Commit-Boost/commit-boost-client v0.11.0

on GitHub

v0.11.0

v0.11.0 brings SSZ encoding to the Builder API path and adds opt-in WebSocket bid streaming
from relays. It bundles v0.11.0-rc1 to rc3 and includes everything shipped in v0.10.0 and
v0.10.1. Existing configs load unchanged, but read Behaviour changes before upgrading.

Highlights

SSZ for get_header and submit_blinded_block (#466, #467, #468, #481)

• PBS negotiates the response encoding with the beacon node through Accept (q-values
  respected) on get_header and v1 submit_blinded_block. With no preference it returns
  JSON, and it returns 406 when neither SSZ nor JSON is acceptable. v2
  submit_blinded_block returns an empty 202, so Accept is not enforced there.
• Towards relays, PBS asks for SSZ first with JSON as the fallback. What the beacon node
  receives is unaffected, because PBS validates every bid and re-encodes the winner to the
  beacon node's preference.
• submit_blinded_block is sent to relays as SSZ with Eth-Consensus-Version, and is retried
  as JSON only when a relay answers 406 or 415.

WebSocket bid streaming (#483, #499)

• New per-relay option get_header = "stream" (default "http") on [[relays]] and
  [[mux.relays]]. PBS opens
  ws(s)://<relay>/eth/v1/builder/header_stream/{slot}/{parent_hash}/{pubkey}, keeps the
  latest bid until the request deadline or the stream closes, then validates it exactly like
  an HTTP bid.
• If the handshake fails with time left, PBS falls back to a normal HTTP get_header.
• Streaming relays typically require an X-Api-Key (v4 UUID), set in the relay's headers.
  Use the same key consistently for a given relay, since it is sent on every request to
  that relay, including register_validator.
• Stream attempts are recorded under endpoint="get_header_stream", so slots served by the
  HTTP fallback stay distinguishable. There are four new series:
  relay_stream_connect_latency, relay_stream_updates, relay_stream_invalid_frames_total
  and relay_stream_fallback_total.
• Docs: https://commit-boost.github.io/commit-boost-client/ (configuration, "Bid streaming").
  Example config:
  https://github.com/Commit-Boost/commit-boost-client/blob/main/examples/configs/pbs_bid_stream.toml

Relay headers from secret files or env vars (#498)

• Relay header values, such as API keys, can be loaded from a file or an environment variable:
  headers = { X-Api-Key = { file = "/run/secrets/relay-key" } } or
  headers = { X-Api-Key = { env = "RELAY_API_KEY" } }. Literal strings still work.
• Values are re-read on every config reload, so a rotated secret is picked up without a
  restart. Header values are marked sensitive and kept out of debug output. A secret-sourced
  value logs only its source and a short fingerprint.
• commit-boost init mounts file paths read-only into the PBS container and passes env
  variables through. A relative or missing path fails init up front.

Behaviour changes

• No more v2 → v1 fallback on submit_blinded_block. A relay that returns 404 on the v2
  endpoint now fails that submission instead of being retried on v1. It is logged and
  counted in cb_pbs_pbs_submit_block_v2_unsupported_total{relay_id}, and other relays can
  still serve it (#468).
• Error responses to the beacon node now use the Builder API JSON ErrorMessage schema
  instead of plain text (#482; fixes OffchainLabs/prysm#17136).
• Relays now receive SSZ-first requests (see above). Relays without SSZ support get JSON as
  before.
• If dashboards or alerts filter on endpoint="get_header", note that streaming relays now
  report under endpoint="get_header_stream". HTTP relays and the HTTP fallback are
  unchanged.

Fixes

• Custom chains now use their configured fulu_fork_slot. v0.10.x used the slot duration in
  its place, which could label a submitted block with the wrong fork when the beacon node
  omitted Eth-Consensus-Version. The fork of a submitted block is now always derived from
  its slot (#487).
• Relay refusals on submit_blinded_block log the relay's own explanation, and the retry
  count is logged on both the v1 and v2 paths (#502).

Security and dependencies

• rustls 0.23.45 clears RUSTSEC-2026-0285 (#502).
• Sigstore signing action bumped to v3.5.0 (#494).

Also included (shipped in v0.10.0 / v0.10.1)

• Stader validator registry support for mux key loading (#465)
• Lido Curated Module v2 support (#489)
• Dirk signer TLS-provider panic fix (#480)
• SSV node operator ID sent as a numeric uint64 (#474)
• Publish-age cooldown for dependency resolution and --locked builds (#492)

Credits

The SSZ work builds on the original SSZ builder flow by @eserilev (#252) and its port by
@jclapis (#403).