403.
By endpoint group
Media metadata reads use
messages:read, while uploads and deletes need media:write.
A key that only sends messages referencing existing media does not need media:write.Choosing
Grant the narrowest set that works, and use separate keys for separate jobs. A key that only delivers OTPs needsmessages:send and nothing else — so if it leaks, it cannot read your conversation history.
Keys can also be restricted to specific phone numbers or IP addresses. See Authentication.