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.

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.