[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [local‑first/Owner](https://evolu.dev/docs/api-reference/common/local-first/Owner) › OwnerUsage

Defined in: [packages/common/src/local-first/Owner.ts:453](https://github.com/evoluhq/evolu/blob/49ea8ca499566aba270f8cb601e7f49aa62320f8/packages/common/src/local-first/Owner.ts#L453)

Usage data for an [OwnerId](https://evolu.dev/docs/api-reference/common/local-first/Owner/variables/OwnerId).

Tracks storage usage to enforce quotas if needed, and some other stuff.

TODO:

- Add transferredBytes for billing and monitoring network usage.

## Properties

<a id="firsttimestamp"></a>

### firstTimestamp

```ts
readonly firstTimestamp:
  | Uint8Array<ArrayBufferLike> & Brand<"Length16"> & Brand<"TimestampBytes">
  | null;
```

Defined in: [packages/common/src/local-first/Owner.ts:474](https://github.com/evoluhq/evolu/blob/49ea8ca499566aba270f8cb601e7f49aa62320f8/packages/common/src/local-first/Owner.ts#L474)

Tracks the earliest timestamp for timestamp insertion strategies.

---

<a id="lasttimestamp"></a>

### lastTimestamp

```ts
readonly lastTimestamp:
  | Uint8Array<ArrayBufferLike> & Brand<"Length16"> & Brand<"TimestampBytes">
  | null;
```

Defined in: [packages/common/src/local-first/Owner.ts:481](https://github.com/evoluhq/evolu/blob/49ea8ca499566aba270f8cb601e7f49aa62320f8/packages/common/src/local-first/Owner.ts#L481)

Tracks the latest timestamp for timestamp insertion strategies.

Free relays can use it to identify inactive accounts for cleanup.

---

<a id="ownerid"></a>

### ownerId

```ts
readonly ownerId: Uint8Array<ArrayBufferLike> & Brand<"Length16"> & Brand<"IdBytes"> & Brand<"OwnerIdBytes">;
```

Defined in: [packages/common/src/local-first/Owner.ts:455](https://github.com/evoluhq/evolu/blob/49ea8ca499566aba270f8cb601e7f49aa62320f8/packages/common/src/local-first/Owner.ts#L455)

The [Owner](https://evolu.dev/docs/api-reference/common/local-first/Owner/interfaces/Owner) this usage data belongs to.

---

<a id="storedbytes"></a>

### storedBytes

```ts
readonly storedBytes: number & Brand<"NonNaN"> & Brand<"Finite"> & Brand<"Int"> & Brand<"NonNegative">;
```

Defined in: [packages/common/src/local-first/Owner.ts:471](https://github.com/evoluhq/evolu/blob/49ea8ca499566aba270f8cb601e7f49aa62320f8/packages/common/src/local-first/Owner.ts#L471)

Total logical data bytes stored.

Measures the size of [EncryptedDbChange](https://evolu.dev/docs/api-reference/common/local-first/Storage/type-aliases/EncryptedDbChange)s only, excluding
[Storage](https://evolu.dev/docs/api-reference/common/local-first/Storage/interfaces/Storage) implementation overhead (with SqliteStorage: indexes,
skiplist columns, etc.). This provides:

- **Predictable measurement** - same data = same byte count across all
  instances
- **Quota enforcement** - consistent billing/limits independent of storage
  implementation
- **Overhead tracking** - actual Storage size can be compared against this to
  monitor efficiency