MonoGame.Extended exporter

Output

Each atlas page has a separate TexturePacker-compatible JSON descriptor and image:

atlas.json              atlas_texture.png

The JSON and image form one Texture2DAtlas content asset.

Integrate

Add every JSON descriptor and matching image to the MonoGame Content project. Load each JSON descriptor as a Texture2DAtlas, then create a native sprite by frame name:

var atlas = Content.Load<Texture2DAtlas>("atlas");
var sprite = atlas.CreateSprite("player_0001");

Draw the Sprite with MonoGame.Extended's normal SpriteBatch integration. Keep the generated region names unchanged; animation indices are zero-padded to make name-based lookup stable.

Minimal game

This assumes atlas.json and atlas_texture.png are added to the Content project and the MonoGame.Extended content reader is installed. Replace player_0001 with a frame name that exists in your atlas:

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using MonoGame.Extended.Graphics;

public sealed class DemoGame : Game
{
    private readonly GraphicsDeviceManager graphics;
    private SpriteBatch batch = null!;
    private Sprite sprite = null!;

    public DemoGame() { graphics = new GraphicsDeviceManager(this); }

    protected override void LoadContent()
    {
        batch = new SpriteBatch(GraphicsDevice);
        var atlas = Content.Load<Texture2DAtlas>("atlas");
        sprite = atlas.CreateSprite("player_0001");
    }

    protected override void Draw(GameTime gameTime)
    {
        GraphicsDevice.Clear(Color.CornflowerBlue);
        batch.Begin();
        batch.Draw(sprite, new Vector2(400, 300), 0f, Vector2.One);
        batch.End();
        base.Draw(gameTime);
    }
}

public static class Program
{
    public static void Main() { using var game = new DemoGame(); game.Run(); }
}