Module declarations 

Whether a task queue is declared by any deployed .v4 contract. Whether a task queue is declared by any deployed contract.

This reads the SAME durable .v4 worker-contract records the registration handshake admits workers against (crate::worker::contracts) and workflow start admission refuses against (aion::lifecycle NoQueueDeclaration) — there is no second queue-declaration truth in the server.

Fail-open by construction. A server whose catalog declares no queues at all (an engine-less state built from parts, a fresh boot, an embedded engine serving activities in process) can contradict nothing, so it answers QueueDeclaration::Unknown and no structural refusal is ever manufactured from an absence of information. The same holds for a catalog read that could not decode every retained entry — the mixed state the handshake migration creates, old packages retained beside new .v4 ones: what such a read did not find, it may simply not have been able to see. That is the same discipline the handshake lane adopted after its engine-less registration defect — whose observed symptom was this very seam waiting forever at INFO.

Structs

EngineQueueDeclarations

Reads declarations out of the engine’s live workflow catalog.

QueueDeclarationSource

Shared, install-once handle the bridge holds from construction and the boot path fills in once the engine exists.

Enums

QueueDeclaration

What the deployed contract records say about a task queue.

Traits

QueueDeclarations

A reader over the deployed queue declarations.