fix: kv_transfer_config is dataclass not json, fix for env var

src/engine_args.py

@@ -1,3 +1,4 @@
+import ast
 import os
 import json
 import logging
@@ -113,6 +114,17 @@ def _convert_env_value_to_field_type(value: str, field_name: str, field_type: ty
         except (json.JSONDecodeError, TypeError):
             pass
         return tuple(elem_type(x.strip()) for x in str(val).split(",") if x.strip())
+    # For dataclass/complex types, try JSON then Python literal parsing to dict
+    try:
+        return json.loads(val)
+    except (json.JSONDecodeError, TypeError):
+        pass
+    try:
+        parsed = ast.literal_eval(val)
+        if isinstance(parsed, (dict, list)):
+            return parsed
+    except (ValueError, SyntaxError):
+        pass
     # Fallback: try int, float, then str
     try:
         return int(val)
@@ -404,19 +416,35 @@ def get_engine_args():
     # LMCache requires HMA to be disabled
     try:
         _kv_transfer = args.get("kv_transfer_config")
+        if isinstance(_kv_transfer, str):
+            parsed = None
+            try:
+                parsed = json.loads(_kv_transfer)
+            except (json.JSONDecodeError, TypeError):
+                pass
+            if parsed is None:
+                try:
+                    result = ast.literal_eval(_kv_transfer)
+                    if isinstance(result, dict):
+                        parsed = result
+                except (ValueError, SyntaxError):
+                    pass
+            if parsed is not None:
+                _kv_transfer = parsed
+                args["kv_transfer_config"] = _kv_transfer
         _kv_offload = args.get("kv_offloading_backend")
 
-        lmcache_detected = _kv_offload == "lmcache" or (
+        lmcache_via_offload = _kv_offload == "lmcache"
+        lmcache_via_transfer = (
             isinstance(_kv_transfer, dict)
             and isinstance(_kv_transfer.get("kv_connector"), str)
             and "lmcache" in _kv_transfer.get("kv_connector", "").lower()
         )
+        lmcache_detected = lmcache_via_offload or lmcache_via_transfer
 
         if lmcache_detected and not args.get("disable_hybrid_kv_cache_manager"):
             args["disable_hybrid_kv_cache_manager"] = True
-            args["kv_offloading_backend"] = None
-            args["kv_transfer_config"] = None
-            logging.info("LMCache detected: automatically setting disable_hybrid_kv_cache_manager=True and clearing conflicting settings")
+            logging.info("LMCache detected: automatically setting disable_hybrid_kv_cache_manager=True")
         elif lmcache_detected and args.get("disable_hybrid_kv_cache_manager") is False:
             logging.warning(
                 "LMCache configuration detected but disabled: "