Quassel IRC

Modern distributed IRC client with persistent connections

Quassel IRC

Quassel IRC is a modern, cross-platform, distributed IRC client based on the Qt framework. Unlike traditional IRC clients, Quassel uses a unique client-server architecture where the core (server) stays connected to IRC networks 24/7, while multiple clients can connect and disconnect at will without losing your IRC connection.

What is Quassel IRC?

Quassel IRC is a distributed IRC client that separates the core functionality from the user interface. The Quassel Core runs continuously on your QuickBox server, maintaining persistent IRC connections, while Quassel Client applications can connect from any device to access your IRC sessions.

Installation

Prerequisites

Before installing Quassel Core, ensure your environment meets these requirements:

Install Quassel Core

Install Quassel IRC core for a specific user:

qb install quassel -u username

Automatic Installation Process

QuickBox handles complete Quassel Core setup:

1. 📦 Package Installation - Installs quassel-core from system repositories
2. 🔐 SSL Certificate Generation - Creates secure certificates for client connections
3. ⚙️ Service Configuration - Sets up systemd service with user-specific settings
4. 📁 Directory Structure - Creates config directories and sets proper permissions
5. 🔒 Security Hardening - Configures firewall rules and access controls
6. 🗄️ Database Integration - Registers service in QuickBox database
7. 🚀 Service Activation - Enables and starts Quassel Core service
8. 💾 Automatic Backup - Creates initial configuration backup

CLI Commands

Basic Operations

Usage Examples

Install Quassel Core:

qb install quassel -u myuser

Update Quassel Core:

qb update quassel -u myuser

Reinstall (fix corrupted installation while preserving data):

qb reinstall quassel -u myuser

Remove Quassel Core:

qb remove quassel -u myuser

Configuration

Default Settings

Quassel Core is configured with the following defaults:

Environment Configuration

Quassel Core uses environment variables defined in /etc/default/quasselcore:

# Log Level: Debug|Info|Warning|Error
LOGLEVEL="Info"
 
# Log file location
LOGFILE="/home/username/.config/Quassel/logs/core.log"
 
# Port for client connections (default: 4242)
PORT="4242"
 
# Network addresses to listen on (IPv6 and IPv4)
LISTEN="::,0.0.0.0"
 
# Data directory
DATADIR="/var/lib/quassel"

Port Configuration

By default, Quassel Core listens on port 4242. QuickBox automatically handles:

• Port availability checking
• Automatic port assignment if default is in use
• Firewall rule configuration
• Database port registration

Check your assigned port:

cat /etc/default/quasselcore | grep PORT

Allow port through UFW firewall:

# Allow from specific IP
ufw allow from 203.0.113.50 to any port 4242
 
# Allow from anywhere (not recommended)
ufw allow 4242/tcp

Advanced Configuration

Customize log level:

# Edit environment file
nano /etc/default/quasselcore
 
# Change LOGLEVEL (Debug|Info|Warning|Error)
LOGLEVEL="Debug"
 
# Restart service
systemctl restart quasselcore

Change listening addresses:

# Edit environment file
nano /etc/default/quasselcore
 
# Listen only on IPv4
LISTEN="0.0.0.0"
 
# Listen only on IPv6
LISTEN="::"
 
# Listen on both (default)
LISTEN="::,0.0.0.0"
 
# Restart service
systemctl restart quasselcore

Connecting to Quassel Core

Accessing Your Quassel Core

After installation, you’ll need the Quassel Client application to connect to your core. Unlike web-based IRC clients, Quassel requires a desktop or mobile application.

Download Quassel Client

Desktop Clients:

Mobile Clients:

First-Time Connection Setup

Step 1: Launch Quassel Client

Open the Quassel Client application on your device.

Step 2: Add Core Account

1. Click “Add Core Account” or navigate to connection settings
2. Enter your connection details:

Core Account Name: My QuickBox Server
Hostname:          your-server.com (or IP address)
Port:              4242

3. Enable “Use Secure Connection (SSL)” ✓

Step 3: Accept SSL Certificate

To verify certificate fingerprint on your server:

openssl x509 -in ~/.ssl/quasselCert.pem -noout -fingerprint -sha256

Step 4: Create User Account

Since this is your first connection, you’ll create the initial admin account:

1. Click “Add User”
2. Enter username and strong password
3. This becomes your Quassel Core account (separate from IRC networks)

Step 5: Add IRC Networks

Configure IRC networks you want to connect to:

1. Right-click on your identity → “Configure Networks”

2. Click “Add” to create a new network

3. Common IRC networks:

   • Libera.Chat: irc.libera.chat:6697 (SSL)
   • OFTC: irc.oftc.net:6697 (SSL)
   • IRCnet: irc.ircnet.com:6667

4. Configure authentication (if required by network)

5. Set auto-join channels

Connection Settings Reference

Required Connection Parameters:

Find your assigned port:

cat /etc/default/quasselcore | grep "^PORT="

Multiple Client Connections

One of Quassel’s key features is multi-client support:

• Connect from desktop, laptop, tablet, and phone simultaneously
• All clients share the same conversation state
• Read/unread status syncs across all devices
• Disconnect any client without losing IRC connection

Example use case:

1. Connect from desktop at work
2. Disconnect and connect from phone during commute
3. Resume from laptop at home
4. All conversations and history available everywhere

Service Management

Quassel Core runs as a systemd service for reliable operation:

Basic Service Commands

Check service status:

systemctl status quasselcore

Start service:

systemctl start quasselcore

Stop service:

systemctl stop quasselcore

Restart service:

systemctl restart quasselcore

Enable service (start on boot):

systemctl enable quasselcore

Disable service:

systemctl disable quasselcore

Viewing Logs

View service logs:

journalctl -u quasselcore -f

View core log file:

tail -f /home/username/.config/Quassel/logs/core.log

Check last 100 log entries:

journalctl -u quasselcore -n 100

Features

Core Features

Client Features

When connected via Quassel Client:

• Cross-Platform: Windows, macOS, Linux, and mobile clients
• Synchronized State: All clients share the same read/unread status
• Rich Interface: Context menus, keyboard shortcuts, and customizable layouts
• Advanced Search: Full-text search across conversation history
• Identity Management: Multiple nicknames and authentication methods
• File Transfers: DCC send/receive with resume support

Directory Structure

Quassel stores configuration and data in user-specific directories:

Troubleshooting

Common Issues & Solutions

Service Won’t Start

Symptoms: systemctl start quasselcore fails or service immediately stops

Solutions:

1. Check service status: systemctl status quasselcore
2. Review logs: journalctl -u quasselcore -n 50
3. Verify permissions: ls -la /home/username/.config/Quassel/
4. Check port availability: ss -tlnp | grep 4242
5. Reinstall if corrupted: qb reinstall quassel -u username

Client Connection Refused

Symptoms: Quassel client cannot connect to core, timeout errors

Solutions:

1. Verify service is running: systemctl is-active quasselcore
2. Check port is listening: netstat -tlnp | grep 4242
3. Test local connection: telnet localhost 4242
4. Verify firewall rules: ufw status or iptables -L
5. Check client SSL settings match server configuration

SSL Certificate Errors

Symptoms: Certificate verification failed, untrusted certificate warnings

Solutions:

1. Verify certificate exists: ls -la ~/.ssl/quasselCert.pem
2. Check certificate validity: openssl x509 -in ~/.ssl/quasselCert.pem -noout -dates
3. Regenerate certificate: qb reinstall quassel -u username
4. Accept certificate in client (verify fingerprint first)

Database Corruption

Symptoms: Core crashes on startup, SQLite errors in logs

Solutions:

1. Stop service: systemctl stop quasselcore
2. Backup current database: cp ~/.config/Quassel/quassel-storage.sqlite ~/quassel-backup.sqlite
3. Restore from backup: cp ~/.local/share/quickbox/backups/quassel/backup/quassel-storage.sqlite ~/.config/Quassel/
4. Fix permissions: chown username:username ~/.config/Quassel/*.sqlite
5. Start service: systemctl start quasselcore

Service Health Checks

Verify core is running:

systemctl is-active quasselcore

Check port listening:

ss -tlnp | grep 4242

Test local connection:

telnet localhost 4242

Verify SSL certificate:

openssl x509 -in ~/.ssl/quasselCert.pem -text -noout

Best Practices

Security Recommendations

• Use strong passwords for Quassel user accounts
• Enable SSL/TLS for all client connections
• Restrict port access via firewall to known IPs
• Regular updates to address security vulnerabilities
• Monitor connections via logs and systemd status

When to Use Quassel

Additional Resources

Related Applications

Quassel IRC works well alongside these QuickBox Pro communication tools:

QuickBox Integration

Quassel Core integrates seamlessly with QuickBox Pro:

• Dashboard Widget: Monitor Quassel Core status from QuickBox dashboard
• User Management: Per-user installations with isolated configurations
• Automatic Backups: Configuration and database backed up during updates
• Service Monitoring: Health checks and automatic restart on failure
• Database Tracking: Version and port information stored in QuickBox database
• SSL Integration: Shared SSL infrastructure with other QuickBox services

Support & Community

Need help with Quassel IRC? The QuickBox community is here to help!

Getting Help