Frog Data Library Download

Lightweight data persistence framework for YAPYAP Mods.

Frog Data Library is a modular data persistence system that allows YAPYAP mod developers to safely save and load custom data without polluting vanilla save files.

Instead of injecting data into the game’s save structure, FrogDataLib stores mod data in external “sidecar” files that stay synchronized with the player’s active save slot.

FEATURES

Zero Save Pollution

Stores mod data in:
%AppData%/LocalLow/maisonbap/YAPYAP/FrogData/
Keeps vanilla save files clean and untouched

Automatic Slot Synchronization

Automatically handles:

Saving
Loading
Deleting

Data stays tied to the currently active save slot.

Type-Safe Design

Uses a generic pattern:
FrogDataContainer<T>
Strongly typed serialization for safer development

Corrupt-Data Protection (Frog Sentinel)

Uses an internal sentinel value: 8675309
Detects silent Unity JsonUtility deserialization failures
Prevents saving/loading if serialization fails

Two-Tier Deserialization

Internally stores mod data as strings
Serializes only when needed
Prevents TypeLoadException issues when modifying mods on an active save. Still not recommended to change data models mid-save.

Developer Guide

Define Your Data Model

Your data class must:

Inherit from FrogDataModel
Be marked with [Serializable]

using FrogDataLib.DataManagement;
using System;

[Serializable]
public class MyModData : FrogDataModel
{
    public int PlayerKills;
    public string FavoriteFrogName;
}

Initialize the Container

Create a container using a unique GUID (usually your mod ID).

private FrogDataContainer<MyModData> _dataContainer;

void Awake()
{
    _dataContainer = new FrogDataContainer<MyModData>("com.yourname.mymod");
    
    FrogDataManager.OnBeginSaving += SaveMyData;
    FrogDataManager.OnLoadCompleted += LoadMyData;
}

Use Your Data Normally

myData.FavoriteFrogName = "Gertrude";

Saving and Loading

Use FrogDataLib’s built-in events to stay synchronized with the game session.

// Called when the player clicks "Save"
private void SaveMyData() =>
    _dataContainer.SaveModData(myData);

// Called after a save slot finishes loading
private void LoadMyData()
{
    MyModData data = _dataContainer.GetModData();
    Debug.Log($"Loaded: {data.FavoriteFrogName}");
}

Important Notes

Frog Sentinel

If your model is not marked [Serializable], Unity’s JsonUtility may silently fail.

In this case:

Sentinel value becomes 0
FrogDataLib blocks saving/loading
Prevents accidental data loss

Session Cleanup

Use the OnSessionEnded event to clear cached variables when returning to the Main Menu.

Click to see example project

using BepInEx;
using BepInEx.Logging;
using FrogDataLib.DataManagement;

namespace StarterKit;

[BepInAutoPlugin]
public partial class StarterKitPlugin : BaseUnityPlugin
{
  internal static ManualLogSource Log { get; private set; }

  private void Awake()
  {
    Log = Logger;
    Log.LogInfo($"Plugin {Name} is loaded!");

    /*
      This is how you manage a data container for your mod
      For simplicity's sake I will use inline anonymous actions
      to talk to FrogDataManager but I imagine it would be
      far better to use full methods and actually store your
      container in a field or property in a dedicated class
    */

    /*
      Note that we pass our GUID in here and use our ExampleData
      Type as the generic type argument when creating the container
    */
    var cont = new FrogDataContainer<ExampleData>(Id);

    //We create our default data for the save here
    ExampleData data = new();

    //Now we register with FrogDataManager for callbacks
    FrogDataManager.OnBeginSaving += () =>
    {
      Log.LogMessage("Saving my data");
      cont.SaveModData(data);
    };

    FrogDataManager.OnLoadCompleted += () =>
    {
      Log.LogMessage("Loading my data");
      data = cont.GetModData();
    };

    FrogDataManager.OnSessionEnded += () =>
    {
      /*
        Actually we don't need to do anything for such a simple
        example but this is where you'd do any cleanup because
        the user is returning to the main menu.
      */
      Log.LogMessage("Cleaning up my data :)");
    };
  }
}

Requires: BepInEx 5

Official Github page

If you have any problems installing this or any other mod for YAPYAP, read this guide.