Create a download URL

GET/chat-rooms/:roomId/files/:fileId/url

Files are private, so fetch a short-lived URL each time. disposition=inline is honoured only for allowed types such as PDF; anything else is forced to attachment. The URL carries the file name, so opening it as a link downloads the file.

Auth	Login required

Path parameters

roomIdstringrequired

Chat room ID.

fileIdstringrequired

File ID.

Query parameters

dispositionstringoptional

attachment (default) or inline.

Response

Field	Type	Description
`url`	string	Pre-signed URL for the file.
`expiresIn`	number	Lifetime of the URL in seconds.
`expiresAt`	string	Expiry time of the URL (ISO 8601).
`fileName / mimeType / size`	mixed	File name, MIME type and size in bytes.
`disposition`	'inline' \| 'attachment'	How the browser should open it; inline for PDFs and images.

Request

curl https://api.4s.link/chat-rooms/ROOM_ID/files/FILE_ID/url \
  -H "Authorization: Bearer 4s_at_..."

Example response

{
  "url": "https://.../chat-files/...?X-Amz-Signature=...",
  "expiresIn": 300,
  "expiresAt": "2026-08-29T00:05:00.000Z",
  "fileName": "report.pdf",
  "mimeType": "application/pdf",
  "size": 1234567,
  "disposition": "inline"
}