Blind transfer: Pure in-dialog SIP REFER with Refer-To header via SIP.js over WSS :9002 (CORS-safe), or POST /ns-api/ with object: "call", action: "transfer", or REST PATCH .../transfer (Desktop/Mobile). Attended transfer: Leg 1 held, Leg 2 established, then SIP REFER with Replaces header via SIP.js over WSS :9002, or POST /ns-api/ with object: "call", action: "transfer".

LIVEDOCCODE Edge supports today · Phase 3

Caveat: Pure SIP REFER is standard, native, and completely immune to browser REST CORS method restrictions. Attended transfer requires softphone to maintain two concurrent SIP dialogs.