diff --git a/src/engine_args.py b/src/engine_args.py
index 8105a09..0518f1b 100644
--- a/src/engine_args.py
+++ b/src/engine_args.py
@@ -13,6 +13,28 @@
     "MAX_CONTEXT_LEN_TO_CAPTURE": "max_seq_len_to_capture"
 }
 
+def parse_json_env_var(env_var_name, default=None):
+    """
+    Parse a JSON-formatted environment variable.
+
+    Args:
+        env_var_name (str): Name of the environment variable
+        default: Default value to return if env var is not set or invalid JSON
+
+    Returns:
+        Parsed JSON value (dict, list, str, int, float, bool, or None)
+    """
+    env_value = os.getenv(env_var_name, None)
+    if env_value is None:
+        return default
+
+    try:
+        return json.loads(env_value)
+    except json.JSONDecodeError as e:
+        logging.warning(f"Warning: Invalid JSON in {env_var_name}: {env_value}")
+        logging.warning(f"JSON Error: {e}")
+        return default
+
 DEFAULT_ARGS = {
     "disable_log_stats": os.getenv('DISABLE_LOG_STATS', 'False').lower() == 'true',
     "disable_log_requests": os.getenv('DISABLE_LOG_REQUESTS', 'False').lower() == 'true',
@@ -46,7 +68,7 @@
     "max_logprobs": int(os.getenv('MAX_LOGPROBS', 20)),  # Default value for OpenAI Chat Completions API
     "revision": os.getenv('REVISION', None),
     "code_revision": os.getenv('CODE_REVISION', None),
-    "rope_scaling": os.getenv('ROPE_SCALING', None),
+    "rope_scaling": parse_json_env_var('ROPE_SCALING'),
     "rope_theta": float(os.getenv('ROPE_THETA', 0)) or None,
     "tokenizer_revision": os.getenv('TOKENIZER_REVISION', None),
     "quantization": os.getenv('QUANTIZATION', None),
@@ -56,7 +78,7 @@
     "disable_custom_all_reduce": os.getenv('DISABLE_CUSTOM_ALL_REDUCE', 'False').lower() == 'true',
     "tokenizer_pool_size": int(os.getenv('TOKENIZER_POOL_SIZE', 0)),
     "tokenizer_pool_type": os.getenv('TOKENIZER_POOL_TYPE', 'ray'),
-    "tokenizer_pool_extra_config": os.getenv('TOKENIZER_POOL_EXTRA_CONFIG', None),
+    "tokenizer_pool_extra_config": parse_json_env_var('TOKENIZER_POOL_EXTRA_CONFIG'),
     "enable_lora": os.getenv('ENABLE_LORA', 'False').lower() == 'true',
     "max_loras": int(os.getenv('MAX_LORAS', 1)),
     "max_lora_rank": int(os.getenv('MAX_LORA_RANK', 16)),
@@ -72,7 +94,7 @@
     "ray_workers_use_nsight": os.getenv('RAY_WORKERS_USE_NSIGHT', 'False').lower() == 'true',
     "num_gpu_blocks_override": int(os.getenv('NUM_GPU_BLOCKS_OVERRIDE', 0)) or None,
     "num_lookahead_slots": int(os.getenv('NUM_LOOKAHEAD_SLOTS', 0)),
-    "model_loader_extra_config": os.getenv('MODEL_LOADER_EXTRA_CONFIG', None),
+    "model_loader_extra_config": parse_json_env_var('MODEL_LOADER_EXTRA_CONFIG'),
     "ignore_patterns": os.getenv('IGNORE_PATTERNS', None),
     "preemption_mode": os.getenv('PREEMPTION_MODE', None),
     "scheduler_delay_factor": float(os.getenv('SCHEDULER_DELAY_FACTOR', 0.0)),
@@ -136,25 +158,25 @@ def get_local_args():
 def get_engine_args():
     # Start with default args
     args = DEFAULT_ARGS
-    
+
     # Get env args that match keys in AsyncEngineArgs
     args.update(os.environ)
-    
+
     # Get local args if model is baked in and overwrite env args
     args.update(get_local_args())
-    
+
     # if args.get("TENSORIZER_URI"): TODO: add back once tensorizer is ready
     #     args["load_format"] = "tensorizer"
     #     args["model_loader_extra_config"] = TensorizerConfig(tensorizer_uri=args["TENSORIZER_URI"], num_readers=None)
     #     logging.info(f"Using tensorized model from {args['TENSORIZER_URI']}")
-    
-    
+
+
     # Rename and match to vllm args
     args = match_vllm_args(args)
 
     if args.get("load_format") == "bitsandbytes":
         args["quantization"] = args["load_format"]
-    
+
     # Set tensor parallel size and max parallel loading workers if more than 1 GPU is available
     num_gpus = device_count()
     if num_gpus > 1:
@@ -162,7 +184,7 @@ def get_engine_args():
         args["max_parallel_loading_workers"] = None
         if os.getenv("MAX_PARALLEL_LOADING_WORKERS"):
             logging.warning("Overriding MAX_PARALLEL_LOADING_WORKERS with None because more than 1 GPU is available.")
-    
+
     # Deprecated env args backwards compatibility
     if args.get("kv_cache_dtype") == "fp8_e5m2":
         args["kv_cache_dtype"] = "fp8"
@@ -170,9 +192,9 @@ def get_engine_args():
     if os.getenv("MAX_CONTEXT_LEN_TO_CAPTURE"):
         args["max_seq_len_to_capture"] = int(os.getenv("MAX_CONTEXT_LEN_TO_CAPTURE"))
         logging.warning("Using MAX_CONTEXT_LEN_TO_CAPTURE is deprecated. Please use MAX_SEQ_LEN_TO_CAPTURE instead.")
-        
+
     # if "gemma-2" in args.get("model", "").lower():
     #     os.environ["VLLM_ATTENTION_BACKEND"] = "FLASHINFER"
     #     logging.info("Using FLASHINFER for gemma-2 model.")
-        
+
     return AsyncEngineArgs(**args)