diff --git a/ts/session/types/ClosedGroup.ts b/ts/session/types/ClosedGroup.ts
new file mode 100644
index 000000000..0eddf992b
--- /dev/null
+++ b/ts/session/types/ClosedGroup.ts
@@ -0,0 +1,134 @@
+
+
+// This is the (Closed | Medium) Group equivalent to the SessionGroup type.
+
+import { PubKey } from '.';
+import { UserUtil } from '../../util';
+
+enum ClosedGroupType {
+    SMALL,
+    MEDIUM,
+}
+
+interface ClosedGroupParams {
+    id: PubKey;
+    type: ClosedGroupType;
+    admins: Array<PubKey>;
+    members: Array<PubKey>;
+}
+
+class ClosedGroup {
+  public readonly id: PubKey;
+  public readonly type: ClosedGroupType;
+  public admins: Array<PubKey>;
+  public members: Array<PubKey>;
+
+  constructor(params: ClosedGroupParams) {
+    this.id = params.id;
+    this.type = params.type;
+    this.admins = params.admins;
+    this.members = params.members;
+  }
+
+  public static async create(name: string, type: ClosedGroupType, members: Array<PubKey>, onSuccess: any): Promise<ClosedGroup | undefined> {
+    const { ConversationController, StringView, libsignal } = window;
+
+    // Manage small group size
+    // TODO - Eventually we want to default to MediumGroups and abandon regular groups
+    // once medium groups have been thoroughly tested
+    if (
+      type === ClosedGroupType.SMALL &&
+      members.length === 0 ||
+      members.length >= window.CONSTANTS.SMALL_GROUP_SIZE_LIMIT
+    ) {
+      console.warn(`ClosedGroup create: Cannot create a small group with more than ${window.CONSTANTS.SMALL_GROUP_SIZE_LIMIT} members`);
+    }
+
+    const primaryDevice = UserUtil.getCurrentPrimaryDevicePubKey();
+    const allMembers = [primaryDevice, ...members];
+
+    // Create Group Identity
+    const identityKeys = await libsignal.KeyHelper.generateIdentityKeyPair();
+
+    const keypair = await libsignal.KeyHelper.generateIdentityKeyPair();
+    const id = StringView.arrayBufferToHex(keypair.pubKey);
+
+    // Medium groups
+    const senderKey = (type === ClosedGroupType.MEDIUM)
+        ? await window.SenderKeyAPI.createSenderKeyForGroup(id, primaryDevice)
+        : undefined;
+
+    const secretKey = (type === ClosedGroupType.MEDIUM)
+        ? identityKeys.privKey
+        : undefined;
+
+    const groupSecretKeyHex = StringView.arrayBufferToHex(
+    identityKeys.privKey
+    );
+
+    const ev = {
+    groupDetails: {
+        id,
+        name,
+        members: allMembers,
+        recipients: allMembers,
+        active: true,
+        expireTimer: 0,
+        avatar: '',
+        secretKey,
+        senderKey,
+        is_medium_group: type === ClosedGroupType.MEDIUM,
+    },
+    confirm: () => null,
+    };
+
+    await window.NewReceiver.onGroupReceived(ev);
+    }
+
+    public static get(id: PubKey): ClosedGroup | undefined {
+        // Gets a closed group from its group id
+        return;
+    }
+
+    public update(): Promise<Array<PubKey>> {
+        // 
+    }
+
+    public updateMembers(): Promise<Array<PubKey>> {
+        // Abstraction on update
+
+        // Update the conversation and this object
+    }
+
+    public async removeMembers(): Promise<Array<PubKey>> {
+        // Abstraction on updateMembers
+    }
+
+    public async addMembers(): Promise<Array<PubKey>> {
+        // Abstraction on updateMembers
+    }
+
+    public async setName(): Promise<void> {
+        // Set or update the name of the group
+    }
+
+    public leave() {
+        // Leave group
+    }
+
+
+    //   static from(groupId) {
+    //       // Returns a new instance from a groupId if it's valid
+    //       const groupIdAsPubKey = groupId instanceof _1.PubKey
+    //           ? groupId
+    //           : _1.PubKey.from(groupId);
+    //       openGroupParams = {
+    //           groupId: 
+    //       };
+    //       return new SessionGroup(openGroupParams);
+    //   }
+
+
+}
+
+
diff --git a/ts/test/session/sending/MessageSender_test.ts b/ts/test/session/sending/MessageSender_test.ts
index 1a6e33ee0..ccc729c29 100644
--- a/ts/test/session/sending/MessageSender_test.ts
+++ b/ts/test/session/sending/MessageSender_test.ts
@@ -49,6 +49,7 @@ describe('MessageSender', () => {
         [string, Uint8Array, number, number],
         Promise<void>
       >();
+       
       TestUtils.stubWindow('lokiMessageAPI', {
         sendMessage: lokiMessageAPISendStub,
       });
diff --git a/ts/util/user.ts b/ts/util/user.ts
index cea991b17..bacaefb69 100644
--- a/ts/util/user.ts
+++ b/ts/util/user.ts
@@ -10,6 +10,15 @@ export async function getCurrentDevicePubKey(): Promise<string | undefined> {
   return item.value.split('.')[0];
 }
 
+export async function getCurrentPrimaryDevicePubKey(): Promise<string | undefined> {
+  const item = await getItemById('primaryDevicePubKey');
+  if (!item || !item.value) {
+    return undefined;
+  }
+
+  return item.value;
+}
+
 export async function getIdentityKeyPair(): Promise<KeyPair | undefined> {
   const item = await getItemById('identityKey');