diff --git a/ts/session/messages/outgoing/OpenGroupMessage.ts b/ts/session/messages/outgoing/OpenGroupMessage.ts
index 286f9b593..c670a5e68 100644
--- a/ts/session/messages/outgoing/OpenGroupMessage.ts
+++ b/ts/session/messages/outgoing/OpenGroupMessage.ts
@@ -1,11 +1,6 @@
 import { Message, MessageParams } from './Message';
 import { AttachmentPointer, Preview, Quote } from './content';
-
-interface OpenGroup {
-  server: string;
-  channel: number;
-  conversationId: string;
-}
+import { OpenGroup } from '../../types/OpenGroup';
 
 interface OpenGroupMessageParams extends MessageParams {
   group: OpenGroup;
@@ -20,7 +15,7 @@ export class OpenGroupMessage extends Message {
   public readonly body?: string;
   public readonly attachments: Array<AttachmentPointer>;
   public readonly quote?: Quote;
-  public readonly preview: Array<Preview>;
+  public readonly preview?: Array<Preview>;
 
   constructor({
     timestamp,
diff --git a/ts/session/messages/outgoing/content/OpenGroupChatMessage.ts b/ts/session/messages/outgoing/content/OpenGroupChatMessage.ts
new file mode 100644
index 000000000..e69de29bb
diff --git a/ts/session/messages/outgoing/content/sync/OpenGroupSyncMessage.ts b/ts/session/messages/outgoing/content/sync/OpenGroupSyncMessage.ts
new file mode 100644
index 000000000..e69de29bb
diff --git a/ts/session/types/OpenGroup.ts b/ts/session/types/OpenGroup.ts
new file mode 100644
index 000000000..658f2f8d1
--- /dev/null
+++ b/ts/session/types/OpenGroup.ts
@@ -0,0 +1,82 @@
+// This is the Open Group equivalent to the PubKey type.
+
+interface OpenGroupParams {
+  server: string;
+  channel: number;
+  conversationId: string;
+}
+
+export class OpenGroup {
+  private static readonly serverRegex = new RegExp(
+    '^([\\w-]{2,}.){1,2}[\\w-]{2,}$'
+  );
+  private static readonly groupIdRegex = new RegExp(
+    '^publicChat:[0-9]*@([\\w-]{2,}.){1,2}[\\w-]{2,}$'
+  );
+  public readonly server: string;
+  public readonly channel: number;
+  public readonly groupId?: string;
+  public readonly conversationId: string;
+
+  constructor(params: OpenGroupParams) {
+    const strippedServer = params.server.replace('https://', '');
+    this.server = strippedServer;
+
+    // Validate server format
+    const isValid = OpenGroup.serverRegex.test(this.server);
+    if (!isValid) {
+      throw Error('an invalid server or groupId was provided');
+    }
+
+    this.channel = params.channel;
+    this.conversationId = params.conversationId;
+    this.groupId = OpenGroup.getGroupId(this.server, this.channel);
+  }
+
+  public static from(
+    groupId: string,
+    conversationId: string
+  ): OpenGroup | undefined {
+    // Returns a new instance from a groupId if it's valid
+    // eg. groupId = 'publicChat:1@chat.getsession.org'
+
+    const server = this.getServer(groupId);
+    const channel = this.getChannel(groupId);
+
+    // Was groupId successfully utilized?
+    if (!server || !channel) {
+      return;
+    }
+
+    const openGroupParams = {
+      server,
+      channel,
+      groupId,
+      conversationId,
+    } as OpenGroupParams;
+
+    if (this.serverRegex.test(server)) {
+      return new OpenGroup(openGroupParams);
+    }
+
+    return;
+  }
+
+  private static getServer(groupId: string): string | undefined {
+    const isValid = this.groupIdRegex.test(groupId);
+
+    return isValid ? groupId.split('@')[1] : undefined;
+  }
+
+  private static getChannel(groupId: string): number | undefined {
+    const isValid = this.groupIdRegex.test(groupId);
+    const channelMatch = groupId.match(/^.*\:([0-9]*)\@.*$/);
+
+    return channelMatch && isValid ? Number(channelMatch[1]) : undefined;
+  }
+
+  private static getGroupId(server: string, channel: number): string {
+    // server is already validated in constructor; no need to re-check
+    return `publicChat:${channel}@${server}`;
+  }
+}
diff --git a/ts/test/session/messages/OpenGroupMessage_test.ts b/ts/test/session/messages/OpenGroupMessage_test.ts
index 7223ca394..ad05c5b6e 100644
--- a/ts/test/session/messages/OpenGroupMessage_test.ts
+++ b/ts/test/session/messages/OpenGroupMessage_test.ts
@@ -5,13 +5,14 @@ import {
   OpenGroupMessage,
 } from '../../../session/messages/outgoing';
 import * as MIME from '../../../../ts/types/MIME';
+import { OpenGroup } from '../../../session/types/OpenGroup'
 
 describe('OpenGroupMessage', () => {
-  const group = {
-    server: 'server',
+  const group = new OpenGroup({
+    server: 'chat.example.server',
     channel: 1,
     conversationId: '0',
-  };
+  });
 
   it('can create empty message with just a timestamp and group', () => {
     const message = new OpenGroupMessage({