Execution-client compatibility

EthBFT compatibility is capability- and test-based, not brand-based. A client must expose authenticated chain/block/sync RPCs, capability exchange, and the configured Engine API method profile with specification-conforming payload serialization and status behavior.

Current matrix

Client	Build/validation evidence	Status
Geth	Shanghai single-validator restart and four-validator 3/4 fault-recovery E2E in continuous CI	Reference integration
Reth	Not yet in continuous CI	Candidate
Nethermind	Not yet in continuous CI	Candidate
Besu	Not yet in continuous CI	Candidate
Erigon	Not yet in continuous CI	Candidate

“Candidate” does not mean unsupported by design; it means the project has not yet earned a release-level compatibility claim.

Graduation rule

A client/fork pair becomes supported only after capability negotiation, payload build/validation, transaction inclusion, restart recovery, malformed proposal rejection, and fork-boundary cases pass in continuous CI. Version ranges and known deviations must be recorded here before release.

Hive Engine API suites should be the external conformance baseline. EthBFT's mixed-client network tests must additionally cover the BFT lifecycle and crash boundaries that Engine API conformance alone cannot cover.