ModernUO/dev-docs/configuration.md

ModernUO Configuration System

This document covers ModernUO's configuration system, including ServerConfiguration for global settings, JsonConfig for custom config files, and best practices.

Overview

ModernUO has two configuration mechanisms:

1. ServerConfiguration: Global key-value settings stored in modernuo.json
2. JsonConfig: Custom JSON configuration files for complex data structures

ServerConfiguration

Defined in Projects/Server/Configuration/ServerConfiguration.cs.

Reading Settings

GetSetting (Read-Only)

Returns the configured value or the default. Does NOT write the default to the config file.

int statMax = ServerConfiguration.GetSetting("stats.statMax", 100);
bool enabled = ServerConfiguration.GetSetting("mySystem.enabled", true);
TimeSpan delay = ServerConfiguration.GetSetting("autosave.saveDelay", TimeSpan.FromMinutes(5));
double rate = ServerConfiguration.GetSetting("stats.gainChanceMultiplier", 1.0);
Expansion exp = ServerConfiguration.GetSetting("core.expansion", Expansion.ML);

Supported types:

• int
• bool
• double
• TimeSpan
• T where T : struct, Enum

GetOrUpdateSetting (Read-Write)

Returns the configured value. If the key doesn't exist, writes the default to the config file and returns it.

int maxAccounts = ServerConfiguration.GetOrUpdateSetting("accountHandler.maxAccountsPerIP", 1);
bool autoCreate = ServerConfiguration.GetOrUpdateSetting("accountHandler.enableAutoAccountCreation", true);
int poolSize = ServerConfiguration.GetOrUpdateSetting("timer.initialPoolCapacity", 1024);

Use this when you want new settings to appear in modernuo.json automatically with sensible defaults.

SetSetting

Directly sets a value and immediately persists to disk:

ServerConfiguration.SetSetting("mySystem.enabled", "true");
ServerConfiguration.SetSetting("mySystem.maxItems", "100");

Configuration Pattern

Read settings in your Configure() static method:

namespace Server.Custom;

public static class MySystem
{
    private static bool _enabled;
    private static int _maxItems;
    private static TimeSpan _cooldown;

    public static void Configure()
    {
        _enabled = ServerConfiguration.GetOrUpdateSetting("mySystem.enabled", true);
        _maxItems = ServerConfiguration.GetOrUpdateSetting("mySystem.maxItems", 100);
        _cooldown = ServerConfiguration.GetOrUpdateSetting("mySystem.cooldown", TimeSpan.FromMinutes(5));
    }

    public static void Initialize()
    {
        if (!_enabled)
            return;

        // System initialization that depends on config values
    }
}

Key Naming Convention

Use dot-separated hierarchical keys:

systemName.settingName
systemName.subSystem.settingName

Examples from the codebase:

accountHandler.enableAutoAccountCreation
accountHandler.enablePlayerPasswordCommand
accountHandler.maxAccountsPerIP
accountSecurity.encryptionAlgorithm
autosave.enabled
autosave.saveDelay
world.savePath
world.useMultithreadedSaves
movement.delay.walkFoot
movement.delay.runFoot
stats.statMax
stats.gainChanceMultiplier
stats.primaryStatGainChance
stats.gainDelay
stats.petGainDelay
stats.usePub45StatGain
timer.initialPoolCapacity
timer.maxPoolCapacity
core.enableIdleCPU

modernuo.json Structure

Located at Distribution/Configuration/modernuo.json:

{
  "assemblyDirectories": ["./Assemblies"],
  "dataDirectories": ["C:\\Ultima Online Classic"],
  "listeners": ["0.0.0.0:2593"],
  "settings": {
    "accountHandler.enableAutoAccountCreation": "True",
    "accountHandler.maxAccountsPerIP": "1",
    "autosave.enabled": "True",
    "autosave.saveDelay": "00:05:00",
    "world.savePath": "Saves",
    "stats.statMax": "100"
  }
}

Key points:

• All settings are stored as strings in the settings dictionary
• Top-level fields (assemblyDirectories, dataDirectories, listeners) are structural
• GetOrUpdateSetting adds new entries to settings automatically

---

JsonConfig

For complex configuration that doesn't fit in flat key-value pairs, use JsonConfig.

Defined in Projects/Server/Json/JsonConfig.cs.

API

// Deserialize from file (returns default if file doesn't exist)
T config = JsonConfig.Deserialize<T>(filePath);
T config = JsonConfig.Deserialize<T>(filePath, customOptions);

// Serialize to file (creates directory if needed)
JsonConfig.Serialize(filePath, config);
JsonConfig.Serialize(filePath, config, customOptions);

// Default options (available for customization)
JsonSerializerOptions options = JsonConfig.DefaultOptions;

Default JSON Options

WriteIndented = true                           // Pretty-printed
AllowTrailingCommas = true                     // Forgiving parser
ReadCommentHandling = JsonCommentHandling.Skip // Comments allowed
DefaultIgnoreCondition = WhenWritingNull       // Null values omitted
Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping

Built-in Converters

JsonConfig includes converters for ModernUO types:

• ClientVersion
• Guid
• Map
• Point3D
• Rectangle3D
• TimeSpan
• IPEndPoint
• Type
• WorldLocation
• TextDefinition
• All enums (as strings via JsonStringEnumConverter)

Custom Config File Pattern

using Server.Json;

namespace Server.Custom;

public class MySystemConfig
{
    public bool Enabled { get; set; } = true;
    public int MaxItems { get; set; } = 100;
    public TimeSpan Cooldown { get; set; } = TimeSpan.FromMinutes(5);
    public List<string> BlockedNames { get; set; } = new();
    public Dictionary<string, int> Scores { get; set; } = new();
}

public static class MySystem
{
    private static MySystemConfig _config;
    private static readonly string ConfigPath =
        Path.Combine(Core.BaseDirectory, "Configuration/MySystem/config.json");

    public static void Configure()
    {
        _config = JsonConfig.Deserialize<MySystemConfig>(ConfigPath);

        if (_config == null)
        {
            _config = new MySystemConfig();
            JsonConfig.Serialize(ConfigPath, _config);
        }
    }

    public static void SaveConfig()
    {
        JsonConfig.Serialize(ConfigPath, _config);
    }
}

This creates a config file like:

{
  "Enabled": true,
  "MaxItems": 100,
  "Cooldown": "00:05:00",
  "BlockedNames": [],
  "Scores": {}
}

Custom Converters

Add custom converters via JsonConfig.GetOptions():

var options = JsonConfig.GetOptions(new MyCustomConverterFactory());
var data = JsonConfig.Deserialize<MyType>(path, options);

---

Configuration File Locations

File	Purpose
Distribution/Configuration/modernuo.json	Main server settings
Distribution/Configuration/expansion.json	Target expansion
Distribution/Data/expansions.json	Expansion metadata
Distribution/Configuration/	Custom config directory

Custom config files should be placed under Distribution/Configuration/ in a subdirectory named after your system.

Best Practices

1. Read in Configure() -- called before Initialize(), ensures settings are available early
2. Use GetOrUpdateSetting for new features -- ensures defaults appear in config file
3. Use GetSetting for optional/advanced settings -- doesn't clutter config file
4. Use JsonConfig for complex data -- lists, dictionaries, nested objects
5. Provide sensible defaults -- system should work without manual configuration
6. Use era-aware defaults -- Core.LBR ? 125 : 100 for values that vary by expansion
7. Document key names -- use clear hierarchical naming

Key File References

File	Description
Projects/Server/Configuration/ServerConfiguration.cs	ServerConfiguration class
Projects/Server/Json/JsonConfig.cs	JsonConfig utility
Distribution/Configuration/modernuo.json	Main config file
Projects/UOContent/Skills/SkillCheck.cs	Config usage example
Projects/Server/Timer/Timer.Pool.cs	Config usage example