## Upload Base64

`$client->assets->uploadBase64(string content, ?string fileName, ?string mimeType): AssetUploadBase64Response`

**post** `/v1/assets/upload/base64`

Upload a file using a JSON body with base64-encoded content. Returns an uploadID that can be referenced when sending messages with attachments. Alternative to the multipart upload endpoint.

### Parameters

- `content: string`

  Base64-encoded file content (max ~500MB decoded)

- `fileName?:optional string`

  Original filename. Generated if omitted

- `mimeType?:optional string`

  MIME type. Auto-detected from magic bytes if omitted

### Returns

- `AssetUploadBase64Response`

  - `?float duration`

    Duration in seconds (audio/videos)

  - `?string error`

    Error message if upload failed

  - `?string fileName`

    Resolved filename

  - `?float fileSize`

    File size in bytes

  - `?float height`

    Height in pixels (images/videos)

  - `?string mimeType`

    Detected or provided MIME type

  - `?string srcURL`

    Local file URL (file://) for the uploaded asset

  - `?string uploadID`

    Unique upload ID for this asset

  - `?float width`

    Width in pixels (images/videos)

### Example

```php
<?php

require_once dirname(__DIR__) . '/vendor/autoload.php';

$client = new Client();

$response = $client->assets->uploadBase64(
  content: 'x', fileName: 'fileName', mimeType: 'mimeType'
);

var_dump($response);
```