What is MDT (FiveM): In-Game Police Computer Systems

MDT systems in FiveM are interactive interfaces that simulate law enforcement computer terminals, enabling players to access criminal databases, file reports, and manage emergency service operations within roleplay servers.

Technical Architecture

MDTs typically use one of three implementation approaches:

1. NUI (CEF) Based – Most Common

-- Client-side NUI trigger example
RegisterCommand('mdt', function()
    SetNuiFocus(true, true)
    SendNUIMessage({
        type = 'open',
        officer = GetPlayerName(PlayerId()),
        badge = GetPlayerServerId(PlayerId())
    })
end)

-- Server-side database query
RegisterServerEvent('mdt:searchPerson')
AddEventHandler('mdt:searchPerson', function(firstname, lastname)
    MySQL.Async.fetchAll('SELECT * FROM users WHERE firstname = @first AND lastname = @last', {
        ['@first'] = firstname,
        ['@last'] = lastname
    }, function(result)
        TriggerClientEvent('mdt:returnSearch', source, result)
    end)
end)

2. External Web Application

• Standalone web app (React/Vue.js)
• Communicates via REST API or WebSockets
• Example endpoint structure:

// API endpoint example
app.post('/api/mdt/warrant/create', authenticate, (req, res) => {
    const { suspect_id, charges, issuing_officer } = req.body;
    // Database insertion logic
});

3. In-Game Tablet Resource

• Uses FiveM’s tablet prop with custom UI
• More immersive but performance-intensive

Core Features Implementation

Database Schema Example:

CREATE TABLE mdt_reports (
    id INT AUTO_INCREMENT PRIMARY KEY,
    incident_id VARCHAR(10) UNIQUE,
    reporting_officer INT,
    suspects TEXT,
    charges TEXT,
    evidence TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE mdt_warrants (
    id INT AUTO_INCREMENT PRIMARY KEY,
    citizen_id INT,
    charges TEXT,
    status ENUM('active', 'served', 'expired'),
    issued_by INT,
    issued_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

Popular MDT Resources

1. ox_mdt – Lightweight, ESX/QBCore compatible
2. ps-mdt – Feature-rich with evidence system
3. sonoran_mdt – CAD integration, subscription-based

Integration Requirements

Framework Dependencies:

• ESX: Requires es_extended, mysql-async/oxmysql
• QBCore: Requires qb-core, qb-policejob

Permission System:

-- Job-based access control
if PlayerData.job.name == 'police' and PlayerData.job.grade >= 2 then
    -- Allow MDT access
end

Performance Considerations

• Cache frequently accessed data (warrants, BOLOs)
• Implement pagination for large datasets
• Limit real-time updates to essential features
• Average resource usage: 0.05-0.20ms (idle), 0.50-2.00ms (active)

Common Implementation Issues

1. Database Connection Pooling – Ensure proper connection limits
2. Image Storage – Use external CDN for mugshots/evidence photos
3. Real-time Sync – WebSocket connections can overload weak servers

MDT systems transform FiveM roleplay servers by providing realistic law enforcement tools through NUI interfaces that connect to server databases for managing criminal records, reports, and emergency service operations.