Persistence

Everything you store in script fields (_rewardGiven, _gangMembers) vanishes into thin air when you close GTA V or press the reload key. If you want a gang reputation score, bought property, or custom vehicle garage to survive between play sessions, you must write that state to disk.

The great news: there is no GTA native for saving data. You use standard, battle-tested C# and .NET: System.IO and System.Text.Json.

The data contract: Keep it pure

Define a dedicated class or struct to represent your saved state:

public sealed class PlayerProfile
{
    public const int CurrentVersion = 1;

    public int Version { get; set; } = CurrentVersion;
    public int Reputation { get; set; }
    public int MissionsCompleted { get; set; }
}

Notice the Version property. When you update your mod next month and add five new fields, checking Version == CurrentVersion tells you whether the file on disk is compatible or needs migration.

Writing JSON to disk

Saving is a two-step process: serialize the object to a JSON string, then write it to a file inside your mod's folder:

using System.IO;
using System.Text.Json;

private const string SavePath = "scripts/my_mod/profile.json";

private static void SaveProfile(PlayerProfile profile)
{
    try
    {
        string directory = Path.GetDirectoryName(SavePath);
        if (!Directory.Exists(directory))
        {
            Directory.CreateDirectory(directory);
        }

        string json = JsonSerializer.Serialize(profile, new JsonSerializerOptions { WriteIndented = true });
        File.WriteAllText(SavePath, json);
    }
    catch (Exception ex)
    {
        // Never crash the game on save failure: log and continue
        File.AppendAllText("scripts/my_mod/error.log", $"Save failed: {ex.Message}\n");
    }
}

Reading and surviving corrupt data

Reading is where bugs happen: the user edits the JSON by hand and breaks a comma, an antivirus locks the file, or the file does not exist yet because it is the player's first time playing.

Always wrap file deserialization in defensive error handling:

private static PlayerProfile LoadProfile()
{
    try
    {
        // Case 1: First launch -> return default profile cleanly
        if (!File.Exists(SavePath))
        {
            return new PlayerProfile();
        }

        string json = File.ReadAllText(SavePath);
        PlayerProfile loaded = JsonSerializer.Deserialize<PlayerProfile>(json);

        // Case 2: Incompatible version -> discard or migrate
        if (loaded == null || loaded.Version != PlayerProfile.CurrentVersion)
        {
            return new PlayerProfile();
        }

        return loaded;
    }
    catch (Exception ex)
    {
        // Case 3: Corrupted file -> fallback to default without crashing
        File.AppendAllText("scripts/my_mod/error.log", $"Corrupted save recovered: {ex.Message}\n");
        return new PlayerProfile();
    }
}

Notice that LoadProfile never throws an exception out into the game loop. If the file is missing, corrupted, or unreadable, it returns a clean default profile, logs the incident, and lets the player keep playing.

In Project 08, you build a complete persistent faction reputation system.