Phoenix Contexts Reference

Ash projects: Ash.Domain replaces Phoenix contexts for data access — use the ash-framework skill. Context boundary and PubSub patterns still apply.

Reference for designing and implementing Phoenix contexts (bounded contexts).

Iron Laws — Never Violate These

1. CONTEXTS OWN THEIR DATA — Never query another context's schema directly via Repo
2. SCOPES ARE MANDATORY (Phoenix 1.8+) — Every context function MUST accept scope as first parameter
3. THIN CONTROLLERS/LIVEVIEWS — Controllers translate HTTP, business logic stays in contexts
4. NO SIDE EFFECTS IN SCHEMAS — Use Ecto.Multi for transactions with side effects

Context Structure