diff --git a/openai/assistant.go b/openai/assistant.go
index d664a1a..651e9c1 100644
--- a/openai/assistant.go
+++ b/openai/assistant.go
@@ -103,10 +103,10 @@ type AssistantToolResources struct {
 	} `json:"code_interpreter,omitempty"`
 	FileSearch *struct {
 		VectorStoreIDs []string `json:"vector_store_ids"`
-		VectorStore    *struct {
+		VectorStores   *struct {
 			FileIDs  []string          `json:"file_ids"`
 			MetaData map[string]string `json:"metadata,omitempty"`
-		} `json:"vector_store,omitempty"`
+		} `json:"vector_stores,omitempty"`
 	} `json:"file_search,omitempty"`
 }
 
diff --git a/openai/endpoint.go b/openai/endpoint.go
index 31dd76a..e5cf5f3 100644
--- a/openai/endpoint.go
+++ b/openai/endpoint.go
@@ -61,6 +61,6 @@ func (e *endpoint) newRequest(method string, u *url.URL, body interface{}) (*htt
 
 func (e *betaEndpoint) newRequest(method string, u *url.URL, body interface{}) (*http.Request, error) {
 	req, err := e.Client.newRequest(method, u, body)
-	req.Header.Set("OpenAI-Beta", "assistants=v1")
+	req.Header.Set("OpenAI-Beta", "assistants=v2")
 	return req, err
 }