Tasks and attempts

Delivery covers getting a message to a machine. Tasks and attempts cover what happened on it.

Task rows

The hub keeps a task row per unit of agent work, with states that mirror the execution lifecycle: submitted, working, completed, failed, cancelled. The rows are the hub-side record; the node’s A2A execution is the other half of the mirror. A task row survives a hub restart intact — it’s part of the same committed store.

Attempts

An attempt is the recorded outcome of running a delivery on a node. Three endings matter:

• definite — the turn finished (completed, failed, or cancelled) and the node reported it over the /delivery-report leg. The delivery’s delivered state is separate and earlier: it records the ack, the durable handoff receipt the node sent when it mirrored the delivery.
• unknown — the node lost the outcome: the harness died without a verdict, the link dropped mid-report, the machine crashed. The ATTEMPT is recorded as unknown and blocks new work for that recipient until the operator reconciles it. The delivery itself stays delivered (the receipt was real); what is unknown is the turn’s outcome.
• stalled — the turn is running with no progress. The operator can request cancellation; the node carries it through the harness adapter.

Unknown attempts are the deliberate alternative to guessing. The hub surfaces them; the operator reconciles each one — re-run, retire, or investigate — and the reconciliation itself is a committed event.

Why this is two stores

The hub owns the record of what should run and what was reported. The node owns the execution itself. The contract between them is exactly: claim before mirror, ack the handoff receipt, report the outcome after the run — and when the report can’t be produced, say so (an unknown attempt, blocking new work for that recipient).