diff --git a/checkpoint.py b/checkpoint.py
index 1c6e878..a5452c2 100644
--- a/checkpoint.py
+++ b/checkpoint.py
@@ -39,8 +39,19 @@ rank_logger = logging.getLogger("rank")
 sys.modules['__main__'].QuantizedWeight8bit = QuantizedWeight8bit
 
 
+# Utility functions for file handling and shared memory
+
 @contextlib.contextmanager
 def copy_to_shm(file: str):
+    """
+    Context manager to copy a file to shared memory.
+
+    Args:
+        file (str): The path to the file to be copied.
+
+    Yields:
+        str: The path to the copied file in shared memory.
+    """
     if file.startswith("/dev/shm/"):
         # Nothing to do, the file is already in shared memory.
         yield file
@@ -58,6 +69,15 @@ def copy_to_shm(file: str):
 
 @contextlib.contextmanager
 def copy_from_shm(file: str):
+    """
+    Context manager to copy a file from shared memory.
+
+    Args:
+        file (str): The path to the file to be copied.
+
+    Yields:
+        str: The path to the temporary file in shared memory.
+    """
     tmp_dir = "/dev/shm/"
     fd, tmp_path = tempfile.mkstemp(dir=tmp_dir)
     try:
@@ -69,19 +89,48 @@ def copy_from_shm(file: str):
 
 
 def fast_unpickle(path: str) -> Any:
+    """
+    Unpickle an object from a file using shared memory for faster loading.
+
+    Args:
+        path (str): The path to the file containing the pickled object.
+
+    Returns:
+        Any: The unpickled object.
+    """
     with copy_to_shm(path) as tmp_path:
         with open(tmp_path, "rb") as f:
             return pickle.load(f)
 
 
 def fast_pickle(obj: Any, path: str) -> None:
+    """
+    Pickle an object to a file using shared memory for faster saving.
+
+    Args:
+        obj (Any): The object to be pickled.
+        path (str): The path to the file where the object will be saved.
+    """
     with copy_from_shm(path) as tmp_path:
         with open(tmp_path, "wb") as f:
             pickle.dump(obj, f)
 
 
+# Tensor loading and path handling
+
 def load_tensors(shaped_arrays, directory, mesh_config, tensor_indices=None):
-    """Loads a set of arrays."""
+    """
+    Load a set of arrays from files in parallel using a thread pool.
+
+    Args:
+        shaped_arrays (list): A list of shaped arrays to be loaded.
+        directory (str): The directory containing the tensor files.
+        mesh_config (tuple): The mesh configuration.
+        tensor_indices (list, optional): The indices of the tensors to load. Defaults to None.
+
+    Returns:
+        list: A list of loaded arrays.
+    """
     pool = ThreadPoolExecutor(max_workers=32)
     fs = list()
     num_tensors = 0
@@ -108,6 +157,15 @@ def load_tensors(shaped_arrays, directory, mesh_config, tensor_indices=None):
 
 
 def path_tuple_to_string(path: tuple) -> str:
+    """
+    Convert a path tuple to a string representation.
+
+    Args:
+        path (tuple): The path tuple.
+
+    Returns:
+        str: The string representation of the path.
+    """
     pieces = []
     for elem in path:
         if isinstance(elem, jax.tree_util.DictKey):
@@ -124,6 +182,17 @@ def get_load_path_str(
     load_rename_rules: Optional[list[tuple[str, str]]] = None,
     load_exclude_rules: Optional[list[str]] = None,
 ) -> Optional[str]:
+    """
+    Get the load path string based on the initial path string and renaming/exclusion rules.
+
+    Args:
+        init_path_str (str): The initial path string.
+        load_rename_rules (list[tuple[str, str]], optional): The renaming rules. Defaults to None.
+        load_exclude_rules (list[str], optional): The exclusion rules. Defaults to None.
+
+    Returns:
+        Optional[str]: The load path string if not excluded, otherwise None.
+    """
     # Exclusion
     if load_exclude_rules is not None:
         for search_pattern in load_exclude_rules:
@@ -148,6 +217,19 @@ def replace_with_load_state(
     load_exclude_rules: Optional[list[str]] = None,
     mesh_config: tuple = (1, 1),
 ) -> Any:
+    """
+    Replace the initial state with the loaded state based on renaming and exclusion rules.
+
+    Args:
+        init_state (Any): The initial state.
+        load_state (Any): The loaded state.
+        load_rename_rules (list[tuple[str, str]], optional): The renaming rules. Defaults to None.
+        load_exclude_rules (list[str], optional): The exclusion rules. Defaults to None.
+        mesh_config (tuple, optional): The mesh configuration. Defaults to (1, 1).
+
+    Returns:
+        Any: The replaced state.
+    """
     flatten_load, _ = jax.tree_util.tree_flatten_with_path(load_state)
     flatten_init, structure_init = jax.tree_util.tree_flatten_with_path(init_state)
     load_map = {path_tuple_to_string(path): tensor for path, tensor in flatten_load}
@@ -177,6 +259,8 @@ def replace_with_load_state(
     return jax.tree_util.tree_unflatten(structure_init, replaced)
 
 
+# Checkpoint restoration
+
 def restore(
     checkpoint_path: str,
     state_shapes: Any,
@@ -186,6 +270,21 @@ def restore(
     state_sharding,
     init_state: Optional[Any] = None,
 ) -> Any:
+    """
+    Restore the state from a checkpoint.
+
+    Args:
+        checkpoint_path (str): The path to the checkpoint directory.
+        state_shapes (Any): The shapes of the state.
+        mesh: The mesh configuration.
+        between_hosts_config: The configuration for communication between hosts.
+        params_only (bool): Whether to restore only the parameters.
+        state_sharding: The sharding specification for the state.
+        init_state (Optional[Any], optional): The initial state. Defaults to None.
+
+    Returns:
+        Any: The restored state.
+    """
     ckpt_path = os.path.join(checkpoint_path, "ckpt-0")
 
     rank_logger.info("Loading checkpoint at {}".format(ckpt_path))