## Description
Omit null `witness` field from payload envelope.
## Motivation
Currently, JSON encoded payload types always include `"witness": null`,
which, I believe, is not intentional.
This implements recent changes to EIP-7685, EIP-6110, and
execution-apis.
---------
Co-authored-by: lightclient <lightclient@protonmail.com>
Co-authored-by: Shude Li <islishude@gmail.com>
This PR integrates witness-enabled block production, witness-creating
payload execution and stateless cross-validation into the `engine` API.
The purpose of the PR is to enable the following use-cases (for API
details, please see next section):
- Cross validating locally created blocks:
- Call `forkchoiceUpdatedWithWitness` instead of `forkchoiceUpdated` to
trigger witness creation too.
- Call `getPayload` as before to retrieve the new block and also the
above created witness.
- Call `executeStatelessPayload` against another client to
cross-validate the block.
- Cross validating locally processed blocks:
- Call `newPayloadWithWitness` instead of `newPayload` to trigger
witness creation too.
- Call `executeStatelessPayload` against another client to
cross-validate the block.
- Block production for stateless clients (local or MEV builders):
- Call `forkchoiceUpdatedWithWitness` instead of `forkchoiceUpdated` to
trigger witness creation too.
- Call `getPayload` as before to retrieve the new block and also the
above created witness.
- Propagate witnesses across the consensus libp2p network for stateless
Ethereum.
- Stateless validator validation:
- Call `executeStatelessPayload` with the propagated witness to
statelessly validate the block.
*Note, the various `WithWitness` methods could also *just be* an
additional boolean flag on the base methods, but this PR wanted to keep
the methods separate until a final consensus is reached on how to
integrate in production.*
---
The following `engine` API types are introduced:
```go
// StatelessPayloadStatusV1 is the result of a stateless payload execution.
type StatelessPayloadStatusV1 struct {
Status string `json:"status"`
StateRoot common.Hash `json:"stateRoot"`
ReceiptsRoot common.Hash `json:"receiptsRoot"`
ValidationError *string `json:"validationError"`
}
```
- Add `forkchoiceUpdatedWithWitnessV1,2,3` with same params and returns
as `forkchoiceUpdatedV1,2,3`, but triggering a stateless witness
building if block production is requested.
- Extend `getPayloadV2,3` to return `executionPayloadEnvelope` with an
additional `witness` field of type `bytes` iff created via
`forkchoiceUpdatedWithWitnessV2,3`.
- Add `newPayloadWithWitnessV1,2,3,4` with same params and returns as
`newPayloadV1,2,3,4`, but triggering a stateless witness creation during
payload execution to allow cross validating it.
- Extend `payloadStatusV1` with a `witness` field of type `bytes` if
returned by `newPayloadWithWitnessV1,2,3,4`.
- Add `executeStatelessPayloadV1,2,3,4` with same base params as
`newPayloadV1,2,3,4` and one more additional param (`witness`) of type
`bytes`. The method returns `statelessPayloadStatusV1`, which mirrors
`payloadStatusV1` but replaces `latestValidHash` with `stateRoot` and
`receiptRoot`.
This is a spin-out from the EIP-4844 devnet branch, containing just the Engine API modifications
and nothing else. The newPayloadV3 endpoint won't really work in this version, but we need the
data structures for testing so I'd like to get this in early.
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
This PR moves core/beacon to beacon/engine so that beacon-chain related code has its own top level package which also can house the the beacon lightclient-code.
