diff --git a/relay/adaptor/vertexai/adaptor.go b/relay/adaptor/vertexai/adaptor.go
index cf5d4c48..3fab4a45 100644
--- a/relay/adaptor/vertexai/adaptor.go
+++ b/relay/adaptor/vertexai/adaptor.go
@@ -63,20 +63,36 @@ func (a *Adaptor) GetRequestURL(meta *meta.Meta) (string, error) {
 	suffix := ""
 	if strings.HasPrefix(meta.ActualModelName, "gemini") {
 		if meta.IsStream {
-			suffix = "streamGenerateContent"
+			suffix = "streamGenerateContent?alt=sse"
 		} else {
 			suffix = "generateContent"
 		}
 	} else {
 		if meta.IsStream {
-			suffix = "streamRawPredict"
+			suffix = "streamRawPredict?alt=sse"
 		} else {
 			suffix = "rawPredict"
 		}
 	}
 
-	baseUrl := fmt.Sprintf("https://%s-aiplatform.googleapis.com/v1/projects/%s/locations/%s/publishers/google/models/%s:%s", meta.Config.Region, meta.Config.VertexAIProjectID, meta.Config.Region, meta.ActualModelName, suffix)
-	return baseUrl, nil
+	if meta.BaseURL != "" {
+		return fmt.Sprintf(
+			"%s/v1/projects/%s/locations/%s/publishers/google/models/%s:%s",
+			meta.BaseURL,
+			meta.Config.VertexAIProjectID,
+			meta.Config.Region,
+			meta.ActualModelName,
+			suffix,
+		), nil
+	}
+	return fmt.Sprintf(
+		"https://%s-aiplatform.googleapis.com/v1/projects/%s/locations/%s/publishers/google/models/%s:%s",
+		meta.Config.Region,
+		meta.Config.VertexAIProjectID,
+		meta.Config.Region,
+		meta.ActualModelName,
+		suffix,
+	), nil
 }
 
 func (a *Adaptor) SetupRequestHeader(c *gin.Context, req *http.Request, meta *meta.Meta) error {
diff --git a/relay/adaptor/vertexai/claude/adapter.go b/relay/adaptor/vertexai/claude/adapter.go
index aab39864..b39e2dda 100644
--- a/relay/adaptor/vertexai/claude/adapter.go
+++ b/relay/adaptor/vertexai/claude/adapter.go
@@ -31,6 +31,7 @@ func (a *Adaptor) ConvertRequest(c *gin.Context, relayMode int, request *model.G
 		AnthropicVersion: anthropicVersion,
 		// Model:            claudeReq.Model,
 		Messages:    claudeReq.Messages,
+		System:      claudeReq.System,
 		MaxTokens:   claudeReq.MaxTokens,
 		Temperature: claudeReq.Temperature,
 		TopP:        claudeReq.TopP,