diff --git a/server/utils/AiProviders/openRouter/index.js b/server/utils/AiProviders/openRouter/index.js
index 28d4306b..9e3e5196 100644
--- a/server/utils/AiProviders/openRouter/index.js
+++ b/server/utils/AiProviders/openRouter/index.js
@@ -168,7 +168,7 @@ class OpenRouterLLM {
           {}
         )
       : {};
-    return availableModels[modelName]?.maxLength || 4096;
+    return availableModels[modelName]?.maxLength || Number(process.env.AGENT_CONTEXT_WINDOW_FALLBACK) || 2_000_000;
   }
 
   promptWindowLimit() {