Chat SDK Attachments

When someone sends an email with file attachments, the inbound message you fetch via Receiving exposes them as a list. Each attachment includes the filename, MIME type, and a way to download the content. In a Chat SDK adapter (see Chat SDK) you surface these on the message you hand to your handler.

Attachment shape

The shape below is what a custom adapter typically exposes; it mirrors the attachment metadata returned by the Receiving attachments API.

interface InboundAttachment {
  filename: string;
  contentType: string;
  url?: string;
}

Detecting and processing attachments

Read the attachment list off the inbound message (fetched with mb.emails.receiving.get in your webhook handler) and reply with the SDK.

async function onInbound(email) {
  const attachments = email.attachments ?? [];

  if (attachments.length === 0) {
    await reply(email.from, `Re: ${email.subject}`, 'Got your email — no attachments found.');
    return;
  }

  const summary = attachments
    .map((a) => `${a.filename} (${a.contentType})`)
    .join(', ');

  await reply(email.from, `Re: ${email.subject}`, `Received ${attachments.length} attachment(s): ${summary}`);
}