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

```ts
type Mutable<T> = { -readonly [P in keyof T]: T[P] };
```

Defined in: [packages/common/src/Types.ts:181](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Types.ts#L181)

Removes `readonly` modifier from all properties of a type.

Useful for constructing immutable objects step-by-step (e.g. builder pattern)
before casting them back to the readonly type.