Matrix / Element communication platform

Introduction

Matrix is an open, secure, and decentralized communication platform designed for modern collaboration. It enables you to:

• Chat with individuals or groups
• Join public or private rooms
• Share files, images, and links
• Communicate securely using end-to-end encryption (E2EE)

This guide walks you through using Element, the official Matrix client, provisioned on-premise on the e-INFRA CZ infrastructure.

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Accessing Matrix

Prerequisites

To use Matrix, you must have an active MetaCentrum account.

How to Get Access

The CERIT-SC AI services are integrated with the national research infrastructure MetaCentrum. If you don’t have an account yet, apply through the:

👉 MetaCentrum registration form

Once your MetaCentrum account is active, access the platform directly

👉 https://element.cloud.e-infra.cz/

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Logging In

Open your web browser and navigate to

👉 https://element.cloud.e-infra.cz/

Select your preferred authentication method:

• Option A – via Home Organization:

  • Select your home institution.
  • Log in using your institutional credentials (eduID.cz).

• Option B – via e-INFRA CZ Password:

  • Select e-INFRA CZ password.
  • Enter your MetaCentrum username and password.

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Import Your Account

After authenticating, Matrix may prompt you to import settings or restore an existing session.

• First-time users: Proceed with the standard setup.
• Existing users: Follow the on-screen instructions to import your encrypted data from an active session or backup key.

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Welcome Screen & Initial Setup

When signing in for the first time, you will see the welcome screen and be guided through two initial setup tasks before accessing your messages:

1. Encryption setup
2. Notification settings

Setting Up Encryption

Matrix uses End-to-End Encryption (E2EE) to secure your messages.

• Only conversation participants can read messages.
• Server administrators cannot inspect your encrypted communication.
• Your chats remain completely private.

To start configuring key backup, click Continue.

Get Your Recovery Key

Matrix will generate a unique Recovery Key.

This key is essential to:

• Restore encrypted message history.
• Verify new devices.
• Recover access if you log out on all sessions.

Save Your Recovery Key

Store your key in a safe, persistent location. Recommended options:

• A secure password manager
• An encrypted file store
• A printed physical copy stored securely

Verify via Recovery Key

When signing in on a new device, Matrix will ask for this key to unlock your historical chats.

• Enter or paste your Recovery Key.
• Click Finish set up.

Once entered, your encrypted conversations will be decrypted and available on the new device.

Notifications Setup

Element will request permission to send browser notifications.

Enable notifications to receive real-time alerts for:

• Direct messages
• @mentions
• Room invitations
• New activity in active rooms

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Main Interface (Home Page)

Once setup is complete, you will land on the primary Matrix workspace.

The main interface includes:

• Rooms – Group chat rooms you have joined.
• People – One-on-one direct messages.
• Spaces – Collections or folders organizing related rooms.
• Search – Global search for people, rooms, and message history.
• Settings – Personal preferences, security, and profile configuration.

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Finding & Messaging People

Search for People

1. Click the Search field in the top bar or sidebar.
2. Enter the person’s name or Matrix ID.
3. Select the user from the results list.

Start a Conversation

1. Search for the user and select their profile.
2. Click Message or Start Chat.
3. Send your initial message.

Once started, you can share messages, files, code snippets, links, and images securely.

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Joining Public Rooms

Matrix hosts central public channels. Two main rooms are available for discussion regarding the infrastructure’s LLM services:

1. LLM - Status (System updates, releases, and outages)
2. LLM - General (Open discussion on LLM topics and usage)

How to Find and Join Public Rooms:

1. Click Explore Rooms (Room Directory).
2. Enter a keyword (e.g., LLM) into the search bar.
3. Browse the room directory list.
4. Click View to preview a room.

5. Click Join the discussion to become a member.

Joined rooms will now remain saved on your sidebar home interface for quick access.

Inviting Members to a Room

If you have permission to invite members to a specific room:

1. Open the designated room.
2. Open the Room Information panel (top right).
3. Select Members.
4. Click Invite.
5. Search for the user (must be a registered Matrix user).
6. Send the invitation.

The invited user will receive an in-app notification to accept or decline the room invitation.

Mobile Setup: Element X App

Access your e-INFRA CZ Matrix account on mobile (iOS/Android) using Element X, the modern and lightweight Matrix client.

Install the App

Download Element X from your official store:

• iOS: App Store — Search for Element X
• Android: Google Play — Search for Element X

Change the Server (Important)

By default, Element X connects to public matrix.org. Point the client to the local e-INFRA CZ server:

1. On the welcome screen, tap Change Server (or ** Choose Server**).
2. Enter the custom server URL: matrix.cloud.e-infra.cz
3. Tap Continue or Confirm.

Login

Authenticate through your mobile browser using your eduID.cz or e-INFRA CZ password credentials.

Verify Your Mobile Device

To read encrypted history on your phone, verify your session using one of the following methods:

• Option A (Use another device): Compare the sequence of emojis displayed on both your computer screen and mobile device. If they match, tap Confirm on both devices.

• Option B (Recovery Key): If you don’t have an active web session open on another device, select Use Recovery Key and enter your saved key.

Configure Notifications

To receive push notifications on your mobile device for incoming messages:

1. When prompted after login, grant the app permission to send system notifications. Make sure notification permissions are also allowed in your mobile operating system settings.

2. Or later, open the app settings (tap your profile icon in the top left corner).
3. Go to Notifications.
4. Configure your alert levels:
   • All Messages: Receive notifications for every message in joined rooms.
   • Mentions & Keywords Only: Receive notifications only when your username is mentioned or tagged.

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Quick Security & Best Practices Summary

• Safeguard your recovery key: Keep it stored safely in a password manager. Loss of this key means losing historical encrypted messages.
• Configure notifications: Ensure device notifications are active so you don’t miss important user mentions or room invites.
• Use direct messages vs. rooms: Use DMs for private 1-on-1 chats and Rooms for group projects and topic discussion.
• Verify devices: Always verify newly logged-in mobile or browser sessions to ensure continuous end-to-end encryption integrity.