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

Defined in: [packages/common/src/local-first/Protocol.ts:355](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/local-first/Protocol.ts#L355)

Parsed protocol header for supported protocol messages.

## Extends

- [`Typed`](https://evolu.dev/docs/api-reference/common/Type/interfaces/Typed)\<`"ProtocolHeader"`\>

## Properties

<a id="messagetype"></a>

### messageType

```ts
readonly messageType: MessageType;
```

Defined in: [packages/common/src/local-first/Protocol.ts:358](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/local-first/Protocol.ts#L358)

---

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

### ownerId

```ts
readonly ownerId: string & Brand<"Id"> & Brand<"OwnerId">;
```

Defined in: [packages/common/src/local-first/Protocol.ts:357](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/local-first/Protocol.ts#L357)

---

<a id="type"></a>

### type

```ts
readonly type: "ProtocolHeader";
```

Defined in: [packages/common/src/Type.ts:11986](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/Type.ts#L11986)

#### Inherited from

[`Typed`](https://evolu.dev/docs/api-reference/common/Type/interfaces/Typed).[`type`](https://evolu.dev/docs/api-reference/common/Type/interfaces/Typed#type)

---

<a id="version"></a>

### version

```ts
readonly version: 1;
```

Defined in: [packages/common/src/local-first/Protocol.ts:356](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/local-first/Protocol.ts#L356)