aether-cloudlink-mqtt

Broker-neutral MQTT v3.1.1/QoS 1 binding for the experimental CloudLink edge foundation. It validates a user-selected endpoint, TLS/authentication settings, topic prefix and gateway namespace; publishes with retain = false; subscribes only to the same gateway’s session/ACK/replay topics; correlates QoS 1 PUBACK; and reconnects independently of local edge behavior.

PUBACK is transport evidence only. The dedicated CloudLink spool is removed only by a validated application durable ACK.

The adapter carries already-authenticated CloudLink bytes; it never invents a signature. Gateway-signed composition uses the session Gateway key for heartbeats and all durable uplinks. Persisted delivery facts keep their original timestamps and business identity across restart, while a newer session signs them again with its new session binding. The explicit trusted connector test profile depends on broker-side attestation and normally omits payload authentication.

The experimental aether.cloudlink.integration.v1alpha1 extension adds up/integration/topology and up/integration/observations. It remains disabled until a compatible Cloud consumer is enabled first and the Runtime Manifest explicitly declares the extension. Topology and observations use independent durable streams. Topology is atomic; observation batches may split only between complete observations. Each complete MQTT payload is limited to 256 KiB, and both routes reuse application-level durable ACK and replay. Neither route provides physical control.

The separate crate feature integration-control exposes the exact experimental offer and receipt topic namespace plus explicitly activated transport methods. Those routes remain absent from every baseline connection. aether-io activates them only after accepting the current CloudLink session and persisting its new epoch; reconnecting resets them to disabled until the new session repeats that activation. Receipt PUBACK is transport evidence and never removes the durable receipt. Signature verification, topology and local policy, audit, deduplication, and runtime settings remain in the composition and application layers rather than this MQTT adapter.

Default tests need no broker. See docs/reference/cloudlink-mqtt-v1.md for the opt-in shared-broker harness and environment variables.