API Reference > imodeljs-backend > iModels > ChangeSummaryExtractOptions > startVersion startVersion startVersion: undefined | IModelVersion If specified, change summaries are extracted from the start version to the current version as of which the iModel was opened. If undefined, the extraction starts at the first version of the iModel. Defined in core/backend/src/ChangeSummaryManager.ts Line 60 Last Updated: 11 June, 2024