Send group messages with the Logos Chat app

Create a three-member end-to-end encrypted group conversation in the Logos Chat app, invite members by address, and send a message that reaches all of them.

Version

This document is accurate for Testnet v0.3.0.

This procedure shows how to use the Logos Chat app to form an end-to-end encrypted group conversation between three running instances, here called Alice, Bob, and Carol. Group conversations use de-MLS encryption from the logos-chat-module, and Logos Delivery carries the encrypted messages between instances. Use this procedure to try group creation, invite-by-address, asynchronous membership changes, and messages that reach every member with their sender named.

Each launch of the app starts a new identity with a new address. Conversations from an earlier launch stay readable under Previous sessions but can't be sent to, and a group comes back only once a member invites your new address. A group's name and description are fixed when it is created, and in this release membership only grows: members can't be removed and can't leave.

Prerequisites

• A supported OS:
  • Linux
  • macOS
• Network access, so that the three instances can reach the logos.test network and the key-package registry
• Basecamp installed.
• RLN membership registered.

What to expect

• You can send a message to a group conversation and see it arrive in every member's window with the sender's name and avatar.
• You can create a named group and invite members by pasting their addresses.
• You can watch an invited member move from Waiting to join to a full member as the group commits the change.

Step 1: Run three instances of the Logos Chat app

One Basecamp instance is one chat identity, so use this option when the three participants are on separate machines.

1. In the left bar, select Package Manager.
2. Find Chat in the package list and click INSTALL in its row. Click Install in the Install Package? dialogue to confirm, along with the chat_module and delivery_module packages it depends on.
3. Wait until the Action column reads INSTALLED for both Chat and Chat Module.
4. In the left bar, select the chat icon to launch the Logos Chat app.

Step 2: Collect Bob's and Carol's addresses

In Bob's and Carol's windows:

1. Wait until the account card shows Online.
2. Click the copy button next to the address on the account card (Copy my address).
3. Send the address to Alice through any out-of-band communication channel.

Step 3: Create the group

In Alice's window:

1. Click New chat at the top of the conversations card, then select Group ("Named, with members").

2. Fill in Group name, for example Book Club, and optionally Description (optional), for example Weekly sci-fi picks. Neither can be changed after creation.

3. Click Create.

   Expected result: the group opens as the current conversation, with Alice as its only member. A right-hand column appears with the Members roster and Add member at its foot.

   

Step 4: Invite Bob

Membership changes are asynchronous. The group's steward batches an add into an MLS commit after a commit-inactivity window of about 60 seconds, and the welcome goes out only after the commit lands, so a new member joins minutes after the invite. Wait for Bob to join before inviting Carol, so that the second add starts from a settled group.

In Alice's window:

1. In the Members card, click Add member.

2. Paste Bob's address, then click Add.

3. An explainer appears: "Adding a member isn't instant. Membership updates apply on a timer, so a new member can take up to a minute to appear." Click Add member to confirm.

   

   • Select Don't show this again to skip the explainer next time.

   Expected result: Bob appears on Alice's roster as a dimmed row reading Waiting to join. Some minutes later, the group appears in Bob's conversation list with the name Alice gave it, and his row on the roster stops being dimmed.

Step 5: Invite Carol

1. In Alice's window, repeat Step 4 with Carol's address.

   • Any member can add another; the invite routes from whoever proposed it.

   

2. Wait until the group appears in Carol's conversation list.

   Expected result: all three rosters converge on three members, none of them dimmed or reading Waiting to join. The conversation's Details panel, opened with the toggle in the thread header, shows 3 joined.

   

Step 6: Send a message to the group

1. In Alice's window, select the group, type a message in the composer, and press Enter or click the send arrow.

   Expected result: the message appears right-aligned in Alice's thread. Within a few seconds to about two minutes, it appears in Bob's and Carol's threads as an incoming, left-aligned message with Alice's avatar and name above it. Sender attribution is what distinguishes a group thread from a direct message.

2. In Bob's window, reply to the group.

   Expected result: Bob's reply reaches both Alice and Carol.

   

Troubleshooting Logos Chat groups

An invited member stays on the roster as "Waiting to join" for minutes

This is by design, not a hang. The add is a consensus proposal that the group's steward batches into an MLS commit after a commit-inactivity window of about 60 seconds, and the welcome only goes out after the commit lands. Wait, and invite one member at a time, letting each join land before the next invite.

A send fails right after a membership change

de-MLS rejects sends during the brief window while the group finalises the epoch change. The failure shows on the status bar at the foot of the window. Retry after a few seconds.

The account card never reaches Online, or the conversations pane shows "Waiting for connection…"

The instance has no route to the logos.test fleet or to the key-package registry, for example because it is offline, sandboxed, or has its peer-to-peer ports blocked. Run it with real network access. The session logs, under Logs or Full logs in the app, say which module failed and where its log file is.

Two instances on one host interfere with each other

They were given the same session directory. Give each instance its own --user-dir.