Oban Essentials

Use this skill before writing ANY Oban worker or enqueuing jobs.

Canonical FP bar: docs/fcis-engineering-rules.md — Functional Core, Imperative Shell: pure domain modules; side effects at edges. Workers and pipelines are edges: fetch IDs, call pure core, return tagged tuples.

End-to-End Workflow

When setting up a new Oban worker, follow these steps in order:

1. Add queue to config — define the queue name and concurrency in config/config.exs
2. Define worker module — use Oban.Worker with explicit queue, max_attempts, and unique options
3. Enqueue from context — call Oban.insert/1 inside a context function, not a LiveView
4. Write tests — use Oban.Testing with assert_enqueued and perform_job, covering all return paths

RULES — Follow these with no exceptions