40300 — not_member

The user is authenticated but not a member of this room. Terminal until they are invited or join.

At a glance — HTTP 403 · close 1008 not_member · terminal · SDK FluxyNotMemberError.

What to do

• Add the user to the room (invite / membership API), or connect with an identity that is already a member.
• The SDK also maps a Forbidden close reason to FluxyNotMemberError — inspect the raw reason when you need to tell the two apart.
• Do not auto-retry the same identity: reconnect fails until membership changes.

Related

• 40301 banned
• 40302 forbidden
• 40108 auth_refused