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I've consulted other engineers about this. First, currently, there is no UWP capability available at this time. Based on the document here: Build a Cloud Sync Engine that Supports Placeholder Files, it mentions that The cloud files API does not currently support implementing cloud sync engines in UWP apps. Cloud sync engines must be implemented in desktop apps.. There is a Cloud Mirror sample on Github shows how to get started writing a cloud files provider using the cloud files API and it is in Preview which is not supported. You could submit a feedback on the Github about your interest.
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