diff --git a/src/plugins/test-helpers/managed-npm-plugin.ts b/src/plugins/test-helpers/managed-npm-plugin.ts
new file mode 100644
index 00000000000..6a0d20e4c5c
--- /dev/null
+++ b/src/plugins/test-helpers/managed-npm-plugin.ts
@@ -0,0 +1,59 @@
+import fs from "node:fs";
+import path from "node:path";
+
+export function writeManagedNpmPlugin(params: {
+  stateDir: string;
+  packageName: string;
+  pluginId: string;
+  version: string;
+  name?: string;
+  dependencySpec?: string;
+}): string {
+  const npmRoot = path.join(params.stateDir, "npm");
+  const rootManifestPath = path.join(npmRoot, "package.json");
+  fs.mkdirSync(npmRoot, { recursive: true });
+  const rootManifest = fs.existsSync(rootManifestPath)
+    ? (JSON.parse(fs.readFileSync(rootManifestPath, "utf8")) as {
+        dependencies?: Record<string, string>;
+      })
+    : {};
+  fs.writeFileSync(
+    rootManifestPath,
+    JSON.stringify(
+      {
+        ...rootManifest,
+        private: true,
+        dependencies: {
+          ...rootManifest.dependencies,
+          [params.packageName]: params.dependencySpec ?? params.version,
+        },
+      },
+      null,
+      2,
+    ),
+    "utf8",
+  );
+
+  const packageDir = path.join(npmRoot, "node_modules", params.packageName);
+  fs.mkdirSync(path.join(packageDir, "dist"), { recursive: true });
+  fs.writeFileSync(
+    path.join(packageDir, "package.json"),
+    JSON.stringify({
+      name: params.packageName,
+      version: params.version,
+      openclaw: { extensions: ["./dist/index.js"] },
+    }),
+    "utf8",
+  );
+  fs.writeFileSync(
+    path.join(packageDir, "openclaw.plugin.json"),
+    JSON.stringify({
+      id: params.pluginId,
+      ...(params.name ? { name: params.name } : {}),
+      configSchema: { type: "object" },
+    }),
+    "utf8",
+  );
+  fs.writeFileSync(path.join(packageDir, "dist", "index.js"), "export {};\n", "utf8");
+  return packageDir;
+}