# SyncAdapterOptions

Import it from `@grafloria/engine`.

```ts
interface SyncAdapterOptions
```

**Properties**

| Name | Type | Default | Description |
| --- | --- | --- | --- |
| `batch?` | `Omit<OpBatcherOptions, 'onFlush'> \| false` |  | Batching. `false` sends every op the instant it happens — legal, and a bad idea. |
| `relay?` | `boolean` |  | Forward ops that were NEW to us on to our other peers. |
| `syncIntervalMs?` | `number` |  | Periodic anti-entropy, ms. 0 disables it (the tests drive `sync()` by hand). |
| `heartbeatMs?` | `number` |  | Re-publish our awareness this often, so peers do not time us out while we sit still. Default: a third of {@link awarenessTimeoutMs} (5 s with the defaults). 0 turns the heartbeat off; peers then expire anyone silent for the timeout, idle or not. |
| `awarenessThrottleMs?` | `number` |  | Minimum ms between awareness sends. 60Hz in, ~20Hz out. |
| `awarenessTimeoutMs?` | `number` |  | Drop a peer's presence (its cursor, selection and name) after this long without a word from it. Default 15 s. Checked on a timer, so a peer that crashes without saying goodbye is removed within about the timeout plus a third of it. A peer that leaves cleanly is removed at once. |
| `setTimer?` | `(cb: () => void, ms: number) => unknown` |  | Injectables, so every timing test is deterministic instead of a race. |
| `clearTimer?` | `(handle: unknown) => void` |  |  |
| `setInterval?` | `(cb: () => void, ms: number) => unknown` |  |  |
| `clearInterval?` | `(handle: unknown) => void` |  |  |
| `now?` | `() => number` |  |  |