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Twilio is not a voice-agent provider, and connecting it does not bring calls into Zelto. It is an enrichment connection: most voice platforms — Vapi, Retell, ElevenLabs, LiveKit — place their PSTN legs over Twilio, and Twilio sees a layer of the call they never report. Connect your Twilio account and Zelto attaches that layer to calls you are already ingesting. Keep your voice provider connected. Twilio sits alongside it.

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What it adds

For each call Zelto can match to a Twilio call, the connection adds:
  • Ring time and post-dial delay — how long the callee’s phone rang before anyone answered, and how long the carrier took to start ringing at all.
  • Who hung up — whether the caller, the callee, or the platform ended the call. A transcript that stops mid-sentence looks the same either way; this says which it was.
  • Packet loss and jitter — the media-quality counters for each edge of the call, so “the agent kept talking over the customer” can be separated from “the audio was breaking up”.
  • Carrier and country of the callee — which network the number lives on and where it is, useful when failures cluster on one carrier or one country.
These land on the call alongside everything else Zelto records — see Traces and Conversations.

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Before you connect

Twilio’s quality and disconnect data comes from Voice Insights Advanced Features, which is off by default. Enable it in the Twilio Console under Voice → Settings → Voice Insights before connecting, or the connection will succeed and find nothing to read.

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Connect

  1. Open Settings → Integrations → Twilio and click Connect.
  2. Give the connection a label (e.g. Production) so you can tell multiple Twilio accounts apart.
  3. Paste your Account SID and Auth Token. Both are on the Twilio Console dashboard under Account Info. Zelto validates the pair against the Twilio account before saving, then stores it encrypted.
You can connect multiple Twilio accounts to one organization — useful when different agents or regions bill to different subaccounts.

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What Zelto reads

Zelto reads three read-only resources, per call, and nothing else: Zelto never places calls, never modifies your Twilio configuration, and never reads call recordings from Twilio.

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Limits worth knowing

  • It only applies going forward. Voice Insights is not retroactive: calls placed before the feature was enabled on your Twilio account never get a summary, no matter when you connect. Calls already in Zelto are not enriched in hindsight.
  • Twilio keeps 30 days. Past that window Twilio stops serving the summary, so enrichment has to happen while the call is recent. What Zelto already captured is kept.
  • No MOS score. Twilio does not compute a Mean Opinion Score for this call topology, so Zelto does not show one. Packet loss and jitter are what is available.
  • A summary takes a few minutes. Twilio finishes processing roughly 10–30 minutes after a call ends, so enrichment trails the call itself.

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Connection status & disconnecting

The Twilio card lists each connected account. Disconnect removes that account’s stored credentials. Enrichment stops for future calls; everything already attached to past calls is kept, and your voice provider connection is untouched.