= Gerrit Code Review - Change metadata plugin API This API is provided by link:pg-plugin-dev.html#change-metadata[plugin.changeMetadata()] and provides interface for customization and data updates of change metadata. == onLabelsChanged `changeMetadataApi.onLabelsChanged(callback)` .Params - *callback* function that's executed when labels changed on the server. Callback receives labels with scores applied to the change, map of the label names to link:rest-api-changes.html#label-info[LabelInfo] entries .Returns - `GrChangeMetadataApi` for chaining.