Fix openai input_text type compatibility (#11935)

sgl-router/src/routers/openai/router.rs

@@ -749,6 +749,15 @@ impl crate::routers::RouterTrait for OpenAIRouter {
             ] {
                 obj.remove(key);
             }
+            // XAI (Grok models) requires special handling of input items
+            // Check if model is a Grok model
+            let is_grok_model = obj
+                .get("model")
+                .and_then(|v| v.as_str())
+                .map(|m| m.starts_with("grok"))
+                .unwrap_or(false);
+
+            if is_grok_model {
                 // XAI doesn't support the OPENAI item type input: https://platform.openai.com/docs/api-reference/responses/create#responses-create-input-input-item-list-item
                 // To Achieve XAI compatibility, strip extra fields from input messages (id, status)
                 // XAI doesn't support output_text as type for content with role of assistant
@@ -763,7 +772,9 @@ impl crate::routers::RouterTrait for OpenAIRouter {
                         if let Some(content_arr) =
                             item_obj.get_mut("content").and_then(Value::as_array_mut)
                         {
-                        for content_obj in content_arr.iter_mut().filter_map(Value::as_object_mut) {
+                            for content_obj in
+                                content_arr.iter_mut().filter_map(Value::as_object_mut)
+                            {
                                 // Change output_text to input_text
                                 if content_obj.get("type").and_then(Value::as_str)
                                     == Some("output_text")
@@ -778,6 +789,7 @@ impl crate::routers::RouterTrait for OpenAIRouter {
                     }
                 }
             }
+        }
 
         // Delegate to streaming or non-streaming handler
         if body.stream.unwrap_or(false) {