Is there any guide available at the moment that explains the process of migrating a parachain back to a solo chain?

Question

I found some guides, like this: https://docs.substrate.io/reference/how-to-guides/parachains/convert-a-solo-chain/ that help you to convert a solo chain to parachain. However, I would like to know if it is possible to leave a relay chain and migrate this parachain to a solo chain and keep its data and state.

The reason behind that is that I don't want to depend on any relay chain for a long time. So, if one day in the future I decided to leave some relay chain I would like to be able to build and finish my own blocks until the moment that I decide to connect again to a new relay chain.

So, do I have to create a new solo chain and migrate the data and state from my Parachain to the new solo chain, or is there a better way to do this?

Answer 1

Kilt has migrated from being a Kusama parachain to a Polkadot parachain. They will likely have the most practical experience regarding this. You can reach out to them and inquire about it.

Answer 2

However, I would like to know if it is possible to leave a relay chain and migrate this parachain to a solo chain and keep its data and state.

It is possible, you would need to do some consensus hard fork. No one has done this before and it would probably be some very chain specific implementation.

So, do I have to create a new solo chain and migrate the data and state from my Parachain to the new solo chain, or is there a better way to do this?

Yes, doing a hardfork as I said above. You will need to have all nodes ready to switch at signal to a new consensus. The signal could for example be some runtime upgrade.