• Starting Setup
• Run Patch Method
• Synthesis State Object
• Typical Simple Code

If you used a Local Solution Patcher to Create a Patcher, then you will have a project that has a minimal basic setup:

public static async Task<int> Main(string[] args)
{
    return await SynthesisPipeline.Instance
        .AddPatch<ISkyrimMod, ISkyrimModGetter>(RunPatch)
        .SetTypicalOpen(GameRelease.SkyrimSE, "YourPatcher.esp")
        .Run(args);
}

public static void RunPatch(IPatcherState<ISkyrimMod, ISkyrimModGetter> state)
{
    //Your code here!
}

The RunPatch method is where the code for your patcher should be located. It will be run when Synthesis is running a pipeline, as well as when your program is started standalone. The method has access to the Synthesis State object, which has much of the information needed to run a patcher.

Whatever changes you want to be made should be applied to the state's PatchMod object.

The state object given to your RunPatch contains several important objects:

• PatchMod: The export patch mod object that all changes should be applied to
• LoadOrder: Object containing all the readonly mod objects on the load order
• LinkCache: Link Cache created from the load order
• ExtraSettingsDataPath: Path where any custom Internal Data will be located

Typical code for a Synthesis patcher consists of locating Winning Overrides for a record type, and adding them to the output patch mod with some changes. Here is a simplistic example:

// Loop over all the winning NPCs in the load order
foreach (var npcGetter in state.LoadOrder.PriorityOrder.Npc().WinningOverrides())
{
    // See if it is a Goblin 
    if (!npcGetter.EditorID?.Contains("Goblin", StringComparison.OrdinalIgnoreCase) ?? true) continue;

    // Add it to the patch
    var npc = state.PatchMod.Npcs.GetOrAddAsOverride(npcGetter);

    // Shrink
    npc.Height /= 2;
}

The above code will shrink any Goblin-named NPCs

Two good resources for learning further details:

• A large catalogue of existing patchers to look at for examples
• In-depth Mutagen documentation found on the Mutagen wiki.