@hamstore/event-type-standard-schema

DRY Hamstore EventType definition using Standard Schema with runtime validation.

Installation

# npm
npm install @hamstore/event-type-standard-schema

# yarn
yarn add @hamstore/event-type-standard-schema

# pnpm
pnpm add @hamstore/event-type-standard-schema

You also need a Standard Schema-compatible validation library as a peer dependency, for example:

• Zod (v3.25+ or v4+)
• Valibot
• ArkType

Usage

import { StandardSchemaEventType } from '@hamstore/event-type-standard-schema';
import { z } from 'zod'; // or valibot, arktype, etc.

const pokemonCaughtEventType = new StandardSchemaEventType({
  type: 'POKEMON_CAUGHT',
  payloadSchema: z.object({
    pokemonId: z.string(),
    pokemonName: z.string(),
    level: z.number().int().positive(),
  }),
  metadataSchema: z.object({
    trainerName: z.string(),
  }),
});

The StandardSchemaEventType extends the core EventType and provides a parseEventDetail method that validates event payloads and metadata at runtime using the Standard Schema validate interface.

Validation

When used with an EventStore, validation is triggered by the validate option on pushEvent and groupEvent:

// Validates if the event type has a parser (default: 'auto')
await eventStore.pushEvent(eventDetail, { validate: 'auto' });

// Always validate, throws if no parser defined
await eventStore.pushEvent(eventDetail, { validate: true });

// Skip validation
await eventStore.pushEvent(eventDetail, { validate: false });

Why Standard Schema?

Standard Schema is a shared interface implemented by multiple validation libraries. Using @hamstore/event-type-standard-schema means your event types work with any Standard Schema-compatible library, without library-specific adapters.

This package is the recommended replacement for @hamstore/event-type-zod.