diff --git a/tracker/constants.go b/tracker/constants.go
index e55b035..a99bc07 100644
--- a/tracker/constants.go
+++ b/tracker/constants.go
@@ -66,6 +66,8 @@ const (
 	IP_ADDRESS  = "ip"
 	USERAGENT   = "ua"
 	DOMAIN_UID  = "duid"
+	DOMAIN_SID  = "sid"
+	DOMAIN_SIDX = "vid"
 	NETWORK_UID = "tnuid"
 
 	// Page View
diff --git a/tracker/subject.go b/tracker/subject.go
index 4d74472..43ca93d 100644
--- a/tracker/subject.go
+++ b/tracker/subject.go
@@ -14,6 +14,9 @@
 package tracker
 
 import (
+	"strconv"
+	"strings"
+
 	"github.com/snowplow/snowplow-golang-tracker/v3/pkg/common"
 	"github.com/snowplow/snowplow-golang-tracker/v3/pkg/payload"
 )
@@ -77,7 +80,34 @@ func (s Subject) SetDomainUserId(domainUserId string) {
 	s.payload.Add(DOMAIN_UID, common.NewString(domainUserId))
 }
 
+// SetDomainSessionId adds a domain session id to the key-value store.
+func (s Subject) SetDomainSessionId(domainSessionId string) {
+	s.payload.Add(DOMAIN_SID, common.NewString(domainSessionId))
+}
+
+// SetDomainSessionIndex adds a domain user id to the key-value store.
+func (s Subject) SetDomainSessionIndex(domainSessionIndex int) {
+	s.payload.Add(DOMAIN_SIDX, common.NewString(common.IntToString(domainSessionIndex)))
+}
+
 // SetNetworkUserId adds a network user id to the key-value store.
 func (s Subject) SetNetworkUserId(networkUserId string) {
 	s.payload.Add(NETWORK_UID, common.NewString(networkUserId))
 }
+
+// FromIdCookie sets subject fields from the ID cookie to the key-value store.
+func (s Subject) FromIdCookie(idCookie string) {
+	cookieParts := strings.Split(idCookie, ".")
+
+	if len(cookieParts) >= 6 {
+		if len(cookieParts[0]) == 36 {
+			s.SetDomainUserId(cookieParts[0])
+		}
+		if idx, err := strconv.Atoi(cookieParts[2]); err == nil {
+			s.SetDomainSessionIndex(idx)
+		}
+		if len(cookieParts[5]) == 36 {
+			s.SetDomainSessionId(cookieParts[5])
+		}
+	}
+}
diff --git a/tracker/subject_test.go b/tracker/subject_test.go
index ef2944d..51cd0c2 100644
--- a/tracker/subject_test.go
+++ b/tracker/subject_test.go
@@ -46,4 +46,11 @@ func TestSubjectSetFunctions(t *testing.T) {
 	assert.Equal("useragent-string", subjectMap[USERAGENT])
 	assert.Equal("domain-user-id", subjectMap[DOMAIN_UID])
 	assert.Equal("network-user-id", subjectMap[NETWORK_UID])
+
+	// cookie generated by JS tracker v3
+	subject.FromIdCookie("f398cb23-ec25-49cb-a30a-db942b915c2e.1662678537.839.1722486147.1722477600.7cd91831-3ed1-49dc-be81-5ab7fd2b01c3.3417ccdf-6858-4ef9-bd09-09b21e1e6ca2.46bdb481-6fc8-48c0-81bf-0d3ef64b1f0a.1722484481043.30")
+	subjectMap = subject.Get()
+	assert.Equal("f398cb23-ec25-49cb-a30a-db942b915c2e", subjectMap[DOMAIN_UID])
+	assert.Equal("839", subjectMap[DOMAIN_SIDX])
+	assert.Equal("7cd91831-3ed1-49dc-be81-5ab7fd2b01c3", subjectMap[DOMAIN_SID])
 }