ui/desktop/src/components/settings/extensions/deeplink.ts
+++ b/ui/desktop/src/components/settings/extensions/deeplink.ts
@@ -141,8 +141,8 @@ export async function addExtensionFromDeepLink(
     headerParams.length > 0
       ? Object.fromEntries(
           headerParams.map((header) => {
-            const [key, value] = header.split('=');
-            return [key, decodeURIComponent(value || '')];
+            const [key, ...rest] = header.split('=');
+            return [key, decodeURIComponent(rest.join('=') || '')];
           })
         )
       : undefined;