Mikhail Kalinin

Optimistic sync is used as a recovery mechanism from the situation when the block tree consistency is broken between CL and EL databases. It could happen when EL client isn't...

Alternatively, we may have `GET /eth/v1/checkpoint/finalized_block_state` returning bundled block and state at the finalized checkpoint, SSZ encoded: ```python class BeaconBlockAndState(Container): block: BeaconBlock state: BeaconState ```

I agree on the port different to what we have for beacon APIs. And I also think that CL clients should have at least the following set of flags: *...

I agree with @mcdee on the following: > this conversation has veered out of scope for an endpoint definition Having these endpoints as part of Beacon API is an option,...

> > More importantly the API proposed here to return a state allows the node to select which state to return whereas the existing API allows any state to be...

Do we want to support two serializations? Does the outcome of introducing e.g. SSZ is so big to maintain both RLP and SSZ or ProtoBuf and SSZ?

We are currently using RLP as it has already been implemented in EthereumJ. I agree that RLP is over complicated in terms of implementation and open for changing it. But...

@AlexeyAkhunov could you, please, outline your thoughts on what requirements both algorithms should satisfy? Maybe you even have some algorithms to take a look at? It would help to get...

> This is only relevant when there's a large enough delay between receiving the message and stamping it "ok" for further distribution - for networks that don't validate messages like...

PR addressing additional fields in `ApplicationPayload`, https://github.com/ethereum/eth2.0-specs/pull/2295