dummy_builder

World's dumbest block builder for Ethereum.

This is a block builder designed with very specific goals, it aims to:

• Return a payload header and un-blinded payload as quickly as possible.
• Satisfy all consensus client safety checks on the payload header, e.g. correct randao, withdrawals, bid value, etc.
• Minimise dependencies and implementation complexity (depends on Lighthouse but not mev-rs).

Non-goals:

• Creating valid payload bodies (!!).

It is designed for use in the blockprint ecosystem where we want a fleet of CL nodes to build a block as quickly as possible with no concern for execution payload validity or quality.

It can also be used for testing block proposal with the builder/mev flow, and should cover the integration points. It's worth noting that the payload will contain an invalid block hash, and the published block will always be rejected by the EL on newPayload.

Quick Start with Docker

dummy_builder utilises the BN to produce payload attributes every slot, e.g. if you're running a Lighthouse beacon node, you'll need to run Lighthouse with --always-prepare-payload and --prepare-payload-lookahead 8000 to get the BN to produce payload attributes every slot (at 4s).

To build the Docker image:

docker build -t dummy_builder .

To start:

docker run -p 18550:18550 -e RUST_LOG=info -v $(pwd)/config.yaml:/app/config.yaml dummy_builder \
  --beacon-node http://docker.host.internal:5052 \
  --payload-value 20000000000000000 \
  --custom-network /app/config.yaml \
  --listen-address 0.0.0.0

This starts dummy_builder on http://localhost:18550. Run dummy_builder --help to see all available options.