Thanks — I understand you're trying to use a dispatch rule to create rooms for inbound SIP calls, and you're seeing: Error Message: failed joining room: cannot create LiveKit participant: not found You're asking whether "Automatically create room on participant join" must be enabled or whether dispatch rules alone should create the room. Short answer • You should enable "Automatically create room on participant join". Dispatch rules rely on LiveKit's dynamic room-creation-on-join behavior, so disabling that option prevents the SIP participant from creating/joining the room and produces the error you saw. Why this happens • When an inbound SIP call is routed, the dispatch rule supplies the room name (via

room_prefix

or

room_name

) and attempts to add the SIP participant to that room. • LiveKit requires the ability to create the room at the time the participant joins. If automatic room creation is turned off, the participant cannot create the room and the join fails with the "not found" participant/room error. • There is no separate “SIP-only” bypass for room creation — auto-create must be allowed for dispatch-rule-created rooms to work. What to do now 1. Enable Automatically create room on participant join in your LiveKit project settings. 2. Confirm your dispatch rule includes the correct

room_prefix

or

room_name

. 3. Verify any agents referenced in

room_config.agents

are configured and available (if you dispatch agents). 4. Retry the inbound call flow. If you still see the same error after enabling auto-create, tell me: • The dispatch rule snippet (room_name/room_prefix) you’re using (redact secrets). • Any relevant room_config or agent names. • Exact timestamps of a failing call (so I can help trace it). I can then help check the routing and room-creation steps with you. Sources: sip | livekit/livekit_composite | DeepWiki | Accepting calls overview | LiveKit Documentation | Agents telephony integration | LiveKit Documentation