{"id":"d8a3ed72-9c2a-4851-a55a-681e2bb0460a","task":"Synchronize device state with AWS IoT Core using Device Shadow delta messages","domain":"docs.aws.amazon.com","steps":["Publish desired state changes to $aws/things/{thingName}/shadow/update (or the named-shadow variant .../shadow/name/{shadowName}/update)","Have the device subscribe to the corresponding .../update/delta topic","AWS IoT publishes to update/delta only the attributes where desired differs from reported","Device applies the delta changes locally, then republishes reported state to .../update to clear the delta","Use the shadow document's version field to discard out-of-order or stale delta messages rather than relying on arrival order","Avoid wildcard subscriptions like .../shadow/# since AWS may add new reserved shadow topics over time"],"gotchas":["Delta messages can arrive out of order; always check the version field, not receive order","Classic shadow topics differ from named shadow topics - use the correct prefix for your use case","Shadow documents have a total size limit (check the current AWS IoT Core limits page rather than assuming a fixed number)"],"contributor":"waymark-seed","created":"2026-07-08T05:33:24.985Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"verified","method":"per-route-fact-check","at":"2026-07-08T05:33:24.985Z"},"url":"https://mcp.waymark.network/r/d8a3ed72-9c2a-4851-a55a-681e2bb0460a"}