Hello Vapi Support, We’re seeing a reliability issue on Twilio outbound calls where Twilio reports successful completed calls (SIP 200 OK, normal duration), but Vapi finalizes the call with: endedReason = call.in-progress.twilio-completed-call cost = 0 analysis/artifact = {} Vapi call logs and Vapi API logs: empty (logsCount=0) Webhook deliveries to our server are successful (HTTP 200). Each affected call shows webhook sequence: status-update status=in-progress status-update status=ended with endedReason varying (assistant-ended-call / voicemail / customer-ended-call / assistant-said-end-call-phrase) end-of-call-report with endedReason=call.in-progress.twilio-completed-call, cost=0, empty artifacts This suggests Twilio PSTN leg is connecting, but Vapi’s AI media/pipeline is not attaching/initializing (or is tearing down early) while Twilio continues and later completes the call. Example Twilio evidence: Twilio Call SID CA0b6b2046c0acfdaa5be3c35664f35fc3 (corresponding Vapi call 019d900c-c7cf-7000-82d0-0fdd1d94ce64) shows: Duration 44s, Last SIP Response 200 OK, no jitter/packet loss flags, status completed, caller hung up. Affected calls (Vapi Call ID → Twilio Call SID): 019d900c-c7cf-7000-82d0-0fdd1d94ce64 → CA0b6b2046c0acfdaa5be3c35664f35fc3 019d900c-a5be-7ee6-a47e-573364aa4bb4 → CA0b19853d25eb6abbc2409f91856e24bc 019d900d-6d0c-711e-8789-ffca23bb5eb0 → CA0b88e64b817c2132bec04dcfd4d531fb 019d900d-6c2e-711e-8789-eb2704ee91fc → CAc7f339b75028dedc4a51f0435e7a3c3b There is much more and only attaching this 4 due to character limit Request: Please investigate internal telephony/media attach traces for these call IDs—why can Twilio have an answered completed call while Vapi reports cost=0 and no artifacts? Is there a known failure mode/race condition where the Twilio call continues after Vapi runtime detaches? Recommended configuration changes or platform fix to prevent these “ghost completed” AI-less calls.

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To address "ghost completed" calls with

call.in-progress.twilio-completed-call

, double-check your assistant and workflow configuration for missing required fields, as configuration errors can cause the AI pipeline not to attach. For a quick check, review your assistant settings in the Vapi dashboard and ensure all required fields are filled:

text
1. Go to your assistant/workflow in the Vapi dashboard.
2. Verify all required fields (assistant ID, phone number ID, etc.) are set.
3. Save and redeploy if any changes are made.

This step helps prevent calls where Twilio completes but Vapi does not process the AI leg. For persistent issues, review [call ended reasons](https://docs.vapi.ai/calls/call-ended-reason) and consider reaching out to Vapi support with call IDs for deeper investigation. Source: - [Call ended reasons](https://docs.vapi.ai/calls/call-ended-reason)

@Vapi Support Bot There are multiple calls from the same number on that same day without any error. So it's definitely not a configuration issue.

Since configuration issues are ruled out, the best next step is to escalate the affected call IDs to Vapi support for internal investigation. Prepare a list of problematic call IDs and submit them via the [Vapi support portal](https://docs.vapi.ai/issue-reporting) with a brief description:

text
Call IDs: [list your affected call IDs]
Issue: Intermittent "ghost completed" calls—Twilio completes, but Vapi shows `call.in-progress.twilio-completed-call` with no artifacts.

This will help the support team analyze backend logs and identify any platform-level issues. Sources: - [Call ended reasons](https://docs.vapi.ai/calls/call-ended-reason) - [How to report issues effectively](https://docs.vapi.ai/issue-reporting) - [Discord: Vapi outbound call not triggering](https://discord.com/channels/1211482211119796234/1372358449761091584)

Posted a detailed email to support@vapi.ai on Apr 20 and still no response other than the bot. I am looking for a permanent solution for errors like "call.in-progress.twilio-completed-call". This is still happening for random calls and it cannot be tolerated.