First of all: Congratulations for creating your own game engine!
You now have to choose: Do you want to use a generic data format or a format customized for your game engine?
I would usually propose to use one of the generic formats already available with TexturePacker. They should already contain all information required to use the sprite sheet.
The other advantage is that there should also be ready-to-use parsers for the data.
TexturePacker currently supports the following generic formats:
TexturePacker's exporter system is template based. You can easily create your own format, including additional customization.
A good starting point is to use one of the existing exporters and adjusting it to your needs. They can be found inside the exporters directory of the TexturePacker installation.
The TexturePacker Online Documentation should give you a good starting point.
We are happy to add your exporter to TexturePacker if you have a public available game framework with a reasonable user base.
Simply contact us at firstname.lastname@example.org and send us a link to your homepage and the exporter.
We support developers creating game engines with free TexturePacker licenses. Our requirement is that the engine is publicly available. It does not need to be open source, it does not need to be free. But people should be able to download and use it.