# Function: knockId()

```ts
function knockId(blob): Promise<string>;
```

Defined in: [packages/core/src/inbox/inbox.ts:210](https://github.com/leifriksheim/minca/blob/main/core/src/inbox/inbox.ts#L210)

A mailbox knock's id: the hash of its sealed blob, as relays file it

## Parameters

| Parameter | Type |
| ------ | ------ |
| `blob` | `string` |

## Returns

`Promise`\<`string`\>