Effect Foundations & Style

Purpose: Provide a compact, go-to checklist for writing idiomatic Effect TypeScript with data-first pipe style, minimal imperative code, and strong typing. Optimized for a coding agent with limited context.

Triggers

• New Effect implementation or refactor
• Selecting map/flatMap/andThen/tap operators
• Converting promise/callback to Effect

When to use

• You’re unsure which operator to pick (map vs flatMap vs andThen vs tap)
• You need a minimal template for sequential vs parallel code
• You want to keep error and context channels explicit (Effect<E, A, R>)