I’m facing an issue with my VAPI workflow while using Twilio as SIP. The workflow stops working after 2–3 minutes, but the actual call on the SIM/Twilio side continues to run. After the workflow stops, there is no response from the other side, even though the call is still active. Setup details: - VAPI workflow - Twilio used as SIP provider - Call remains connected, but workflow execution ends - No audio/response after workflow stops Could you please help identify why the workflow stops while the call is still running, or if there are any timeout/keep-alive settings that need to be adjusted? Thanks. #1211483291191083018

Hi M Fazeel, Please check these likely causes and steps: 1. Confirm endedReason in the call object • GET https://api.vapi.ai/call/{call_id} and check

endedReason

. If it's not

assistant-forwarded-call

or shows a pipeline/worker error (e.g.,

call.in-progress.error-vapifault-*

or

worker-shutdown

), that explains the workflow ending. Docs: https://docs.vapi.ai/calls/call-ended-reason 1. Workflow time limits • Workflows enforce a 10‑minute engine limit (see related thread). If you’re using a Visual Workflow, it may stop earlier due to internal limits. If you need >10 minutes, run the flow as an Assistant (supports longer maxCallDurationSeconds). See troubleshooting note in threads. 1. SIP/Twilio provider handling • Vapi may hand off SIP control to Twilio. If Vapi stops executing but Twilio keeps the PSTN leg alive, audio/response will stop. Check the Vapi call object for

phoneCallProviderBypassEnabled

and

phoneCallProviderId

. If bypass is true you’re responsible for call control. See transfer/forwarding guide: https://docs.vapi.ai/phone-calling/in-call-control/transfer-calls/debug-forwarding-drops 1. Telephony provider logs • Use the telephony call ID from the Vapi call and inspect Twilio Call Logs/TwiML execution for disconnects or errors (search CallSid). Docs: https://docs.vapi.ai/phone-calling/in-call-control/transfer-calls/debug-forwarding-drops and Twilio SIP guide: https://docs.vapi.ai/advanced/sip/twilio 1. Worker/keep‑alive or pipeline failures • If Vapi workers or pipeline fail mid-call (e.g.,

call.in-progress.error-vapifault-worker-not-available

), the workflow can stop while Twilio keeps the leg. Check call logs for pipeline/worker errors and timestamps; correlate with any service outages.