Summary

Now back from Paris, I've been working on a broad research on the Consensus specs. My focus has been on understanding the E2E flow for:

• Attestations
• Slashing
• Fork-choice

I arrived to this simplified sequence chart:

This helped me understand the differences between validator and beacon node responsibilities, which in turn helps divide the tasks in categories/vertical slices. A possible first MVP would be a beacon node working without the validator features.

First vertical slice

This is a rough set of features that could be included in a first e2e vertical slice.

• Beacon Node
  • Process blocks (specially attestations).
  • Update internal state.
• Networking
  • Connect to the p2p network.
  • Receive incoming blocks.
  • Decode SSZ format.
• API
  • Get basic information about specific blocks.

This walking skeleton of a consensus node can enable us to add other features on top of it, like fork-choice, slashing, and other features.

Feature list

The work was divided the work into categories:

• Core (beacon)
  • Fork-choice
  • Block representation (e.g. proto-arrays)
  • Attestation processing
  • Slashing processing
  • State Storage
• Validator
  • Attestation creation
  • Slashing monitoring
  • Slashing proof creation
• EngineAPI
  • Getting execution payloads
  • Payload execution
  • Block validation
  • Fork choice updates
• LibP2P
  • Discovery
  • Receiving blocks
  • Receiving pending attestations
  • Propagating attestations
  • Propagating slashings
• SSZ: decoding payloads
• BSL: verifying signatures
• Grafana dashboards
• CI:
  • spec tests -> We'll focus on these ones.
  • integration tests
  • unit tests

This week we'll take these features, understand inter-dependencies, estimate the time they'll, write tickets and build a roadmap.

Repo setup

As a basic maintenance task, I setup the elixir project in our repo, plus make targets for basic tasks. This week I'll add linter, CI, and other kickoff tasks.

Resources

My main sources of information were:

• Ben Edgington's Upgrading Ethereum book.
• Vitalik's Annotated Consensus Specs.