[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:416](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/local-first/Owner.ts#L416)

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:437](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/local-first/Owner.ts#L437)

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:444](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/local-first/Owner.ts#L444)

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:418](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/local-first/Owner.ts#L418)

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<"Int"> & Brand<"NonNegative">;
```

Defined in: [packages/common/src/local-first/Owner.ts:434](https://github.com/evoluhq/evolu/blob/e7144e2bbe9069362b62dec1b64a8aa922b8f1b0/packages/common/src/local-first/Owner.ts#L434)

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