Attribute Macro processor 

#[processor]

Orchestrator on an #[injectable] provider’s impl block. Each method tagged with #[process(queue = "...", concurrency, retries)] becomes a queue consumer the QueueWorker spawns at boot.

A single provider may carry several #[process] methods (different queues, different concurrencies) sharing the same #[inject] dependencies — pooling related queue handlers on one service keeps shared state (clients, repositories) in one place.

The queue is named either by a raw string literal (legacy form) or by a QueueName type — the preferred form, declared with queue at the feature port: #[process(queue = AudioQueue)]. The type form reads <AudioQueue as QueueName>::NAME into the inventory entry and asserts, at compile time, that this method’s job argument is <AudioQueue as QueueName>::Job — a mismatch is a build error naming both types, not a job that silently never drains.

Per-method attributes (exactly one #[process] per method):

• #[process(queue = "audio")] — minimal, defaults concurrency = 1, retries = 0.
• #[process(queue = "audio", concurrency = 5)] — bound the in-flight jobs per worker.
• #[process(queue = "audio", concurrency = 5, retries = 3)] — apalis retries before the job lands on the queue’s failed list.

The method signature is async fn(&self, job: T) -> anyhow::Result<()>, where T: Job. The macro extracts the job type from the second parameter, generates a typed handler, and submits a per-method inventory entry the worker drains.

Expands to

The impl unchanged, plus per #[process] method: a hidden type-erased handler fn (unwraps the wire envelope, deserializes the job, resolves the provider, dispatches inside the JobContext) and a ProcessMethod submitted to the link-time inventory. No Discoverable — the host’s own #[injectable] owns it.

impl AudioProcessor { /* unchanged */ }
fn __nestrs_process_handler_audio_processor_transcode(payload, container) -> Pin<Box<dyn Future<…>>> { /* … */ }
::nest_rs_core::inventory::submit! {
    ::nest_rs_queue::ProcessMethod {
        name: "AudioProcessor::transcode", queue: "audio",
        concurrency: 5, retries: 3,
        provider_type_id: || TypeId::of::<AudioProcessor>(),
        handler: __nestrs_process_handler_audio_processor_transcode,
    }
}