From b719768e7d70e18bda82030ec7e8c243e29539b2 Mon Sep 17 00:00:00 2001
From: Denys Smirnov <dennwc@pm.me>
Date: Tue, 10 Mar 2026 10:13:08 +0200
Subject: [PATCH] Allow sips: scheme in transfer URIs.

---
 .changeset/refer-sips.md |  5 +++++
 livekit/sip.go           |  6 +++---
 livekit/sip_test.go      | 20 ++++++++++++++++++++
 3 files changed, 28 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/refer-sips.md

diff --git a/.changeset/refer-sips.md b/.changeset/refer-sips.md
new file mode 100644
index 000000000..67d13b6e6
--- /dev/null
+++ b/.changeset/refer-sips.md
@@ -0,0 +1,5 @@
+---
+"@livekit/protocol": patch
+---
+
+Allow sips: scheme in transfer URIs.
diff --git a/livekit/sip.go b/livekit/sip.go
index 76c57addd..dd36d1eba 100644
--- a/livekit/sip.go
+++ b/livekit/sip.go
@@ -844,13 +844,13 @@ func (p *TransferSIPParticipantRequest) Validate() error {
 		innerURI = p.TransferTo
 	}
 
-	if !strings.HasPrefix(innerURI, "sip:") && !strings.HasPrefix(innerURI, "tel:") {
+	if !strings.HasPrefix(innerURI, "sip:") && !strings.HasPrefix(innerURI, "sips:") && !strings.HasPrefix(innerURI, "tel:") {
 		// In theory the Refer-To header can receive the full name-addr.
 		// This can make this check inaccurate, but we want to limit to just SIP and TEL URIs.
-		return errors.New("transfer_to must be a valid SIP or TEL URI (sip: or tel:)")
+		return errors.New("transfer_to must be a valid SIP(s) or TEL URI (sip:, sips: or tel:)")
 	}
 
-	if strings.HasPrefix(innerURI, "sip:") {
+	if strings.HasPrefix(innerURI, "sip:") || strings.HasPrefix(innerURI, "sips:") {
 		// addr-spec = sip:...
 		// name-addr = [ display-name ] <addr-spec>
 		// Both name-addr and addr-spec are allowed in RFC3515 (section-2.1).
diff --git a/livekit/sip_test.go b/livekit/sip_test.go
index 3353b87b5..10f27d44b 100644
--- a/livekit/sip_test.go
+++ b/livekit/sip_test.go
@@ -379,6 +379,16 @@ func TestTransferSIPParticipantRequestValidate(t *testing.T) {
 			expectError: false,
 			expectedURI: "<sip:+15105550100@sip.telnyx.com>",
 		},
+		{
+			name: "valid sips URI without brackets",
+			req: &TransferSIPParticipantRequest{
+				RoomName:            "room1",
+				ParticipantIdentity: "participant1",
+				TransferTo:          "sips:+15105550100@sip.telnyx.com",
+			},
+			expectError: false,
+			expectedURI: "<sips:+15105550100@sip.telnyx.com>",
+		},
 		{
 			name: "valid tel URI without brackets",
 			req: &TransferSIPParticipantRequest{
@@ -399,6 +409,16 @@ func TestTransferSIPParticipantRequestValidate(t *testing.T) {
 			expectError: false,
 			expectedURI: "<sip:+15105550100@sip.telnyx.com>",
 		},
+		{
+			name: "valid sips URI with brackets",
+			req: &TransferSIPParticipantRequest{
+				RoomName:            "room1",
+				ParticipantIdentity: "participant1",
+				TransferTo:          "<sips:+15105550100@sip.telnyx.com>",
+			},
+			expectError: false,
+			expectedURI: "<sips:+15105550100@sip.telnyx.com>",
+		},
 		{
 			name: "valid tel URI with brackets",
 			req: &TransferSIPParticipantRequest{