Recover storage headroom only after writes and deletions are known

Measure committed bytes, not just visible content

A workspace’s visible messages are only part of its storage accounting. Lupin’s storage overview separates stored, reserved, deleting and available bytes. Reservations represent writes whose outcome is not yet finalized, and unfinished deletions still consume capacity. The difference prevents concurrent workers from each assuming that the same space is free.

Read /v0/billing/storage through an authorized account and preserve the observation timestamp. A user deleting a large item in the console does not establish that the underlying object was removed. The accounting must wait for confirmation before making that capacity available to another writer.

Investigate unknown writes before releasing space

A failed write response can leave the object store and local state out of sync. The object may exist even if the worker did not receive an acknowledgment. Lupin keeps unknown write reservations rather than treating the failure as zero bytes. Reconcile the saved write identity and object evidence through the supported operator path.

Do not simply subtract the expected object size from the total or retry under a fresh identifier. A replacement can allocate another immutable version while the first remains present. The useful repair establishes which version exists and how the original reservation should settle or release.

Wait for confirmed deletion

Content can be marked for deletion before its backing object is actually gone. If object storage is unavailable, the deleting category can remain elevated even though the application no longer shows the body. This is a valid intermediate state, not proof that accounting should ignore it.

Lupin documents that deleting an R2 object frees capacity only after deletion is confirmed. Keep cleanup work durable and retryable without claiming immediate success. For an incident report, record deletion state and object confirmation separately from the user’s original deletion request. Avoid exporting the private object contents as evidence.

Keep retention and usage history distinct

Content expiry and permanent usage accounting solve different problems. Expired bodies can be removed while message metadata and ledger records remain. Provider operation journals also retain reconciliation and idempotency material separately from content expiry, so a retention policy is not a promise to erase every diagnostic or financial record.

Changing the retention window applies to future content by default. Applying it to existing content requires the separate confirmation described in billing documentation and starts a full new window. It is not an immediate emergency purge switch, and extending retention cannot restore content already deleted.

Plan within the real hard cap

Retained storage currently has a hard cap and no storage overage billing flow. Enabling another product’s paid overages does not expand byte capacity. Account for reserved and deleting bytes when deciding whether a new upload fits, and handle a fresh admission rejection if concurrent work changes the available headroom.

Test local storage fixtures with a successful write whose acknowledgment is lost, a failed delete and a confirmed delete. The expected sequence preserves capacity until evidence resolves it. Also verify that a missing exact message body returns its documented unavailable error rather than an empty successful body that could conceal data loss.

Sources & verification

Reviewed against the checked-in Lupin implementation and official reference documentation on 2026-11-05. Operational examples are illustrative; no live paid action, provider mutation or external message was executed.

• Lupin billing, metering and retained storage ↗Checked 2026-11-05
• Lupin usage ledger and spending limits ↗Checked 2026-11-05

Prepared with AI assistance by Lupin editorial. How we research and maintain these guides.