diff --git a/scripts/e2e/lib/clawhub-fixture-server.cjs b/scripts/e2e/lib/clawhub-fixture-server.cjs
index f02ba6340e0..6a20cc1e4c1 100644
--- a/scripts/e2e/lib/clawhub-fixture-server.cjs
+++ b/scripts/e2e/lib/clawhub-fixture-server.cjs
@@ -17,12 +17,36 @@ const profiles = {
     packageJson: {
       name: packageName,
       version: "0.1.3",
+      type: "module",
+      dependencies: {
+        "is-number": "7.0.0",
+      },
+      peerDependencies: {
+        openclaw: ">=2026.4.11",
+      },
+      peerDependenciesMeta: {
+        openclaw: {
+          optional: true,
+        },
+      },
       openclaw: { extensions: ["./index.js"] },
     },
-    indexJs: `module.exports = {
+    indexJs: `import isNumber from "is-number";
+import { definePluginEntry } from "openclaw/plugin-sdk/plugin-entry";
+
+const dependencyUrl = import.meta.resolve("is-number");
+const expectedDependencyBaseUrl = new URL("./node_modules/is-number/", import.meta.url).href;
+if (!dependencyUrl.startsWith(expectedDependencyBaseUrl)) {
+  throw new Error(\`kitchen-sink dependency resolved outside plugin root: \${dependencyUrl}\`);
+}
+
+export default definePluginEntry({
   id: "${pluginId}",
   name: "OpenClaw Kitchen Sink",
   register(api) {
+    if (!isNumber(42)) {
+      throw new Error("kitchen-sink dependency sentinel did not load");
+    }
     api.registerProvider({
       id: "kitchen-sink-provider",
       label: "Kitchen Sink Provider",
@@ -48,7 +72,7 @@ const profiles = {
       },
     });
   },
-};
+});
 `,
     manifest: {
       id: pluginId,
diff --git a/scripts/e2e/lib/kitchen-sink-plugin/assertions.mjs b/scripts/e2e/lib/kitchen-sink-plugin/assertions.mjs
index e1018328bbe..336d7257f35 100644
--- a/scripts/e2e/lib/kitchen-sink-plugin/assertions.mjs
+++ b/scripts/e2e/lib/kitchen-sink-plugin/assertions.mjs
@@ -119,6 +119,38 @@ const expectIncludes = (listValue, expected, field) => {
   }
 };
 
+function assertRealPathInside(parentPath, childPath, label) {
+  const parentRealPath = fs.realpathSync(parentPath);
+  const childRealPath = fs.realpathSync(childPath);
+  if (
+    childRealPath !== parentRealPath &&
+    !childRealPath.startsWith(`${parentRealPath}${path.sep}`)
+  ) {
+    throw new Error(`${label} resolved outside ${parentPath}: ${childRealPath}`);
+  }
+}
+
+function assertClawHubExternalInstallContract(installPath) {
+  const openclawPeerPath = path.join(installPath, "node_modules", "openclaw");
+  if (!fs.existsSync(openclawPeerPath)) {
+    throw new Error(`missing kitchen-sink openclaw peer symlink: ${openclawPeerPath}`);
+  }
+  if (!fs.lstatSync(openclawPeerPath).isSymbolicLink()) {
+    throw new Error(`kitchen-sink openclaw peer is not a symlink: ${openclawPeerPath}`);
+  }
+  const hostRoot = fs.realpathSync(process.cwd());
+  const linkedHostRoot = fs.realpathSync(openclawPeerPath);
+  if (linkedHostRoot !== hostRoot) {
+    throw new Error(`expected kitchen-sink openclaw peer ${linkedHostRoot} to target ${hostRoot}`);
+  }
+
+  const dependencyPackagePath = path.join(installPath, "node_modules", "is-number", "package.json");
+  if (!fs.existsSync(dependencyPackagePath)) {
+    throw new Error(`missing kitchen-sink isolated dependency: ${dependencyPackagePath}`);
+  }
+  assertRealPathInside(installPath, dependencyPackagePath, "kitchen-sink isolated dependency");
+}
+
 function assertInstalled() {
   const pluginId = process.env.KITCHEN_SINK_ID;
   const spec = process.env.KITCHEN_SINK_SPEC;
@@ -270,6 +302,9 @@ function assertInstalled() {
   if (!fs.existsSync(installPath)) {
     throw new Error(`kitchen-sink install path missing: ${record.installPath}`);
   }
+  if (source === "clawhub") {
+    assertClawHubExternalInstallContract(installPath);
+  }
   fs.writeFileSync(`/tmp/kitchen-sink-${label}-install-path.txt`, installPath, "utf8");
 }
 
diff --git a/test/scripts/plugin-prerelease-test-plan.test.ts b/test/scripts/plugin-prerelease-test-plan.test.ts
index 771b760b8b4..1ea45b75b63 100644
--- a/test/scripts/plugin-prerelease-test-plan.test.ts
+++ b/test/scripts/plugin-prerelease-test-plan.test.ts
@@ -112,7 +112,11 @@ describe("scripts/lib/plugin-prerelease-test-plan.mjs", () => {
     expect(sweepScript).toContain("run_failure_scenario");
     expect(assertionsScript).toContain("record.source !== source");
     expect(assertionsScript).toContain("record.clawhubPackage !== packageName");
+    expect(assertionsScript).toContain("assertClawHubExternalInstallContract");
     expect(assertionsScript).toContain("expectedErrorMessages");
+    expect(readFileSync("scripts/e2e/lib/clawhub-fixture-server.cjs", "utf8")).toContain(
+      'from "openclaw/plugin-sdk/plugin-entry"',
+    );
     expect(script).toContain("docker stats --no-stream");
     expect(sweepScript).toContain("scan_logs_for_unexpected_errors");
   });