diff --git a/sdk/guides/agent-server/api-sandbox.mdx b/sdk/guides/agent-server/api-sandbox.mdx
index fbe28bcb3..2fea0916e 100644
--- a/sdk/guides/agent-server/api-sandbox.mdx
+++ b/sdk/guides/agent-server/api-sandbox.mdx
@@ -5,6 +5,9 @@ description: Connect to hosted API-based agent server for fully managed infrastr
 
 > A ready-to-run example is available [here](#ready-to-run-example)!
 
+<Warning>
+The [Runtime API](https://runtime.all-hands.dev/) (`runtime.all-hands.dev`) is designed primarily for **[benchmark evaluation at scale](https://github.com/OpenHands/benchmarks)**, not for building production applications. If you are building a production application with the SDK, use the **[OpenHands Cloud Workspace](/sdk/guides/agent-server/cloud-workspace)** instead, which provides fully managed sandbox environments with SaaS credential support.
+</Warning>
 
 The API-sandboxed agent server demonstrates how to use `APIRemoteWorkspace` to connect to a [OpenHands runtime API service](https://runtime.all-hands.dev/). This eliminates the need to manage your own infrastructure, providing automatic scaling, monitoring, and secure sandboxed execution.