All messaging endpoints support sending attachments. You can include either one or multiple attachments in one of two formats:
  1. HTTPS URL: We’ll download the attachment from the provided URL. This is the easiest method, but requires you to serve your files over the internet.
  2. Media Library URI: Use this feature when you need to upload files directly using the media_library:// protocol.

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Using the Media Library

First, create a signed upload URL with the path to your file: 
const response = await api.request(
  `/storage/upload/sign/media_library/test.png`,
  {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${API_KEY}`,
    },
  }
);

const url = await response.text();
The file will be uploaded to test.png. You can also upload to nested paths, for example /storage/upload/sign/media_library/my-dir/test.png. This will create an upload URL for my-dir/test.png. Next, upload your file using the signed URL: 
const res = await fetch(url, {
  method: 'PUT',
  body: Buffer.from(BASE_64_IMAGE, 'base64'),
  headers: { 'Content-Type': 'image/png' },
});
Media library files are automatically deleted after 30 days. Until then, you can use them as often as needed when sending messages or broadcasts by passing them as attachments:
  • attachments: ["media_library://test.png"]
  • attachments: ["media_library://my-dir/test.png"]