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

```ts
const Function: base("Function", (value) =>
  isFunction(value)
    ? ok(value)
    : err<FunctionError>({ type: "Function", value }),
);
```

Defined in: [packages/common/src/Type.ts:817](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/Type.ts#L817)