---
id: INT-15
family: RT-INT
level: core
profiles: [runtime]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/rt-int/int-15
specification: FlowDrop Workflow Specification 1.0-draft
licence: CC BY 4.0
---

# INT-15 — An engine that cannot use a snapshot refuses it, never restarts

*RT-INT (Part II) · level: core · profiles: runtime · added in 1.0*

Silently discarding a snapshot and starting over looks like resilience and is the opposite: it re-runs every side effect the snapshot recorded as already done.

## The rule

> **Normative.** This is the rule.
>
> 1. An engine that cannot consume a snapshot it has been given must refuse, naming the snapshot, and must not silently discard it and start the run from the beginning.
>
> 2. An engine with no snapshot-seeding mechanism therefore refuses any snapshot attached to a run, before any run or job exists.
>
> 3. No snapshot attached remains a plain fresh start.

## Why

Recorded under OPEN-10.

## Related rules

- Names: INT-10, INT-14
- Referenced by: INT-10, INT-14

---

Rule identifiers are permanent and are never renumbered. This specification carries
no implementation status: each implementation publishes its own standing against
these rules. Licensed CC BY 4.0.