# UseUploadPiecesProps

Defined in: [synapse-react/src/warm-storage/use-upload-pieces.ts:73](https://github.com/FilOzone/synapse-sdk/blob/628d3a8812e8612a183a3abe3328169fb741260b/packages/synapse-react/src/warm-storage/use-upload-pieces.ts#L73)

The props for the useUploadPieces hook.

## Extends

- [`SessionKeySignerOptions`](/reference/filoz/synapse-react/interfaces/sessionkeysigneroptions/)

## Properties

### concurrency?

> `optional` **concurrency?**: `number`

Defined in: [synapse-react/src/warm-storage/use-upload-pieces.ts:79](https://github.com/FilOzone/synapse-sdk/blob/628d3a8812e8612a183a3abe3328169fb741260b/packages/synapse-react/src/warm-storage/use-upload-pieces.ts#L79)

The maximum number of files streamed to the provider at the same time.

#### Default

```ts
4
```

***

### mutation?

> `optional` **mutation?**: [`Omit`](https://www.typescriptlang.org/docs/handbook/utility-types.html#omittype-keys)\<`MutateOptions`\<[`UseUploadPiecesResult`](/reference/filoz/synapse-react/interfaces/useuploadpiecesresult/), [`Error`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error), [`UseUploadPiecesVariables`](/reference/filoz/synapse-react/interfaces/useuploadpiecesvariables/), `unknown`\>, `"mutationFn"`\>

Defined in: [synapse-react/src/warm-storage/use-upload-pieces.ts:91](https://github.com/FilOzone/synapse-sdk/blob/628d3a8812e8612a183a3abe3328169fb741260b/packages/synapse-react/src/warm-storage/use-upload-pieces.ts#L91)

The mutation options.

***

### onFileProgress?

> `optional` **onFileProgress?**: (`progress`) => `void`

Defined in: [synapse-react/src/warm-storage/use-upload-pieces.ts:83](https://github.com/FilOzone/synapse-sdk/blob/628d3a8812e8612a183a3abe3328169fb741260b/packages/synapse-react/src/warm-storage/use-upload-pieces.ts#L83)

The callback to call when a file makes upload progress.

#### Parameters

| Parameter | Type |
| ------ | ------ |
| `progress` | [`UploadPiecesFileProgress`](/reference/filoz/synapse-react/interfaces/uploadpiecesfileprogress/) |

#### Returns

`void`

***

### onHash?

> `optional` **onHash?**: (`hash`) => `void`

Defined in: [synapse-react/src/warm-storage/use-upload-pieces.ts:87](https://github.com/FilOzone/synapse-sdk/blob/628d3a8812e8612a183a3abe3328169fb741260b/packages/synapse-react/src/warm-storage/use-upload-pieces.ts#L87)

The callback to call when an add-pieces transaction hash is available.

#### Parameters

| Parameter | Type |
| ------ | ------ |
| `hash` | `string` |

#### Returns

`void`

***

### sessionKey?

> `optional` **sessionKey?**: [`SessionKey`](/reference/filoz/synapse-core/session-key/interfaces/sessionkey/)\<`"Secp256k1"`\> \| `null`

Defined in: [synapse-react/src/signer.ts:14](https://github.com/FilOzone/synapse-sdk/blob/628d3a8812e8612a183a3abe3328169fb741260b/packages/synapse-react/src/signer.ts#L14)

The session key to sign storage provider (EIP-712) operations with.
If not provided, the connected wallet signs.

#### Inherited from

[`SessionKeySignerOptions`](/reference/filoz/synapse-react/interfaces/sessionkeysigneroptions/).[`sessionKey`](/reference/filoz/synapse-react/interfaces/sessionkeysigneroptions/#sessionkey)