diff --git a/SessionMessagingKit/Messages/Control Message/ClosedGroupUpdate.swift b/SessionMessagingKit/Messages/Control Message/ClosedGroupUpdate.swift
index f5d863130..0cf32e6c8 100644
--- a/SessionMessagingKit/Messages/Control Message/ClosedGroupUpdate.swift	
+++ b/SessionMessagingKit/Messages/Control Message/ClosedGroupUpdate.swift	
@@ -1,5 +1,129 @@
+import SessionUtilities
+import SessionProtocolKit
 
 @objc(SNClosedGroupUpdate)
 public final class ClosedGroupUpdate : ControlMessage {
+    public var kind: Kind?
 
+    // MARK: Kind
+    public enum Kind {
+        case new(groupPublicKey: Data, name: String, groupPrivateKey: Data, senderKeys: [ClosedGroupSenderKey], members: [Data], admins: [Data])
+        case info(groupPublicKey: Data, name: String, senderKeys: [ClosedGroupSenderKey], members: [Data], admins: [Data])
+        case senderKeyRequest(groupPublicKey: Data)
+        case senderKey(groupPublicKey: Data, senderKey: ClosedGroupSenderKey)
+    }
+
+    // MARK: Initialization
+    init(kind: Kind) {
+        super.init()
+        self.kind = kind
+    }
+
+    // MARK: Coding
+    public required init?(coder: NSCoder) {
+        super.init(coder: coder)
+        guard let groupPublicKey = coder.decodeObject(forKey: "groupPublicKey") as? Data,
+            let rawKind = coder.decodeObject(forKey: "kind") as? String else { return }
+        switch rawKind {
+        case "new":
+            guard let name = coder.decodeObject(forKey: "name") as? String,
+                let groupPrivateKey = coder.decodeObject(forKey: "groupPrivateKey") as? Data,
+                let senderKeys = coder.decodeObject(forKey: "senderKeys") as? [ClosedGroupSenderKey],
+                let members = coder.decodeObject(forKey: "members") as? [Data],
+                let admins = coder.decodeObject(forKey: "admins") as? [Data] else { return }
+            self.kind = .new(groupPublicKey: groupPublicKey, name: name, groupPrivateKey: groupPrivateKey, senderKeys: senderKeys, members: members, admins: admins)
+        case "info":
+            guard let name = coder.decodeObject(forKey: "name") as? String,
+                let senderKeys = coder.decodeObject(forKey: "senderKeys") as? [ClosedGroupSenderKey],
+                let members = coder.decodeObject(forKey: "members") as? [Data],
+                let admins = coder.decodeObject(forKey: "admins") as? [Data] else { return }
+            self.kind = .info(groupPublicKey: groupPublicKey, name: name, senderKeys: senderKeys, members: members, admins: admins)
+        case "senderKeyRequest":
+            self.kind = .senderKeyRequest(groupPublicKey: groupPublicKey)
+        case "senderKey":
+            guard let senderKeys = coder.decodeObject(forKey: "senderKeys") as? [ClosedGroupSenderKey],
+                let senderKey = senderKeys.first else { return }
+            self.kind = .senderKey(groupPublicKey: groupPublicKey, senderKey: senderKey)
+        default: return
+        }
+    }
+
+    public override func encode(with coder: NSCoder) {
+        super.encode(with: coder)
+        guard let kind = kind else { return }
+        switch kind {
+        case .new(let groupPublicKey, let name, let groupPrivateKey, let senderKeys, let members, let admins):
+            coder.encode("new", forKey: "kind")
+            coder.encode(groupPublicKey, forKey: "groupPublicKey")
+            coder.encode(name, forKey: "name")
+            coder.encode(groupPrivateKey, forKey: "groupPrivateKey")
+            coder.encode(senderKeys, forKey: "senderKeys")
+            coder.encode(members, forKey: "members")
+            coder.encode(admins, forKey: "admins")
+        case .info(let groupPublicKey, let name, let senderKeys, let members, let admins):
+            coder.encode("info", forKey: "kind")
+            coder.encode(groupPublicKey, forKey: "groupPublicKey")
+            coder.encode(name, forKey: "name")
+            coder.encode(senderKeys, forKey: "senderKeys")
+            coder.encode(members, forKey: "members")
+            coder.encode(admins, forKey: "admins")
+        case .senderKeyRequest(let groupPublicKey):
+            coder.encode(groupPublicKey, forKey: "groupPublicKey")
+        case .senderKey(let groupPublicKey, let senderKey):
+            coder.encode("senderKey", forKey: "kind")
+            coder.encode(groupPublicKey, forKey: "groupPublicKey")
+            coder.encode([ senderKey ], forKey: "senderKeys")
+        }
+    }
+
+    // MARK: Proto Conversion
+    public override class func fromProto(_ proto: SNProtoContent) -> ClosedGroupUpdate? {
+        fatalError("Not implemented.")
+    }
+
+    public override func toProto() -> SNProtoContent? {
+        guard let kind = kind else {
+            SNLog("Couldn't construct closed group update proto from: \(self).")
+            return nil
+        }
+        do {
+            let closedGroupUpdate: SNProtoDataMessageClosedGroupUpdate.SNProtoDataMessageClosedGroupUpdateBuilder
+            switch kind {
+            case .new(let groupPublicKey, let name, let groupPrivateKey, let senderKeys, let members, let admins):
+                closedGroupUpdate = SNProtoDataMessageClosedGroupUpdate.builder(groupPublicKey: groupPublicKey, type: .new)
+                closedGroupUpdate.setName(name)
+                closedGroupUpdate.setGroupPrivateKey(groupPrivateKey)
+                closedGroupUpdate.setSenderKeys(try senderKeys.map { try $0.toProto() })
+                closedGroupUpdate.setMembers(members)
+                closedGroupUpdate.setAdmins(admins)
+            case .info(let groupPublicKey, let name, let senderKeys, let members, let admins):
+                closedGroupUpdate = SNProtoDataMessageClosedGroupUpdate.builder(groupPublicKey: groupPublicKey, type: .info)
+                closedGroupUpdate.setName(name)
+                closedGroupUpdate.setSenderKeys(try senderKeys.map { try $0.toProto() })
+                closedGroupUpdate.setMembers(members)
+                closedGroupUpdate.setAdmins(admins)
+            case .senderKeyRequest(let groupPublicKey):
+                closedGroupUpdate = SNProtoDataMessageClosedGroupUpdate.builder(groupPublicKey: groupPublicKey, type: .senderKeyRequest)
+            case .senderKey(let groupPublicKey, let senderKey):
+                closedGroupUpdate = SNProtoDataMessageClosedGroupUpdate.builder(groupPublicKey: groupPublicKey, type: .senderKey)
+                closedGroupUpdate.setSenderKeys([ try senderKey.toProto() ])
+            }
+            let contentProto = SNProtoContent.builder()
+            let dataMessage = SNProtoDataMessage.builder()
+            dataMessage.setClosedGroupUpdate(try closedGroupUpdate.build())
+            contentProto.setDataMessage(try dataMessage.build())
+            return try contentProto.build()
+        } catch {
+            SNLog("Couldn't construct closed group update proto from: \(self).")
+            return nil
+        }
+    }
 }
+
+private extension ClosedGroupSenderKey {
+
+    func toProto() throws -> SNProtoDataMessageClosedGroupUpdateSenderKey {
+        return try SNProtoDataMessageClosedGroupUpdateSenderKey.builder(chainKey: chainKey, keyIndex: UInt32(keyIndex), publicKey: publicKey).build()
+    }
+}
+