[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Worker](https://evolu.dev/docs/api-reference/common/Worker) › MessagePort

Defined in: [packages/common/src/Worker.ts:46](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Worker.ts#L46)

Platform-agnostic MessagePort.

Note: There is no reliable way to detect when a port is closed or
disconnected. Calling `postMessage` on a disposed port does not throw — it
silently fails. To detect dead ports, use a heartbeat pattern where the other
end periodically sends "alive" messages and stale ports are pruned after a
timeout.

## See

https://developer.mozilla.org/en-US/docs/Web/API/MessagePort

## Extends

- [`Disposable`](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-5-2.html#using-declarations-and-explicit-resource-management)

## Extended by

- [`Worker`](https://evolu.dev/docs/api-reference/common/Worker/interfaces/Worker)
- [`WorkerSelf`](https://evolu.dev/docs/api-reference/common/Worker/interfaces/WorkerSelf)

## Methods

<a id="dispose"></a>

### \[dispose\]()

```ts
dispose: void;
```

Defined in: node_modules/.bun/typescript@5.9.3/node_modules/typescript/lib/lib.esnext.disposable.d.ts:36

#### Inherited from

```ts
Disposable.[dispose]
```

## Properties

<a id="native"></a>

### native

```ts
readonly native: NativeMessagePort<Input, Output>;
```

Defined in: [packages/common/src/Worker.ts:72](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Worker.ts#L72)

The native underlying port for transferring via `postMessage`.

### Example

```ts
sharedWorker.port.postMessage(
  { type: "InitConsole", port: consoleChannel.port1.native },
  [consoleChannel.port1.native],
);
```

---

<a id="onmessage"></a>

### onMessage

```ts
onMessage: ((message: Output) => void) | null;
```

Defined in: [packages/common/src/Worker.ts:58](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Worker.ts#L58)

Handler for incoming messages. Messages are queued until this is assigned,
matching native `MessagePort` behavior where setting `onmessage` implicitly
calls `start()`. This enables safe async initialization — the sender can
post messages immediately while the receiver sets up.

---

<a id="postmessage"></a>

### postMessage

```ts
readonly postMessage: (message: Input, transfer?: readonly Transferable[]) => void;
```

Defined in: [packages/common/src/Worker.ts:47](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Worker.ts#L47)