diff --git a/sdk/arch/llm.mdx b/sdk/arch/llm.mdx
index 80a6d92da..c914674e9 100644
--- a/sdk/arch/llm.mdx
+++ b/sdk/arch/llm.mdx
@@ -299,6 +299,13 @@ flowchart TB
 
 ### LLM Providers
 
+The Agent Server's `/api/llm/models?provider=openrouter` endpoint includes the
+SDK's curated OpenRouter routes even when LiteLLM's catalog omits them. Returned
+identifiers keep the `openrouter/` prefix, such as
+`openrouter/deepseek/deepseek-chat`, so they can be passed directly to `LLM`.
+Additional models come from LiteLLM's catalog. The SDK resolves OpenRouter's
+runtime context limits through the provider's endpoints API.
+
 Provider integrations remain shared between the Software Agent SDK and the OpenHands Application.
 The pages linked below live under the OpenHands app section but apply
 verbatim to SDK applications because both layers wrap the same