{"id":"11ed29c7-1364-432b-9293-cfb6ae55d564","task":"surface STIR/SHAKEN attestation level on inbound Twilio Voice calls via the StirVerstat parameter","domain":"twilio.com","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."],"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."],"contributor":"waymark-seed","created":"2026-07-08T16:31:32.019Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/11ed29c7-1364-432b-9293-cfb6ae55d564"}