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

```ts
type OnlyDone<E> = Extract<E, Done<any>>;
```

Defined in: [packages/common/src/Result.ts:510](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Result.ts#L510)

Extracts only [Done](https://evolu.dev/docs/api-reference/common/Result/interfaces/Done) from an error union.

Useful for pull-based protocols where completion is encoded in the error
channel (for example [NextResult](https://evolu.dev/docs/api-reference/common/Result/type-aliases/NextResult)).