I'd like to start developing a solution targeting the Ethereum blockchain but I want to target the Ethereum 2.0 blockchain and I'm not so interested in 1.0 anymore. Can I already do the development using the current web3.js library? Is there an ETH2.0 version? Or perhaps a more low-level solution I can already use for ETH2.0? (JSON RPC API)
Unfortunately web3.js is not compatible with Eth2 APIs.
Eth1 and Eth2 are quite different; they have very different data models for blocks and Eth2 is going to use RESTful HTTP instead of JSON-RPC. I don't expect to see web3.js compatibility anytime soon.
At the present time (mid-April 2020) there is no standard API defined for Ethereum 2.0, however there is a standardisation movement taking place at https://github.com/ethereum/eth2.0-APIs.
Some clients have published their (widely differing) APIs already:
- Lighthouse (I contribute here): https://lighthouse-book.sigmaprime.io/api.html
- Prysm: https://github.com/prysmaticlabs/ethereumapis/
I know Lighthouse will move to match whatever is agreed upon at ethereum/eth2.0-APIs and it seems like other clients will do the same.