iCloud Drive

iCloud Drive has no public API, but on macOS and Windows the official client mirrors it to a local folder — and a local folder is blitcp's home turf. Copy into it with dedup and verification; Apple's client handles the sync to the cloud.

Where the folder lives

OS	Path
macOS	`~/Library/Mobile Documents/com~apple~CloudDocs/`
Windows	`%USERPROFILE%\iCloudDrive\` (iCloud for Windows installed)

Back up to it

# macOS
blitcp ~/Documents/projects "~/Library/Mobile Documents/com~apple~CloudDocs/backups/projects"

# Windows
blitcp C:\projects %USERPROFILE%\iCloudDrive\backups\projects

Everything blitcp does locally applies: duplicate content is hard-linked instead of stored twice (APFS also supports clones), the copy is verified, and re-runs only touch changed files — which also keeps the amount Apple's client has to re-sync to a minimum.

Honest limits

blitcp verifies the copy into the folder; the folder-to-cloud leg belongs to Apple's client, including its “Optimize Storage” eviction (evicted placeholders re-download on read). A native icloud:// backend is on the roadmap as an experimental backend; until then this local-folder route is the supported path.