diff --git a/.changeset/bright-apes-begin.md b/.changeset/bright-apes-begin.md
new file mode 100644
index 0000000000..59a383449c
--- /dev/null
+++ b/.changeset/bright-apes-begin.md
@@ -0,0 +1,5 @@
+---
+"@lynx-js/web-elements": patch
+---
+
+Add scrollHeight/scrollWidth getters to XList.
diff --git a/.github/lynx-stack.instructions.md b/.github/lynx-stack.instructions.md
new file mode 100644
index 0000000000..54c8f0f100
--- /dev/null
+++ b/.github/lynx-stack.instructions.md
@@ -0,0 +1,5 @@
+---
+applyTo: "packages/web-platform/web-elements/**/*"
+---
+
+When updating web element APIs, add targeted Playwright tests in packages/web-platform/web-elements/tests/web-elements.spec.ts and keep changes minimal.
diff --git a/packages/web-platform/web-elements/src/elements/XList/XList.ts b/packages/web-platform/web-elements/src/elements/XList/XList.ts
index 234c70a4b4..ed84847c7f 100644
--- a/packages/web-platform/web-elements/src/elements/XList/XList.ts
+++ b/packages/web-platform/web-elements/src/elements/XList/XList.ts
@@ -46,6 +46,14 @@ export class XList extends HTMLElement {
     this.#getListContainer().scrollLeft = val;
   }
 
+  override get scrollHeight() {
+    return this.#getListContainer().scrollHeight;
+  }
+
+  override get scrollWidth() {
+    return this.#getListContainer().scrollWidth;
+  }
+
   get __scrollTop() {
     return super.scrollTop;
   }
diff --git a/packages/web-platform/web-elements/tests/web-elements.spec.ts b/packages/web-platform/web-elements/tests/web-elements.spec.ts
index 9de74f0fb8..4f4e0b668e 100644
--- a/packages/web-platform/web-elements/tests/web-elements.spec.ts
+++ b/packages/web-platform/web-elements/tests/web-elements.spec.ts
@@ -2141,11 +2141,19 @@ test.describe('web-elements test suite', () => {
             return (document.querySelector('x-list') as any)
               ?.getScrollContainerInfo();
           })).jsonValue();
+        const scrollHeight1 = await page.evaluate(() => {
+          return (document.querySelector('x-list') as any)?.scrollHeight;
+        });
+        const scrollWidth1 = await page.evaluate(() => {
+          return (document.querySelector('x-list') as any)?.scrollWidth;
+        });
         expect(
           typeof info1 === 'object' && info1.scrollLeft === 0
             && info1.scrollTop === 0 && info1.scrollHeight !== 0
             && info1.scrollWidth !== 0,
         ).toBeTruthy();
+        expect(scrollHeight1).toBe(info1.scrollHeight);
+        expect(scrollWidth1).toBe(info1.scrollWidth);
         await page.evaluate(() =>
           document.querySelector('x-list')?.shadowRoot?.querySelector(
             '#content',
@@ -2157,11 +2165,19 @@ test.describe('web-elements test suite', () => {
             return (document.querySelector('x-list') as any)
               ?.getScrollContainerInfo();
           })).jsonValue();
+        const scrollHeight2 = await page.evaluate(() => {
+          return (document.querySelector('x-list') as any)?.scrollHeight;
+        });
+        const scrollWidth2 = await page.evaluate(() => {
+          return (document.querySelector('x-list') as any)?.scrollWidth;
+        });
         expect(
           typeof info2 === 'object' && info2.scrollLeft === 200
             && info2.scrollTop === 200 && info2.scrollHeight !== 0
             && info2.scrollWidth !== 0,
         ).toBeTruthy();
+        expect(scrollHeight2).toBe(info2.scrollHeight);
+        expect(scrollWidth2).toBe(info2.scrollWidth);
       },
     );