# grantDescriptor

> **grantDescriptor**(`ref`, `node`): [`GrantDescriptor`](/reference/filoz/keysmith/interfaces/grantdescriptor/)

Defined in: [derive.ts:339](https://github.com/FilOzone/synapse-sdk/blob/68e30a2a5457180e60a5579eb5ecff90b65894b3/packages/keysmith/src/derive.ts#L339)

The descriptor naming what a grant unlocks, ready for `wrapTo()`.

Build descriptors with `grantDescriptor()` rather than filling the
structure by hand: the descriptor is authenticated as the grant's AAD and
compared byte for byte, so the owner is lowercased and the keyspace is
spelled exactly as the envelope spells it.

## Parameters

| Parameter | Type |
| ------ | ------ |
| `ref` | [`KeyspaceRef`](/reference/filoz/keysmith/interfaces/keyspaceref/) |
| `node` | [`GrantNode`](/reference/filoz/keysmith/type-aliases/grantnode/) |

## Returns

[`GrantDescriptor`](/reference/filoz/keysmith/interfaces/grantdescriptor/)