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

## Call Signature

```ts
function createRefCountByKey<TKey>(): RefCountByKey<TKey>;
```

Defined in: [packages/common/src/RefCount.ts:108](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/RefCount.ts#L108)

Creates [RefCountByKey](https://evolu.dev/docs/api-reference/common/RefCount/interfaces/RefCountByKey).

## Call Signature

```ts
function createRefCountByKey<TKey, L>(
  options: CreateRefCountByKeyOptions<TKey, L>,
): RefCountByKey<TKey>;
```

Defined in: [packages/common/src/RefCount.ts:109](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/RefCount.ts#L109)

Creates [RefCountByKey](https://evolu.dev/docs/api-reference/common/RefCount/interfaces/RefCountByKey).