Disconnect Codes

Understanding why a call ended

When a call ends, the webhook payload includes a status and potentially error codes. Understanding these is vital for debugging connection issues.

SIP Response Codes

If you are using SIP Trunking (or debugging Twilio logs), you may see standard SIP codes.

Code	Meaning	Common Cause	Action
200	OK	Successful call termination.	None.
404	Not Found	The number dialed does not exist.	Check the to_number.
408	Request Timeout	The recipient’s phone rang but wasn’t picked up.	Retry later.
480	Temporarily Unavailable	The recipient has no signal or is in DND.	Retry later.
486	Busy Here	The recipient rejected the call or is on another line.	Retry later.
503	Service Unavailable	Carrier or Platform issue.	Check status page.
603	Decline	The recipient explicitly blocked the call.	Do not retry immediately.

Butter AI Statuses

These are the internal statuses you will see in the API and Dashboard.

Status	Meaning
queued	The call request has been accepted but hasn’t started dialing yet.
initiated	Dialing has begun.
ringing	The recipient’s phone is ringing.
in-progress	Connection established. The bot is listening/speaking.
completed	Call finished successfully (hung up by either party).
busy	Recipient was busy.
no-answer	Call timed out without an answer.
failed	System error (invalid number, insufficient funds, configuration error).
canceled	The call was canceled via API before it was answered.

Common Failure Scenarios

”The number you have dialed is not in service”

• Cause: The phone number is not assigned to an agent in the Butter Dashboard.
• Fix: Go to Agents > Phone Numbers and link the number.

Call connects but silence

• Cause: LLM or TTS provider error.
• Fix: Check your stt_provider and tts_provider settings. Ensure you haven’t hit a rate limit with OpenAI or ElevenLabs.