EventDef

EventDef<TName, TType, TEncoded, TDerived> = object

Defined in: packages/@livestore/common/dist/schema/EventDef/event-def.d.ts:30

Core type representing an event definition in LiveStore.

An EventDef defines the structure and behavior of an event type, including:

A unique name identifying the event type (conventionally versioned, e.g., v1.TodoCreated)
A schema for validating and encoding/decoding event arguments
Options controlling sync behavior and constraints

EventDefs are callable - invoking them creates a partial event object suitable for store.commit().

Example

import { Events } from '@livestore/livestore'
import { Schema } from 'effect'

const todoCreated = Events.synced({
  name: 'v1.TodoCreated',
  schema: Schema.Struct({
    id: Schema.String,
    text: Schema.String,
  }),
})

// Use the EventDef as a constructor
store.commit(todoCreated({ id: 'abc', text: 'Buy milk' }))

Type Parameters

TName

TName extends string

TType

TType

TEncoded

TEncoded = TType

TDerived

TDerived extends boolean = false

EventDef(args): object

Defined in: packages/@livestore/common/dist/schema/EventDef/event-def.d.ts:53

Callable signature - creates a partial event with decoded arguments. The returned object can be passed directly to store.commit().

Parameters

args

TType

Returns

object

args

args: TType

name

name: TName

Properties

encoded()

encoded: (args) => object

Defined in: packages/@livestore/common/dist/schema/EventDef/event-def.d.ts:61

Creates a partial event with pre-encoded arguments. Useful when working with already-serialized data.

Parameters

args

TEncoded

Returns

object

args

args: TEncoded

name

name: TName

Event

readonly Event: object

Defined in: packages/@livestore/common/dist/schema/EventDef/event-def.d.ts:66

Type helper for accessing the event’s shape with name and decoded args.

args

args: TType

name

name: TName

name

name: TName

Defined in: packages/@livestore/common/dist/schema/EventDef/event-def.d.ts:32

Unique identifier for this event type. Conventionally versioned (e.g., v1.TodoCreated).

options

options: object

Defined in: packages/@livestore/common/dist/schema/EventDef/event-def.d.ts:35

clientOnly

clientOnly: boolean

When true, the event is only synced within the same client’s sessions (e.g., across tabs) but never sent to the sync backend. Useful for UI state like selected items or filters.

derived

derived: TDerived

Whether this is a derived event. Derived events cannot have materializers.

facts

facts: FactsCallback<TType> | undefined

Callback defining fact constraints for this event. This feature is not fully implemented yet.

schema

schema: Schema.Schema<TType, TEncoded>

Defined in: packages/@livestore/common/dist/schema/EventDef/event-def.d.ts:34

Effect Schema used for validating and encoding/decoding event arguments.