# Failure Model

<!-- guide: Boundary-level failure semantics. Implementation of mechanisms (queues,
     locks, libraries) belongs to design.md. Remove guides before G3. -->

## Failure Scenarios

| ID | Boundary / step | Failure | Detection | Required system behavior | Observable result | Requirement |
| --- | --- | --- | --- | --- | --- | --- |

## Timeouts and Retries

## Idempotency and Duplicate Handling

<!-- guide: Idempotency key, scope, retention; what a duplicate request/event
     yields. -->

## Ordering and Concurrency

## Partial Failure and Compensation

## Recovery Behavior

## Compatibility During Failure

## Open Questions