Durable State and WebSockets

Imported from "void/durable". See Durable State for the complete file convention and deployment support.

defineDurableState(definition)

Defines a typed, persisted Durable Object state machine. The returned object must be the default export of a module under durable-objects/; named-export the same object for typed RPC calls elsewhere in the app.

function defineDurableState<TState, TEnv, TMethods>(definition: {
  name?: string;
  initialState: TState | ((env: TEnv) => TState | Promise<TState>);
  version?: number;
  migrations?: Array<{
    version: number;
    migrate(state: unknown): TState | Promise<TState>;
  }>;
  methods: TMethods;
  fetch?: (context, request: Request) => Response | Promise<Response>;
  alarm?: (context) => void | Promise<void>;
  storageKey?: string;
}): DurableStateApi<TMethods>;

DurableStateApi exposes class, get(name), get(namespace, name), getById(id), and getById(namespace, id). Stubs returned by the lookup helpers contain the definition's methods with their argument types preserved and return values wrapped in Promise.

name optionally fixes the persistent resource identity instead of deriving it from the filename. Run void info and pin the displayed name before renaming a deployed definition. Keep instance names passed to get() unchanged. See the migration flow.

WebSockets

Imported from "void/ws". defineRoom() adds shared-room helpers to hook contexts; defineWebSocket() supplies a connection's socket helpers. Both require messages.client and messages.server Standard Schema validators and support the hooks described in the WebSocket guide.

Both helpers accept these optional resource settings:

name?: string;
key?: (context: { params: Record<string, string> }) => string;

name fixes the Worker class and binding identity. Without it, Void derives the identity from the route file. Run void info before moving a deployed route and pin its displayed name.

key selects the route instance and its ctx.id. Without it, routes use parameter names and values in route order (room=general, or default without parameters). A callback must return a stable string synchronously. When renaming parameters, preserve the complete old key to retain state. See moving routes and renaming parameters.