Twilio Account SID (AC…). Always required (used directly, or as the accountSid option under API-key auth).
OptionalApiAPI Key secret — paired with ApiKeySid.
OptionalApiAPI Key SID (SK…) — preferred over the auth token for REST auth when present (with ApiKeySecret).
OptionalAuthAccount auth token — used when no API key pair is supplied. Also the HMAC key for webhook signature verification.
Credentials the REST client constructs the
twilioSDK with. Resolved upstream via MJ config — never inlined.