diff --git a/metagpt/rag/factories/index.py b/metagpt/rag/factories/index.py
index 6da4900a0..4e6d6b167 100644
--- a/metagpt/rag/factories/index.py
+++ b/metagpt/rag/factories/index.py
@@ -30,7 +30,7 @@ class RAGIndexFactory(ConfigBasedFactory):
             BM25IndexConfig: self._create_bm25,
             ElasticsearchIndexConfig: self._create_es,
             ElasticsearchKeywordIndexConfig: self._create_es,
-            MilvusIndexConfig: self._create_milvus
+            MilvusIndexConfig: self._create_milvus,
         }
         super().__init__(creators)
 
diff --git a/metagpt/rag/factories/retriever.py b/metagpt/rag/factories/retriever.py
index 3342b8905..490df4906 100644
--- a/metagpt/rag/factories/retriever.py
+++ b/metagpt/rag/factories/retriever.py
@@ -139,7 +139,9 @@ class RetrieverFactory(ConfigBasedFactory):
 
     @get_or_build_index
     def _build_milvus_index(self, config: MilvusRetrieverConfig, **kwargs) -> VectorStoreIndex:
-        vector_store = MilvusVectorStore(uri=config.uri, collection_name=config.collection_name, token=config.token, dim=config.dimensions)
+        vector_store = MilvusVectorStore(
+            uri=config.uri, collection_name=config.collection_name, token=config.token, dim=config.dimensions
+        )
 
         return self._build_index_from_vector_store(config, vector_store, **kwargs)
 
diff --git a/metagpt/rag/retrievers/milvus_retriever.py b/metagpt/rag/retrievers/milvus_retriever.py
index ff2562bd8..bcc66330b 100644
--- a/metagpt/rag/retrievers/milvus_retriever.py
+++ b/metagpt/rag/retrievers/milvus_retriever.py
@@ -14,4 +14,4 @@ class MilvusRetriever(VectorIndexRetriever):
     def persist(self, persist_dir: str, **kwargs) -> None:
         """Support persist.
 
-        Milvus automatically saves, so there is no need to implement."""
\ No newline at end of file
+        Milvus automatically saves, so there is no need to implement."""
diff --git a/metagpt/rag/schema.py b/metagpt/rag/schema.py
index e4d97068d..1e04a546f 100644
--- a/metagpt/rag/schema.py
+++ b/metagpt/rag/schema.py
@@ -8,7 +8,7 @@ from llama_index.core.embeddings import BaseEmbedding
 from llama_index.core.indices.base import BaseIndex
 from llama_index.core.schema import TextNode
 from llama_index.core.vector_stores.types import VectorStoreQueryMode
-from pydantic import BaseModel, ConfigDict, Field, PrivateAttr, model_validator, validator
+from pydantic import BaseModel, ConfigDict, Field, PrivateAttr, model_validator
 
 from metagpt.config2 import config
 from metagpt.configs.embedding_config import EmbeddingType
@@ -199,6 +199,7 @@ class ChromaIndexConfig(VectorIndexConfig):
         default=None, description="Optional metadata to associate with the collection"
     )
 
+
 class MilvusIndexConfig(VectorIndexConfig):
     """Config for milvus-based index."""
 
diff --git a/metagpt/utils/token_counter.py b/metagpt/utils/token_counter.py
index 9d219d197..c922f2cb4 100644
--- a/metagpt/utils/token_counter.py
+++ b/metagpt/utils/token_counter.py
@@ -241,7 +241,6 @@ TOKEN_MAX = {
     "gpt-4-0613": 8192,
     "gpt-4-32k": 32768,
     "gpt-4-32k-0613": 32768,
-    "gpt-4o-mini": 128000,
     "gpt-3.5-turbo-0125": 16385,
     "gpt-3.5-turbo": 16385,
     "gpt-3.5-turbo-1106": 16385,
@@ -496,4 +495,4 @@ async def get_openrouter_tokens(chunk: ChatCompletionChunk) -> CompletionUsage:
     usage = CompletionUsage(
         prompt_tokens=tokens_prompt, completion_tokens=completion_tokens, total_tokens=tokens_prompt + completion_tokens
     )
-    return usage
\ No newline at end of file
+    return usage
diff --git a/tests/metagpt/rag/factories/test_index.py b/tests/metagpt/rag/factories/test_index.py
index 9861e1242..e084eb6e7 100644
--- a/tests/metagpt/rag/factories/test_index.py
+++ b/tests/metagpt/rag/factories/test_index.py
@@ -7,7 +7,8 @@ from metagpt.rag.schema import (
     ChromaIndexConfig,
     ElasticsearchIndexConfig,
     ElasticsearchStoreConfig,
-    FAISSIndexConfig, MilvusIndexConfig,
+    FAISSIndexConfig,
+    MilvusIndexConfig,
 )