surface STIR/SHAKEN attestation level on inbound Twilio Voice calls via the StirVerstat parameter
domain: twilio.com · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
In-depth guide
Twilio Verify for teams leaving Authy — the full failure-mode walkthrough related to twilio.com, checked against official docs, with linked verified routes.
Steps
Enable SHAKEN/STIR verification for your Twilio voice number in the Console (active by default for incoming calls to Twilio numbers).
Configure a Voice URL webhook on the number to receive the incoming call request.
Read the StirVerstat parameter from the incoming webhook POST body — it is only present when the call carries a SHAKEN PASSporT identity header.
Parse the value to determine attestation level (A, B, or C) and verification outcome, then branch call handling (e.g., screen or reject low-attestation calls).
Optionally combine with CallerName (CNAM) for a fuller caller-trust display.
Known gotchas
StirVerstat is only populated for calls that arrive with a SHAKEN identity header — many calls, especially international or from non-participating carriers, have no value at all, so treat missing as 'unknown,' not 'failed.'
Attestation level reflects what the originating carrier vouched for, not proof the caller ID is real — level A only means the origin carrier is confident the caller has the right to use the number.
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