diff --git a/relay/claude_handler.go b/relay/claude_handler.go
index d72218de..52736320 100644
--- a/relay/claude_handler.go
+++ b/relay/claude_handler.go
@@ -155,6 +155,7 @@ func ClaudeHelper(c *gin.Context, info *relaycommon.RelayInfo) (newAPIError *typ
 		if err != nil {
 			return types.NewErrorWithStatusCode(err, types.ErrorCodeReadRequestBodyFailed, http.StatusBadRequest, types.ErrOptionWithSkipRetry())
 		}
+		info.UpstreamRequestBodySize = storage.Size()
 		requestBody = common.ReaderOnly(storage)
 	} else {
 		convertedRequest, err := adaptor.ConvertClaudeRequest(c, info, request)