One letter shorter than subxt and a lot smaller, doing less things by desing.
The main focus of this library is submitting signed extrinsics to your Substrate based chain consuming as little resources as possible to eventually run in the browser and embedded hardware. It will be your responsability to sign extrinsics with a different tool(i.e. libwallet) before you feed the SCALE encoded data to sube.
It supports multiple backends with http being the first one and websockets, some embedded friendly backend or smoldot based light-node likely following.
As additionally planned optional fetaure users will be able to provide an unsigned extrinsic in a human readable format(e.g. JSON) that will be encoded to SCALE making use of the type information available in the chain's (V13) metadata.
For convenience Sube is also a stand-alone cli in case you want to create scripts that submit transactions. Something like this should be possible in the near future.
echo '{"my": "extrinsic"}' | sube encode | wallet sign | sube submit