> ## Documentation Index
> Fetch the complete documentation index at: https://headgate.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Workers and leases

> Capacity reporting, lease renewal, fencing, graceful shutdown, and crash recovery.

Workers are consumers of admission decisions. They register typed handlers, report free
capacity, renew active leases, and return outcomes through fence-verified acknowledgements.

## Lease fencing

Every claim receives a lease identity and monotonically meaningful fence. Renew, progress,
output, checkpoints, and acknowledgements include that identity. Once the lease is lost,
the old holder cannot overwrite the new holder's work.

<Warning>
  A lost lease is a stop signal, never a warning to log and ignore. The runtime cancels the
  handler and rejects later writes from that attempt.
</Warning>

## Failure and shutdown behavior

* Panic recovery is enabled by default.
* Each attempt is isolated from sibling attempts.
* An expired lease increments `crash_attempt`, not `attempt`.
* Graceful shutdown stops admission before draining.
* Workers keep renewing leases while they drain.
* Work left after the bounded shutdown is voluntarily released without charging failure.
* Singleton scheduler and maintenance duties use store leases, not a second election system.

See [worker configuration](/docs/reference/configuration) for capacity, lease, heartbeat,
poll backoff, shutdown, and memory guard settings.