diff --git a/lightrag/base.py b/lightrag/base.py
index ae451dda..1d7a0a98 100644
--- a/lightrag/base.py
+++ b/lightrag/base.py
@@ -1,13 +1,13 @@
+from __future__ import annotations
+
 import os
 from dataclasses import dataclass, field
 from enum import Enum
 from typing import (
     Any,
     Literal,
-    Optional,
     TypedDict,
     TypeVar,
-    Union,
 )
 
 import numpy as np
@@ -115,7 +115,7 @@ class BaseVectorStorage(StorageNameSpace):
 class BaseKVStorage(StorageNameSpace):
     embedding_func: EmbeddingFunc | None = None
 
-    async def get_by_id(self, id: str) -> Union[dict[str, Any], None]:
+    async def get_by_id(self, id: str) -> dict[str, Any] | None:
         raise NotImplementedError
 
     async def get_by_ids(self, ids: list[str]) -> list[dict[str, Any]]:
@@ -157,21 +157,23 @@ class BaseGraphStorage(StorageNameSpace):
 
     """Get a node by its id."""
 
-    async def get_node(self, node_id: str) -> Union[dict[str, str], None]:
+    async def get_node(self, node_id: str) -> dict[str, str] | None:
         raise NotImplementedError
 
     """Get an edge by its source and target node ids."""
 
     async def get_edge(
-        self, source_node_id: str, target_node_id: str
-    ) -> Union[dict[str, str], None]:
+        self, 
+        source_node_id: str, 
+        target_node_id: str
+    ) -> dict[str, str] | None :
         raise NotImplementedError
 
     """Get all edges connected to a node."""
 
     async def get_node_edges(
         self, source_node_id: str
-    ) -> Union[list[tuple[str, str]], None]:
+    ) -> list[tuple[str, str]] | None:
         raise NotImplementedError
 
     """Upsert a node into the graph."""
@@ -236,9 +238,9 @@ class DocProcessingStatus:
     """ISO format timestamp when document was created"""
     updated_at: str
     """ISO format timestamp when document was last updated"""
-    chunks_count: Optional[int] = None
+    chunks_count: int | None = None
     """Number of chunks after splitting, used for processing"""
-    error: Optional[str] = None
+    error: str | None = None
     """Error message if failed"""
     metadata: dict[str, Any] = field(default_factory=dict)
     """Additional metadata"""
diff --git a/lightrag/exceptions.py b/lightrag/exceptions.py
index 5de6b334..ae756f85 100644
--- a/lightrag/exceptions.py
+++ b/lightrag/exceptions.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import httpx
 from typing import Literal
 
diff --git a/lightrag/lightrag.py b/lightrag/lightrag.py
index af241f65..fed555a2 100644
--- a/lightrag/lightrag.py
+++ b/lightrag/lightrag.py
@@ -6,7 +6,7 @@ import configparser
 from dataclasses import asdict, dataclass, field
 from datetime import datetime
 from functools import partial
-from typing import Any, AsyncIterator, Callable, Iterator, Optional, Union, cast
+from typing import Any, AsyncIterator, Callable, Iterator, cast
 
 from .base import (
     BaseGraphStorage,
@@ -314,7 +314,7 @@ class LightRAG:
     """Maximum number of concurrent embedding function calls."""
 
     # LLM Configuration
-    llm_model_func: Union[Callable[..., object], None] = None
+    llm_model_func: Callable[..., object] | None = None
     """Function for interacting with the large language model (LLM). Must be set before use."""
 
     llm_model_name: str = "meta-llama/Llama-3.2-1B-Instruct"
@@ -354,7 +354,7 @@ class LightRAG:
     chunking_func: Callable[
         [
             str,
-            Optional[str],
+            str | None,
             bool,
             int,
             int,
diff --git a/lightrag/llm.py b/lightrag/llm.py
index b4baef68..e5f98cf8 100644
--- a/lightrag/llm.py
+++ b/lightrag/llm.py
@@ -1,4 +1,6 @@
-from typing import List, Dict, Callable, Any
+from __future__ import annotations
+
+from typing import Callable, Any
 from pydantic import BaseModel, Field
 
 
@@ -23,7 +25,7 @@ class Model(BaseModel):
         ...,
         description="A function that generates the response from the llm. The response must be a string",
     )
-    kwargs: Dict[str, Any] = Field(
+    kwargs: dict[str, Any] = Field(
         ...,
         description="The arguments to pass to the callable function. Eg. the api key, model name, etc",
     )
@@ -57,7 +59,7 @@ class MultiModel:
         ```
     """
 
-    def __init__(self, models: List[Model]):
+    def __init__(self, models: list[Model]):
         self._models = models
         self._current_model = 0
 
diff --git a/lightrag/namespace.py b/lightrag/namespace.py
index ba8e3072..77e04c9e 100644
--- a/lightrag/namespace.py
+++ b/lightrag/namespace.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import Iterable
 
 
diff --git a/lightrag/operate.py b/lightrag/operate.py
index f2bd6218..37e7523f 100644
--- a/lightrag/operate.py
+++ b/lightrag/operate.py
@@ -1,8 +1,10 @@
+from __future__ import annotations
+
 import asyncio
 import json
 import re
 from tqdm.asyncio import tqdm as tqdm_async
-from typing import Any, AsyncIterator, Union
+from typing import Any, AsyncIterator
 from collections import Counter, defaultdict
 from .utils import (
     logger,
@@ -36,7 +38,7 @@ import time
 
 def chunking_by_token_size(
     content: str,
-    split_by_character: Union[str, None] = None,
+    split_by_character: str | None = None,
     split_by_character_only: bool = False,
     overlap_token_size: int = 128,
     max_token_size: int = 1024,
@@ -297,7 +299,7 @@ async def extract_entities(
     relationships_vdb: BaseVectorStorage,
     global_config: dict[str, str],
     llm_response_cache: BaseKVStorage | None = None,
-) -> Union[BaseGraphStorage, None]:
+) -> BaseGraphStorage | None:
     use_llm_func: callable = global_config["llm_model_func"]
     entity_extract_max_gleaning = global_config["entity_extract_max_gleaning"]
     enable_llm_cache_for_entity_extract: bool = global_config[
diff --git a/lightrag/prompt.py b/lightrag/prompt.py
index 160663d9..f4f5e38a 100644
--- a/lightrag/prompt.py
+++ b/lightrag/prompt.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 GRAPH_FIELD_SEP = "<SEP>"
 
 PROMPTS = {}
diff --git a/lightrag/types.py b/lightrag/types.py
index 9c8e0099..2510bed3 100644
--- a/lightrag/types.py
+++ b/lightrag/types.py
@@ -1,16 +1,19 @@
+
+from __future__ import annotations
+
 from pydantic import BaseModel
-from typing import List, Dict, Any
+from typing import Any
 
 
 class GPTKeywordExtractionFormat(BaseModel):
-    high_level_keywords: List[str]
-    low_level_keywords: List[str]
+    high_level_keywords: list[str]
+    low_level_keywords: list[str]
 
 
 class KnowledgeGraphNode(BaseModel):
     id: str
-    labels: List[str]
-    properties: Dict[str, Any]  # anything else goes here
+    labels: list[str]
+    properties: dict[str, Any]  # anything else goes here
 
 
 class KnowledgeGraphEdge(BaseModel):
@@ -18,9 +21,9 @@ class KnowledgeGraphEdge(BaseModel):
     type: str
     source: str  # id of source node
     target: str  # id of target node
-    properties: Dict[str, Any]  # anything else goes here
+    properties: dict[str, Any]  # anything else goes here
 
 
 class KnowledgeGraph(BaseModel):
-    nodes: List[KnowledgeGraphNode] = []
-    edges: List[KnowledgeGraphEdge] = []
+    nodes: list[KnowledgeGraphNode] = []
+    edges: list[KnowledgeGraphEdge] = []
diff --git a/lightrag/utils.py b/lightrag/utils.py
index 9b18d0c2..5b86ee78 100644
--- a/lightrag/utils.py
+++ b/lightrag/utils.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import asyncio
 import html
 import io
@@ -9,7 +11,7 @@ import re
 from dataclasses import dataclass
 from functools import wraps
 from hashlib import md5
-from typing import Any, Callable, Union, List, Optional
+from typing import Any, Callable
 import xml.etree.ElementTree as ET
 import bs4
 
@@ -72,7 +74,7 @@ class ReasoningResponse:
     tag: str
 
 
-def locate_json_string_body_from_string(content: str) -> Union[str, None]:
+def locate_json_string_body_from_string(content: str) -> str | None:
     """Locate the JSON string body from a string"""
     try:
         maybe_json_str = re.search(r"{.*}", content, re.DOTALL)
@@ -238,7 +240,7 @@ def truncate_list_by_token_size(
     return list_data
 
 
-def list_of_list_to_csv(data: List[List[str]]) -> str:
+def list_of_list_to_csv(data: list[list[str]]) -> str:
     output = io.StringIO()
     writer = csv.writer(
         output,
@@ -251,7 +253,7 @@ def list_of_list_to_csv(data: List[List[str]]) -> str:
     return output.getvalue()
 
 
-def csv_string_to_list(csv_string: str) -> List[List[str]]:
+def csv_string_to_list(csv_string: str) -> list[list[str]]:
     # Clean the string by removing NUL characters
     cleaned_string = csv_string.replace("\0", "")
 
@@ -382,7 +384,7 @@ async def get_best_cached_response(
     llm_func=None,
     original_prompt=None,
     cache_type=None,
-) -> Union[str, None]:
+) -> str | None:
     logger.debug(
         f"get_best_cached_response:  mode={mode} cache_type={cache_type} use_llm_check={use_llm_check}"
     )
@@ -486,7 +488,7 @@ def cosine_similarity(v1, v2):
     return dot_product / (norm1 * norm2)
 
 
-def quantize_embedding(embedding: Union[np.ndarray, list], bits=8) -> tuple:
+def quantize_embedding(embedding: np.ndarray | list[float], bits: int=8) -> tuple:
     """Quantize embedding to specified bits"""
     # Convert list to numpy array if needed
     if isinstance(embedding, list):
@@ -577,9 +579,9 @@ class CacheData:
     args_hash: str
     content: str
     prompt: str
-    quantized: Optional[np.ndarray] = None
-    min_val: Optional[float] = None
-    max_val: Optional[float] = None
+    quantized: np.ndarray | None = None
+    min_val: float | None = None
+    max_val: float | None = None
     mode: str = "default"
     cache_type: str = "query"