## Upload Base64

**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.

### Body 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

- `duration: optional number`

  Duration in seconds (audio/videos)

- `error: optional string`

  Error message if upload failed

- `fileName: optional string`

  Resolved filename

- `fileSize: optional number`

  File size in bytes

- `height: optional number`

  Height in pixels (images/videos)

- `mimeType: optional string`

  Detected or provided MIME type

- `srcURL: optional string`

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

- `uploadID: optional string`

  Unique upload ID for this asset

- `width: optional number`

  Width in pixels (images/videos)

### Example

```http
curl http://localhost:23373/v1/assets/upload/base64 \
    -H 'Content-Type: application/json' \
    -d '{
          "content": "x"
        }'
```