Message attachments let you send files in channel messages and private messages. A message can contain text, one or more files, or both.
Sending
Use the attachment button in the chat input, choose a file, wait for the upload to finish, then send the message.
Previews
Image attachments render as inline thumbnails. Audio and video attachments use native players, PDF files expose a preview action, and other files render as safe file cards with type, size and path metadata.
Unsafe browser-rendered formats, including SVG and HTML, are kept as downloadable files instead of inline previews.
File Paths
Uploaded files are stored with a logical directory path so administrators can browse them later without depending on the storage bucket's internal object keys.
Access
Downloads are authorized by the chat server first. If access is allowed, the server redirects to a short-lived signed storage URL.
