---

name: effect-schema description: Define Effect schemas that are verified against domain types. Use when authoring or updating Effect Schema definitions, or when the user mentions schema/type parity, satisfies, or tsafe Equals checks.

Effect Schema Type Parity

Instructions

• Define the domain type first (prefer interface), then define the schema and assert parity.
• Always use satisfies Schema.Schema<YourType, any> on the schema.
• Add assert<Equals<typeof YourSchema.Type, Readonly<YourType>>>() using tsafe.
• If the assert<Equals<...>> isn't typed correctly but the satisfies is, you can optionally add the _check1/_check2 assignments with void (see ZerospinCommandSchema).
• When validating unknown input against an Effect schema, prefer validateUnknown from zerospin if available.

Example

import type { Equals } from 'tsafe';

import { Schema } from 'effect';
import { assert } from 'tsafe';

export interface IFoo {
  bar: string;
}

export const ZFoo = Schema.Struct({
  bar: Schema.String,
}) satisfies Schema.Schema<IFoo, any>;

const _check1: typeof ZFoo.Type = {} as IFoo;
const _check2: IFoo = {} as typeof ZFoo.Type;
void _check1;
void _check2;
assert<Equals<typeof ZFoo.Type, Readonly<IFoo>>>();