diff --git a/dify_client/models/base.py b/dify_client/models/base.py
index f224dcb..ef7741a 100644
--- a/dify_client/models/base.py
+++ b/dify_client/models/base.py
@@ -40,10 +40,10 @@ class CompletionInputs(BaseModel):
 class File(BaseModel):
     type: FileType
     transfer_method: TransferMethod
-    url: Optional[str]
+    url: Optional[str] = None
     # Uploaded file ID, which must be obtained by uploading through the File Upload API in advance
     # (when the transfer method is local_file)
-    upload_file_id: Optional[str]
+    upload_file_id: Optional[str] = None
 
 
 class Usage(BaseModel):
diff --git a/dify_client/models/stream.py b/dify_client/models/stream.py
index 8c6dfe1..da0594d 100644
--- a/dify_client/models/stream.py
+++ b/dify_client/models/stream.py
@@ -27,18 +27,22 @@ class StreamEvent(StrEnum):
     ERROR = "error"
     PING = "ping"
     TTS_MESSAGE_END = "tts_message_end"
-    
+    PARALLEL_BRANCH_STARTED = "parallel_branch_started"
+    PARALLEL_BRANCH_FINISHED = "parallel_branch_finished"
+    NODE_RETRY = "node_retry"
+    AGENT_LOG = "agent_log"
+
     @classmethod
     def new(cls, event: Union["StreamEvent", str]) -> "StreamEvent":
         if isinstance(event, cls):
             return event
-        return utils.str_to_enum(cls, event)
+        return utils.str_to_enum(cls, event, ignore_not_found=True, enum_default=event)
 
 
 class StreamResponse(BaseModel):
     model_config = ConfigDict(extra='allow')
 
-    event: StreamEvent
+    event: StreamEvent | str
     task_id: Optional[str] = ""
 
     @field_validator("event", mode="before")
@@ -65,7 +69,7 @@ class MessageEndStreamResponse(StreamResponse):
     message_id: str
     conversation_id: Optional[str] = ""
     created_at: int  # unix timestamp seconds
-    metadata: Optional[Metadata]
+    metadata: Optional[Metadata] = None
 
 
 class MessageReplaceStreamResponse(MessageStreamResponse):
@@ -104,7 +108,7 @@ class WorkflowsStreamResponse(StreamResponse):
         WorkflowFinishedData,
         NodeStartedData,
         NodeFinishedData]
-    ]
+    ] = None
 
 
 class ChatWorkflowsStreamResponse(WorkflowsStreamResponse):
diff --git a/dify_client/models/workflow.py b/dify_client/models/workflow.py
index 93a1e01..7fad18f 100644
--- a/dify_client/models/workflow.py
+++ b/dify_client/models/workflow.py
@@ -17,15 +17,15 @@ class WorkflowStatus(StrEnum):
 
 
 class ExecutionMetadata(BaseModel):
-    total_tokens: Optional[int]
-    total_price: Optional[str]
-    currency: Optional[str]
+    total_tokens: Optional[int] = None
+    total_price: Optional[str] = None
+    currency: Optional[str] = None
 
 
 class WorkflowStartedData(BaseModel):
     id: str  # workflow run id
     workflow_id: str  # workflow id
-    sequence_number: int
+    sequence_number: int | None = None
     inputs: Optional[dict] = None
     created_at: int  # unix timestamp seconds
 
@@ -66,10 +66,10 @@ class WorkflowFinishedData(BaseModel):
     workflow_id: str  # workflow id
     sequence_number: int
     status: WorkflowStatus
-    outputs: Optional[dict]
-    error: Optional[str]
-    elapsed_time: Optional[float]
-    total_tokens: Optional[int]
+    outputs: Optional[dict] = None
+    error: Optional[str] = None
+    elapsed_time: Optional[float] = None
+    total_tokens: Optional[int] = None
     total_steps: Optional[int] = 0
     created_at: int
     finished_at: int