searcher-builder

Skill is based on Ethereum builder-specs (Builder API), generated at 2026-02-24.

The Builder API lets consensus-layer clients obtain blocks from external builders (proposer-builder separation). It covers validator registration, fetching execution payload headers (bids), submitting signed blinded blocks, and fork-specific types (Bellatrix through Fulu). Use this skill when implementing or integrating with builders, relays, or validator tooling that speak the Builder API.

Core References

Topic	Description	Reference
Builder API overview	Purpose, PBS context, roles, base URL, endpoint summary	core-overview
Endpoints	Validators, getHeader, blinded_blocks v1/v2, status — request/response	core-endpoints
Types and signing	ValidatorRegistration, BuilderBid, SignedBuilderBid, blinded blocks, DOMAIN_APPLICATION_BUILDER	core-types-and-signing

Features

Registration and bidding

Topic	Description	Reference
Validator registration	Eligibility, process_registration, validation rules	features-registration
getHeader and bidding	Bid eligibility, constructing BuilderBid, getHeader semantics	features-get-header-and-bidding
Submit blinded block	v1 vs v2, verification, payload reveal, builder publish	features-submit-blinded-block
Fork versions	Bellatrix/Capella/Deneb/Electra/Fulu bid and payload differences	features-fork-versions

Best Practices

Topic	Description	Reference
Encoding and headers	JSON vs SSZ, Content-Type, Accept, Eth-Consensus-Version, optional headers	best-practices-encoding-and-headers
Bid value verification	Deneb+ excluding withdrawals from bid value, relay verification	best-practices-bid-value-verification