diff --git a/inference/convert.py b/inference/convert.py
index c606ce8..3277cea 100644
--- a/inference/convert.py
+++ b/inference/convert.py
@@ -1,14 +1,24 @@
 import os
 import shutil
+import logging
 from argparse import ArgumentParser
 from glob import glob
-from tqdm import tqdm, trange
+from pathlib import Path
+from typing import Dict, Tuple, List, Optional
 
+from tqdm import tqdm
 import torch
 from safetensors.torch import safe_open, save_file
 
+# Configure logging
+logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
+logger = logging.getLogger(__name__)
 
-mapping = {
+# Type aliases
+TensorMapping = Dict[str, Tuple[str, Optional[int]]]
+
+# Configuration mapping with type hints
+MAPPING: TensorMapping = {
     "embed_tokens": ("embed", 0),
     "input_layernorm": ("attn_norm", None),
     "post_attention_layernorm": ("ffn_norm", None),
@@ -29,68 +39,168 @@ mapping = {
     "scale": ("scale", None),
 }
 
+def validate_paths(hf_ckpt_path: str, save_path: str) -> None:
+    """Validate input and output paths."""
+    if not os.path.isdir(hf_ckpt_path):
+        raise ValueError(f"Input directory {hf_ckpt_path} does not exist")
+    
+    os.makedirs(save_path, exist_ok=True)
+    if not os.access(save_path, os.W_OK):
+        raise PermissionError(f"No write permission for output directory {save_path}")
 
-def main(hf_ckpt_path, save_path, n_experts, mp):
+def process_tensor_name(name: str) -> str:
+    """Process and normalize tensor names."""
+    # Remove 'model.' prefix if present
+    if name.startswith("model."):
+        name = name[len("model."):]
+    
+    # Replace specific patterns
+    replacements = {
+        "self_attn": "attn",
+        "mlp": "ffn",
+        "weight_scale_inv": "scale",
+        "e_score_correction_bias": "bias"
+    }
+    
+    for old, new in replacements.items():
+        name = name.replace(old, new)
+    
+    return name
+
+def split_tensor(param: torch.Tensor, dim: Optional[int], mp: int, idx: int) -> torch.Tensor:
+    """Split tensor for model parallelism."""
+    if dim is None:
+        return param
+    
+    if param.size(dim) % mp != 0:
+        raise ValueError(f"Dimension {dim} of tensor with shape {param.shape} "
+                         f"is not divisible by model parallelism factor {mp}")
+    
+    shard_size = param.size(dim) // mp
+    return param.narrow(dim, idx * shard_size, shard_size).contiguous()
+
+def process_checkpoint_files(
+    hf_ckpt_path: str,
+    mp: int,
+    n_local_experts: int,
+    state_dicts: List[Dict[str, torch.Tensor]]
+) -> None:
+    """Process all checkpoint files and populate state dictionaries."""
+    for file_path in tqdm(glob(os.path.join(hf_ckpt_path, "*.safetensors")), 
+                        desc="Processing checkpoint files"):
+        try:
+            with safe_open(file_path, framework="pt", device="cpu") as f:
+                for name in tqdm(f.keys(), desc=f"Processing {os.path.basename(file_path)}", leave=False):
+                    if "model.layers.61" in name:
+                        logger.debug(f"Skipping layer 61 tensor: {name}")
+                        continue
+                    
+                    param = f.get_tensor(name)
+                    processed_name = process_tensor_name(name)
+                    
+                    key = processed_name.split(".")[-2]
+                    if key not in MAPPING:
+                        raise KeyError(f"Unexpected tensor key: {key} in tensor {name}")
+                    
+                    new_key, dim = MAPPING[key]
+                    final_name = processed_name.replace(key, new_key)
+                    
+                    for i in range(mp):
+                        if "experts" in final_name and "shared_experts" not in final_name:
+                            expert_idx = int(final_name.split(".")[-3])
+                            if not (i * n_local_experts <= expert_idx < (i + 1) * n_local_experts):
+                                continue
+                        
+                        split_param = split_tensor(param, dim, mp, i)
+                        state_dicts[i][final_name] = split_param
+        except Exception as e:
+            logger.error(f"Error processing file {file_path}: {str(e)}")
+            raise
+
+def save_output_files(
+    state_dicts: List[Dict[str, torch.Tensor]],
+    save_path: str,
+    mp: int,
+    hf_ckpt_path: str
+) -> None:
+    """Save processed state dictionaries and copy token files."""
+    for i in tqdm(range(mp), desc="Saving output files"):
+        output_file = os.path.join(save_path, f"model{i}-mp{mp}.safetensors")
+        save_file(state_dicts[i], output_file, metadata={"format": "pt"})
+    
+    # Copy token-related files
+    for file_path in glob(os.path.join(hf_ckpt_path, "*token*")):
+        try:
+            shutil.copy(file_path, os.path.join(save_path, os.path.basename(file_path)))
+        except IOError as e:
+            logger.error(f"Error copying file {file_path}: {str(e)}")
+
+def main(
+    hf_ckpt_path: str,
+    save_path: str,
+    n_experts: int,
+    mp: int
+) -> None:
     """
-    Converts and saves model checkpoint files into a specified format.
-
+    Convert and split model checkpoints for distributed training.
+    
     Args:
-        hf_ckpt_path (str): Path to the directory containing the input checkpoint files.
-        save_path (str): Path to the directory where the converted checkpoint files will be saved.
-        n_experts (int): Total number of experts in the model.
-        mp (int): Model parallelism factor.
-        
-    Returns:
-        None
+        hf_ckpt_path: Path to HuggingFace format checkpoint directory
+        save_path: Output directory for converted checkpoints
+        n_experts: Total number of experts in the model
+        mp: Model parallelism factor
     """
     torch.set_num_threads(8)
+    validate_paths(hf_ckpt_path, save_path)
+    
+    if n_experts % mp != 0:
+        raise ValueError(f"Number of experts {n_experts} must be divisible by model parallelism factor {mp}")
+    
     n_local_experts = n_experts // mp
     state_dicts = [{} for _ in range(mp)]
-
-    for file_path in tqdm(glob(os.path.join(hf_ckpt_path, "*.safetensors"))):
-        with safe_open(file_path, framework="pt", device="cpu") as f:
-            for name in f.keys():
-                if "model.layers.61" in name:
-                    continue
-                param: torch.Tensor = f.get_tensor(name)
-                if name.startswith("model."):
-                    name = name[len("model."):]
-                name = name.replace("self_attn", "attn")
-                name = name.replace("mlp", "ffn")
-                name = name.replace("weight_scale_inv", "scale")
-                name = name.replace("e_score_correction_bias", "bias")
-                key = name.split(".")[-2]
-                assert key in mapping
-                new_key, dim = mapping[key]
-                name = name.replace(key, new_key)
-                for i in range(mp):
-                    new_param = param
-                    if "experts" in name and "shared_experts" not in name:
-                        idx = int(name.split(".")[-3])
-                        if idx < i * n_local_experts or idx >= (i + 1) * n_local_experts:
-                            continue
-                    elif dim is not None:
-                        assert param.size(dim) % mp == 0
-                        shard_size = param.size(dim) // mp
-                        new_param = param.narrow(dim, i * shard_size, shard_size).contiguous()
-                    state_dicts[i][name] = new_param
-
-    os.makedirs(save_path, exist_ok=True)
-
-    for i in trange(mp):
-        save_file(state_dicts[i], os.path.join(save_path, f"model{i}-mp{mp}.safetensors"))
-
-    for file_path in glob(os.path.join(hf_ckpt_path, "*token*")):
-        new_file_path = os.path.join(save_path, os.path.basename(file_path))
-        shutil.copyfile(file_path, new_file_path)
-
+    
+    process_checkpoint_files(hf_ckpt_path, mp, n_local_experts, state_dicts)
+    save_output_files(state_dicts, save_path, mp, hf_ckpt_path)
+    
+    logger.info(f"Successfully converted checkpoints. Output saved to {save_path}")
 
 if __name__ == "__main__":
-    parser = ArgumentParser()
-    parser.add_argument("--hf-ckpt-path", type=str, required=True)
-    parser.add_argument("--save-path", type=str, required=True)
-    parser.add_argument("--n-experts", type=int, required=True)
-    parser.add_argument("--model-parallel", type=int, required=True)
+    parser = ArgumentParser(description="Convert HuggingFace checkpoints to distributed format")
+    parser.add_argument(
+        "--hf-ckpt-path",
+        type=str,
+        required=True,
+        help="Path to input HuggingFace checkpoint directory"
+    )
+    parser.add_argument(
+        "--save-path",
+        type=str,
+        required=True,
+        help="Output directory for converted checkpoints"
+    )
+    parser.add_argument(
+        "--n-experts",
+        type=int,
+        required=True,
+        help="Total number of experts in the model"
+    )
+    parser.add_argument(
+        "--model-parallel",
+        type=int,
+        required=True,
+        dest="model_parallel",
+        help="Model parallelism factor"
+    )
+    
     args = parser.parse_args()
-    assert args.n_experts % args.model_parallel == 0
-    main(args.hf_ckpt_path, args.save_path, args.n_experts, args.model_parallel)
+    
+    try:
+        main(
+            args.hf_ckpt_path,
+            args.save_path,
+            args.n_experts,
+            args.model_parallel
+        )
+    except Exception as e:
+        logger.error(f"Conversion failed: {str(e)}")
+        raise