v1.9.0-rc2 - 2026-02-10

This is a pre-release for Charon's upcoming v1.9.0. Feedback from early testers is very welcome and appreciated, please use github issues or discord if you have trouble with this release.

For perfect backwards compatibility, Charon users on v1.8.2 and older should add the --feature-set-enable=fetch_only_commidx_0,proposal_timeout as a flag, or CHARON_FEATURE_SET_ENABLE=fetch_only_commidx_0,proposal_timeout as an environment variable to their setups before the nodes in the cluster begin to update to v1.9.0. Alternatively, update all of the nodes in the cluster to this version in close succession.

Read the rest of the release notes for more:

Full Changelog: v1.8.2..v1.9.0-rc2

Promote proposal_timeout feature flag to stable

We have extensively tested the proposal_timeout flag in the past months with numerous DV clusters on mainnet. From this version it is considered stable and moved to default-enabled. Clusters running Charon v1.9.0 will have the first QBFT round for proposal duties set at 1.5s (with second round timing out at 3.5s) in comparison to the current of 1.0s (with second round timing out at 3.0s). There is no urgent need to synchronise upgrades between cluster nodes, as the cluster will reach consensus on whichever timeout threshold of nodes agree on.

Promote fetch_only_commidx_0 feature flag to stable

Post-electra Validator Clients were expected to request data from the beacon node (and hence, the DV) for a hardcoded committee index of 0. However, some clients continued requesting for their specific committee index. This forced Charon to also request the same index from the upstream beacon node(s). Now that this behaviour has been updated in all validator clients supported by Charon, we can promote this opt-in feature flag to stable, reducing the amount of requests we send to a beacon node by up to 64x.

In this issue can be found the list with the minimum required VC version.

Scheduled Duties Cache

This version releases a caching mechanism for validator duties. To save on slow, burdensome requests to a BN, Charon caches them locally. Allowing it to reduce the amount of load on upstream beacon nodes.

Replace operator command

This release adds the ability to directly replace an existing node operator in a cluster, rather than adding, and removing operators sequentially.

Feature

• --nickname flag in charon dkg #4059 (#4105)
• Publish flag for edit commands #4234 (#4235)
• In-url HTTP basic auth for the test commands #4189 (#4251)
• Log the signed head in sync message submission #4247 (#4269)
• Allow DKGs on arbitrary testnets #4052 (#4238)
• Fetch attester data on processed block #4027 (#4095)
• Add amount of pending/successful attestations metrics #4102 (#4248)
• QUIC measurement #4199 (#4239)
• Edit ready private-key-lock-file #4200 (#4226)
• Replace operator command #4126 (#4141)
• Cache VC schedule duties requests #4009 (#4295,#4227)
• Beacon Node peer_id in metrics #4197 (#4264)

Bug

• Charon reports turned off VC's version #4198 (#4225)
• Non-deterministic doubleEagerLinearRoundTimer #4241 (#4243)
• Multiple Pedersen DKG improvements and bugfixes (#4268,#4280,#4281,#4282,#4283,#4298,#4299,#4300,#4301)

Refactor

• Double the DKG timeouts #4272 (#4279)
• Charon run hitting relays when its not going to be able to startup without a cluster lock #4242 (#4255)

Compatibility Matrix

This release of Charon is backwards compatible with Charon >= v1.0., though only v1.7. and newer are Fulu-ready.

The below matrix details a combination of beacon node (consensus layer) + validator clients and their corresponding versions the DV Labs team have tested with this Charon release. More validator and consensus client will be added to this list as they are supported in our automated testing framework.

Legend

• ✅: All duties succeed in testing
• 🟡: All duties succeed in testing, except non-penalised aggregation duties
• 🟠: Duties may fail for this combination
• 🔴: One or more duties fails consistently

What's Changed

• *: removed manifest pb (#4130)

• *: fix some struct names in comments (#4151)

• dkg: fix flaky TestSyncFlow test (#4167)

• *: improved tracing (#4169)

• core/fetcher: update blinded gauge metric values (#4170)

• *: add PAT to github actions (#4174)

• github: remove annotation from tagging in pipelines (#4176)

• github: obol-infrastructure version update on release (#4177)

• *: update prysm repo and bump go-eth2-clinet (#4181)

• core/scheduler: fix builder registration unmarshalling (#4183)

• deps: update libp2p (#4184)

• app: bump version to v1.9-dev (#4192)

• *: fix prepare minor full release (#4193)

• dkg: use slices.Contains to simplify code (#4201)

• cmd: skip inactive validators in exits (#4205)

• *: updated year to 2026 (#4208)

• app/sse: add block processing time metric (#4212)

• deps: fix some struct field names in comment (#4213)

• *: store parsigdb metrics (#4214)

• app: reset feature flag gauge (#4228)

• core: log error when bcast proposal (#4240)

• *: dkg and pk ux improvements (#4246)

• app: add beacon node peer_id metric (#4256)

• github: full versions in yml file (#4259)

• cmd: testnet flags precedence (#4266)

• app/metrics: fix feature flag gauge resetting (#4286)

• app: promote proposal_timeout feature flag to stable (#4296)

• app: promote fetch_only_commidx_0 feature flag to stable (#4297)

• app/version: bump minor version to v1.9-rc (#4311)

• *: v1.9.0 rc2 (#4313)