luma-intro-effect-schema

Inventory Zod usage by pattern (objects, transforms, refinements, unions), then convert each using the mapping cheat sheet: z.object becomes Schema.Struct, z.infer becomes typeof X.Type, and .parse becomes Schema.decodeUnknownSync. Migrate shared schemas first, then uninstall zod once no imports remain.

Effect Schema is bidirectional: one schema defines both decode and encode, while Zod's .transform() is one-way. Effect Schema also has three type parameters (Type, Encoded, Requirements), separating wire format from app types and exposing validation dependencies at the type level.

zodResolver cannot be used directly, so an Effect Schema resolver adapter is needed. Check @hookform/resolvers for an official version, or write a thin adapter converting Schema.decodeUnknownEither results into react-hook-form's resolver format.

Use Schema.filterEffect instead of Zod's async .refine(). The dependency (e.g., a database service) appears in the schema's Requirements type parameter, so callers must provide it and tests can inject a test implementation.

Install both effect and @effect/schema, since @effect/schema depends on the effect package. Use whichever package manager the project already uses, detected via its lockfile.

Keeping Zod may be reasonable when form-library adapters become too complex or ORM/tRPC integrations lack Effect Schema support. In that case, confine the Effect Schema to Zod conversion layer to one location to avoid dual schema maintenance.