v1.9.0-rc2

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.

Note

This feature flag can be manually turned off by setting the --feature-set-disable=proposal_timeout flag.

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.

Note

This feature flag can be manually turned off by setting --feature-set-disable=fetch_only_commidx_0 flag.

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.

Note

If there are any issues spotted with scheduled duty caching, it can be turned off by setting the --feature-set-enable=disable_duties_cache feature flag.

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.

Warning

Charon's editability features are relatively new. Use them with caution, and practice actions on a testnet before mainnet. Flag any confusion or difficulties with User Experience to an Obol Core team member.

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

Validator 👉 Consensus 👇	Teku v26.2.0	Lighthouse v8.1.0	Lodestar v1.40.0	Nimbus v26.1.0	Prysm v7.1.2	Vouch v1.12.0	Remarks
Teku v26.2.0	⏳	⏳	⏳	⏳	⏳	⏳
Lighthouse v8.1.0	⏳	⏳	⏳	⏳	⏳	⏳
Lodestar v1.40.0	⏳	⏳	⏳	⏳	⏳	⏳
Nimbus v26.1.0	⏳	⏳	⏳	⏳	⏳	⏳
Prysm v7.1.2	⏳	⏳	⏳	⏳	⏳	⏳
Grandine v2.0.1	⏳	⏳	⏳	⏳	⏳	⏳

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)

v1.8.2

v1.8.2 - 2026-02-09

This is non-urgent but recommended patch release of Charon v1.8.1. This patch removes an unnecessary dependency on MEV-registration for proposals in slot 0 of an epoch, to improve proposal performance for large clusters using certain relays. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Read the rest of the release notes for more:

Full Changelog: v1.8.1..v1.8.2

Features

• Asynchronous builder registration #4271

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

Validator 👉 Consensus 👇	Teku v25.12.0 ❗	Lighthouse v8.0.1	Lodestar v1.38.0	Nimbus v25.11.1	Prysm v7.1.0	Vouch 1.12.0 ❗
Teku v25.12.0 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.1	✅	✅	✅	✅	✅	🟡
Lodestar v1.38.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.11.1	✅	✅	✅	✅	✅	🟡
Prysm v7.1.0	✅	✅	✅	✅	✅	🟡
Grandine v2.0.1	✅	✅	✅	✅	✅	🟡

What's Changed

• *: cherry pick async builder (#4292)

• app/version: bump to v1.8-rc (#4294)

• app/version: bump v1.8 to stable (#4302)

v1.8.1

v1.8.1 - 2026-01-07

This is not required, non-urgent patch release for Charon v1.8.0. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Read the rest of the release notes for more:

Full Changelog: v1.8.0..v1.8.1

Features

• Ignore non-active validators on charon exit sign --all and charon exit broadcast --all #4205

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

Validator 👉 Consensus 👇	Teku v25.12.0 ❗	Lighthouse v8.0.1	Lodestar v1.38.0	Nimbus v25.11.1	Prysm v7.1.0	Vouch 1.12.0 ❗
Teku v25.12.0 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.1	✅	✅	✅	✅	✅	🟡
Lodestar v1.38.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.11.1	✅	✅	✅	✅	✅	🟡
Prysm v7.1.0	✅	✅	✅	✅	✅	🟡
Grandine v2.0.1	✅	✅	✅	✅	✅	🟡

What's Changed

• app/version: bump to v1.8-rc (#4206)

• *: v1.8.1 rc1 (#4207)

• app/version: bump v1.8 to stable (#4210)

v1.8.0

v1.8.0 - 2025-12-17

This is Charon's v1.8.0 release. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Partial deposit submission and retrieval

Support for submitting and fetching partial validator deposits via the new charon deposit sign and charon deposit fetch commands. This enables operators to update deposit data for validators after cluster creation but before activation.

This feature is particularly useful for large clusters where only a subset of validators are activated initially, and business or operational requirements may change over time. Operators can re-sign updated deposit data, with partial signatures aggregated once a threshold is reached, after which the full deposit data can be retrieved with charon deposit fetch or from the Obol API.

Read the rest of the release notes for more:

Full Changelog: v1.7.3..v1.8.0

Feature

• charon deposit sign && charon deposit fetch #3992 (#4032)
• Update minimum version warning log for fusaka fork #3978 (#4000)
• Track blinded/unblinded block building from the BN #4106 (#4117)
• Add Date-Milliseconds and X-Timeout-Ms to charon alpha test mev #4045 (#4074)

Bug

• Unknown git hash in Charon v1.5.2 pre-built binary #4001 (#4057)
• Signed block fetcher retries on missed blocks #4035 (#4041)

Refactor

• Catch HTTP 409 Duplicate Request gracefully in charon dkg --publish #4107 (#4121)
• Errors revamp #3882 (#4050,#4044,#4046,#4047,#4038)
• Remove the pretty key from JSON logging #3924 (#4005)
• Move chain split check to pre-prepare round (#4011)
• Add eth2wrap logic to proxy (#4042)]
• Builder registration redesign (#4060)

Test

• Rework all disabled and removed tests #3988 (#4064,#4063,#4062,#4058)

Misc

• Automate release with pipelines #3933 (#4125,#4101,#4084,#4100)

Compatibility Matrix

This release of Charon is backwards compatible with Charon v1.0.*, v1.1.*, v1.2.0, v1.3.*, v1.4.*, v1.5.*, v1.6.*, v1.7.*. Though only v1.3.* and newer are Pectra-ready and 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

Validator 👉 Consensus 👇	Teku v25.12.0 ❗	Lighthouse v8.0.1	Lodestar v1.38.0	Nimbus v25.11.1	Prysm v7.1.0	Vouch 1.12.0 ❗
Teku v25.12.0 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.1	✅	✅	✅	✅	✅	🟡
Lodestar v1.38.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.11.1	✅	✅	✅	✅	✅	🟡
Prysm v7.1.0	✅	✅	✅	✅	✅	🟡
Grandine v2.0.1	✅	✅	✅	✅	✅	🟡

Note

There is currently an incompatibility between validator clients that may cause attestation aggregation duties to fail. Aggregation duties are not economically rewarded nor punished for their completion.

To ensure aggregations succeed; have at least threshold of nodes in the cluster running one of Lodestar, Lighthouse, and Nimbus, or alternatively; have a threshold of nodes in the cluster running one of Teku and Prysm. This incompatibility will be remediated in upcoming client releases.

Warning

Lodestar's validator client's default behaviour in version <v1.37.0 is to skip the next slot if it fails an attestation or aggregation. This can impact your cluster's performance, particularly if you have more than the fault tolerance threshold of your cluster running Lodestar's validator client, and many validators running in the cluster. This has been fixed in v1.37.0.

If your cluster is not successfully aggregating, you should ideally swap to a set of compatible validator clients listed above, along with ensuring your clients have the appropriate --distributed flag set to enable distributed aggregation mode.

What's Changed

• app: bump version from 1.7-dev to 1.8-dev (#3998)

• *: bump go-eth2-client v0.27.1 (#4002)

• docs: fix some a/an issues (#4007)

• qbft: move chain split check to preprepare round (#4011)

• cmd: update docker flags and api url in create dkg (#4024)

• *: replace context.WithCancel with t.Context (#4026)

• app/sse: fix bucket delay values (#4029)

• cmd: use WaitGroup.Go to simplify code (#4033)

• *: fix some minor issues (#4036)

• *: claude init (#4037)

• *: various optimizations (#4039)

• core/validatorapi: add eth2wrap logic to proxy (#4042)

• *: replace Split in loops with more efficient SplitSeq (#4043)

• *: function comments revamp (#4048)

• *: replace sort.Slice with slices.Sort for natural ordering (#4054)

• *: builder reg redesign (#4060)

• Bump golangci-lint v2.6.1 (#4075)

• eth2util/rlp: fixed wrong condition (#4087)

• cmd: relay override for add-vals (#4091)

• cluster: fix incorrect function name in comment (#4097)

• cluster: fixed testdata (#4124)

• core: fix incorrect struct name in comment (#4135)

• core/validatorapi: support proxy of SSE events (#4140)

• *: bump golangci-lint v2.6.2 (#4142)

• dkg: fixed edit remove-operators (#4147)

• *: new github actions user (#4152)

• *: add base64 decode to relase scripts (#4158)

• *: add check-latest to setup-go (#4159)

• app/version: bump minor version to v1.8-rc (#4160)

• *: cherry pick for 1.8.0 (#4173)

• *: v1.8.0-rc2 (#4178)

• *: v1.8.0-rc2 (#4182)

• *: cherry pick for v1.8.0 (#4185)

• app/version: bump v1.8 to stable (#4191)

v1.7.3

v1.7.3 - 2025-12-12

This is recommended, but not required, non-urgent patch release for Charon v1.7.3. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Read the rest of the release notes for more:

Full Changelog: v1.7.2..v1.7.3

Features

• Add new core_fetcher_proposal_blinded metric #4117

Compatibility Matrix

This release of Charon is backwards compatible with Charon v1.0.*, v1.1.*, v1.2.0, v1.3.*, v1.4.*, v1.5.*, v1.6.*, v1.7.* Though only v1.3.* and newer are Pectra-ready and 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

Validator 👉 Consensus 👇	Teku v25.10.0 ❗	Lighthouse v8.0.0	Lodestar v1.37.0	Nimbus v25.9.2	Prysm v6.1.3	Vouch 1.12.0 ❗
Teku v25.10.0 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.0	✅	✅	✅	✅	✅	🟡
Lodestar v1.37.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.9.2	✅	✅	✅	✅	✅	🟡
Prysm v6.1.3	✅	✅	✅	✅	✅	🟡
Grandine v2.0.0	✅	✅	✅	✅	✅	🟡

Note

There is currently an incompatibility between validator clients that may cause attestation aggregation duties to fail. Aggregation duties are not economically rewarded nor punished for their completion.

To ensure aggregations succeed; have at least threshold of nodes in the cluster running one of Lodestar, Lighthouse, and Nimbus, or alternatively; have a threshold of nodes in the cluster running one of Teku and Prysm. This incompatibility will be remediated in upcoming client releases.

Warning

Lodestar's validator client's default behaviour in version <v1.37.0 is to skip the next slot if it fails an attestation or aggregation. This can impact your cluster's performance, particularly if you have more than the fault tolerance threshold of your cluster running Lodestar's validator client, and many validators running in the cluster. This has been fixed in v1.37.0.

If your cluster is not successfully aggregating, you should ideally swap to a set of compatible validator clients listed above, along with ensuring your clients have the appropriate --distributed flag set to enable distributed aggregation mode.

What's Changed

• *: cherry pick for 1.7.3 (#4172)

v1.7.2

v1.7.2 - 2025-12-05

This is recommended, but not required, non-urgent patch release for Charon v1.7.1. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Read the rest of the release notes for more:

Full Changelog: v1.7.1..v1.7.2

Features

• Add new core_fetcher_proposal_blinded metric #4117

Compatibility Matrix

This release of Charon is backwards compatible with Charon v1.0.*, v1.1.*, v1.2.0, v1.3.*, v1.4.*, v1.5.*, v1.6.*, v1.7.* Though only v1.3.* and newer are Pectra-ready and 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

Validator 👉 Consensus 👇	Teku v25.10.0 ❗	Lighthouse v8.0.0-rc.2	Lodestar v1.35.0	Nimbus v25.9.2	Prysm v6.1.3	Vouch 1.12.0-beta.3 ❗
Teku v25.10.0 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.0-rc.2	✅	✅	✅	✅	✅	🟡
Lodestar v1.35.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.9.2	✅	✅	✅	✅	✅	🟡
Prysm v6.1.3	✅	✅	✅	✅	✅	🟡
Grandine v2.0.0.rc0	✅	✅	✅	✅	✅	🟡

Note

There is currently an incompatibility between validator clients that may cause attestation aggregation duties to fail. Aggregation duties are not economically rewarded nor punished for their completion.

To ensure aggregations succeed; have at least threshold of nodes in the cluster running one of Lodestar, Lighthouse, and Nimbus, or alternatively; have a threshold of nodes in the cluster running one of Teku and Prysm. This incompatibility will be remediated in upcoming client releases.

Warning

Lodestar's validator client's default behaviour is to skip the next slot if it fails an attestation or aggregation. This can impact your cluster's performance, particularly if you have more than the fault tolerance threshold of your cluster running Lodestar's validator client, and many validators running in the cluster.

If your cluster is not successfully aggregating, you should ideally swap to a set of compatible validator clients listed above, along with ensuring your clients have the appropriate --distributed flag set to enable distributed aggregation mode.

What's Changed

• *: cherry picking blinded metric (#4129)

• app/version: bump v1.7 to stable (#4145)

v1.7.1

v1.7.1 - 2025-10-23

This is recommended, but not required, non-urgent patch release for Charon v1.7.0. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Fulu Activation Schedule

Please consult the official Ethereum blog for the latest client versions to run ahead of the hardfork.

Network	Hardfork Date
Holesky	Completed
Sepolia	Completed
Hoodi	October 28th 2025 18:53:12 UTC
Mainnet	December 3rd 2025 (Estimated)

Warning

Failure to update all your client versions before the hardfork date could cause your validator to go offline, or worse.

Read the rest of the release notes for more:

Full Changelog: v1.7.0..v1.7.1

Bugfixes

• Fix bucket delay values #4029
• Update docker flags and api url in create dkg #4024
• Handle 404 errors gracefully for signed blocks on inclusion check #4041

Compatibility Matrix

This release of Charon is backwards compatible with Charon v1.0.*, v1.1.*, v1.2.0, v1.3.*, v1.4.*, v1.5.*, v1.6.*, v1.7.* Though only v1.3.* and newer are Pectra-ready and 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

Validator 👉 Consensus 👇	Teku v25.10.0 ❗	Lighthouse v8.0.0-rc.2	Lodestar v1.35.0	Nimbus v25.9.2	Prysm v6.1.3	Vouch 1.12.0-beta.3 ❗
Teku v25.10.0 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.0-rc.2	✅	✅	✅	✅	✅	🟡
Lodestar v1.35.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.9.2	✅	✅	✅	✅	✅	🟡
Prysm v6.1.3	✅	✅	✅	✅	✅	🟡
Grandine v2.0.0.rc0	✅	✅	✅	✅	✅	🟡

Note

There is currently an incompatibility between validator clients that may cause attestation aggregation duties to fail. Aggregation duties are not economically rewarded nor punished for their completion.

To ensure aggregations succeed; have at least threshold of nodes in the cluster running one of Lodestar, Lighthouse, and Nimbus, or alternatively; have a threshold of nodes in the cluster running one of Teku and Prysm. This incompatibility will be remediated in upcoming client releases.

Warning

Lodestar's validator client's default behaviour is to skip the next slot if it fails an attestation or aggregation. This can impact your cluster's performance, particularly if you have more than the fault tolerance threshold of your cluster running Lodestar's validator client, and many validators running in the cluster.

If your cluster is not successfully aggregating, you should ideally swap to a set of compatible validator clients listed above, along with ensuring your clients have the appropriate --distributed flag set to enable distributed aggregation mode.

What's Changed

• *: v1.7.1 (#4049)

v1.7.0

v1.7.0 - 2025-10-08

This is Charon's first Fulu-ready version. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Fulu Activation Schedule

Please consult the official Ethereum blog for the latest client versions to run ahead of the hardfork.

Network	Hardfork Date
Holesky	Completed
Sepolia	October 14th 2025 07:36:00 UTC
Hoodi	October 28th 2025 18:53:12 UTC
Mainnet	December 3rd 2025 (Estimated)

Warning

Failure to update all your client versions before the hardfork date could cause your validator to go offline, or worse.

Apart from Fulu readiness, there are two major features in this release, both under feature flags:

Chain Split Safety Halt

If the feature flag chain_split_halt is enabled (--feature-set-enable=chain_split_halt), Charon nodes will verify that the target and source votes (FFG) of the attestation a consensus leader proposes to sign matches with their local beacon node's view of the network. If they differ, it means that the nodes are on different chains(forks). Charon will not progress consensus with a leader on a different fork, leading to a timeout and a new leader being chosen.

This means that if more than the fault tolerance of the cluster are on different chains(forks), the cluster will stop attesting until a threshold of nodes are on the same chain. This feature may protect your cluster in worst case slashing situations where a supermajority of nodes attest to the wrong chain. If your cluster does not have those faulty clients as a supermajority amongst its operators, and the opt-in feature is enabled, your cluster will halt rather than incorrectly attest and be doomed to slashing or activity leaking 100% of your principal.

Performance Improvement

Fetch only attestation data with committee index 0 (--feature-set-enable=fetch_only_commidx_0). In Electra the spec for fetching attestation data was changed, hardcoding the committee_index in the request to 0. However, most validator clients continued asking for the specific committee index, while the beacon nodes disregarded this field and returned the data. On Charon we are forced to make both requests in order to accommodate both behaviors in validator clients. Now, most VCs have updated their implementations, and we are releasing opt-in support for the performance improvement, if you confirm your VC supports the behaviour.

If you enable this feature flag you will reduce the amount of requests Charon sends to the beacon node for attestation data. For big clusters that might be as high as 63 requests less per slot. In big clusters with slower beacon nodes turning on this feature flag may improve attestation and efficiency rates.

Confirm in this linked issue for the latest info on whether validator client version is new enough to enable this feature. These release notes may not have the latest status on VC support.

Validator Client	Supports This Feature Since
Lodestar	> v1.33.0 🟢
Nimbus	> v25.3.1 🟢
Prysm	> v6.1.0 🟢
Teku	> 25.9.0 🟢
Lighthouse	Unimplemented. Issue here. 🔴
Vouch	Unimplemented. 🔴

Once all VCs request the correct committee index, this feature will be default-on in a future version of Charon.

Read the rest of the release notes for more:

Full Changelog: v1.6.1..v1.7.0

Feature

• Attestation source and target vote consensus - chain split halt #3876 #4011 (#3946)
• Fetcher fetch only attestation data with committee index 0 #3980 (#3989)
• Track SSE events block_gossip and block #3877 (#3938)
• Add publishing new cluster definition to Obol API with only --operator-enrs #3993
• Allow beacon node basic auth in URL #3926

Misc

• Turned on feature flag metric #3979 (#3994)
• Add self identification to logs #3919 (#3939)
• Allow pushing metrics to OTLP insecurely #3983
• Remove the pretty key from JSON logging #3924 (#4005)

Compatibility Matrix

This release of Charon is backwards compatible with Charon v1.0.*, v1.1.*, v1.2.0, v1.3.*, v1.4.*, v1.5.*, v1.6.* Though only v1.3.* and newer are Pectra-ready and none of the previous 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

Validator 👉 Consensus 👇	Teku v25.9.3 ❗	Lighthouse v8.0.0-rc.0 v8.0.0-rc.1	Lodestar v1.35.0-rc.0 v1.35.0	Nimbus v25.9.1 v25.9.2	Prysm v6.1.0 v6.1.2	Vouch 1.12.0-beta.3 ❗
Teku v25.9.3 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.0-rc.0 v8.0.0-rc.1	✅	✅	✅	✅	✅	🟡
Lodestar v1.35.0-rc.0 v1.35.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.9.1 v25.9.2	✅	✅	✅	✅	✅	🟡
Prysm v6.1.0 v6.1.2	🟠✅	✅	✅	✅	✅	🟡
Grandine v2.0.0.rc0	✅	✅	✅	✅	✅	🟡

Note

There is currently an incompatibility between validator clients that may cause attestation aggregation duties to fail. Aggregation duties are not economically rewarded nor punished for their completion.

To ensure aggregations succeed; have at least threshold of nodes in the cluster running one of Lodestar, Lighthouse, and Nimbus, or alternatively; have a threshold of nodes in the cluster running one of Teku and Prysm. This incompatibility will be remediated in upcoming client releases.

Warning

Lodestar's validator client's default behaviour is to skip the next slot if it fails an attestation or aggregation. This can impact your cluster's performance, particularly if you have more than the fault tolerance threshold of your cluster running Lodestar's validator client, and many validators running in the cluster.

If your cluster is not successfully aggregating, you should ideally swap to a set of compatible validator clients listed above, along with ensuring your clients have the appropriate --distributed flag set to enable distributed aggregation mode.

What's Changed

• app/version: bump to v1.7-dev (#3889)

• cmd: add hostname verification (#3901)

• cmd: renamed add-validators flags (#3902)

• dkg: add zipped flag (#3903)

• core: replace context.WithCancel with t.Context (#3905)

• *: bump go to v1.25 (#3910)

• app: fix some inconsistent function name in comment (#3912)

• *: added otlp headers (#3915)

• p2p: error on closing canceled stream (#3916)

• *: bump govulncheck to v1.1.4 (#3922)

• app: fallback buildinfo logic (#3930)

• *: codebase typos and spelling checked (#3936)

• core/fetcher: improve fee recipient checking (#3937)

• cmd: add missing space (#3957)

• p2p: separate peer and relay p2p metrics (#3971)

• [dutydb: check only source and target for commidx 0 (#...

v1.7.0-rc4

v1.7.0-rc4 - 2025-10-06

This is Charon's first Fulu-ready pre-release version. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Fulu Activation Schedule

Please consult the official Ethereum blog for the latest client versions to run ahead of the hardfork.

Network	Hardfork Date
Holesky	Completed
Sepolia	October 14th 2025 07:36:00 UTC
Hoodi	October 28th 2025 18:53:12 UTC
Mainnet	December 3rd 2025 (Estimated)

Warning

Failure to update all your client versions before the hardfork date could cause your validator to go offline, or worse.

Apart from Fulu readiness, there are two major features in this release, both under feature flags:

Chain Split Safety Halt

If the feature flag chain_split_halt is enabled (--feature-set-enable=chain_split_halt), Charon nodes will verify that the target and source votes (FFG) of the attestation a consensus leader proposes to sign matches with their local beacon node's view of the network. If they differ, it means that the nodes are on different chains(forks). Charon will not progress consensus with a leader on a different fork, leading to a timeout and a new leader being chosen.

This means that if more than the fault tolerance of the cluster are on different chains(forks), the cluster will stop attesting until a threshold of nodes are on the same chain. This feature may protect your cluster in worst case slashing situations where a supermajority of nodes attest to the wrong chain. If your cluster does not have those faulty clients as a supermajority amongst its operators, and the opt-in feature is enabled, your cluster will halt rather than incorrectly attest and be doomed to slashing or activity leaking 100% of your principal.

Performance Improvement

Fetch only attestation data with committee index 0 (--feature-set-enable=fetch_only_commidx_0). In Electra the spec for fetching attestation data was changed, hardcoding the committee_index in the request to 0. However, most validator clients continued asking for the specific committee index, while the beacon nodes disregarded this field and returned the data. On Charon we are forced to make both requests in order to accommodate both behaviors in validator clients. Now, most VCs have updated their implementations, and we are releasing opt-in support for the performance improvement, if you confirm your VC supports the behaviour.

If you enable this feature flag you will reduce the amount of requests Charon sends to the beacon node for attestation data. For big clusters that might be as high as 63 requests less per slot. In big clusters with slower beacon nodes turning on this feature flag may improve attestation and efficiency rates.

Confirm in this linked issue for the latest info on whether validator client version is new enough to enable this feature. These release notes may not have the latest status on VC support.

Validator Client	Supports This Feature Since
Lodestar	> v1.33.0 🟢
Nimbus	> v25.3.1 🟢
Prysm	> v6.1.0 🟢
Teku	> 25.9.0 🟢
Lighthouse	Unimplemented. Issue here. 🔴
Vouch	Unimplemented. 🔴

Once all VCs request the correct committee index, this feature will be default-on in a future version of Charon.

Read the rest of the release notes for more:

Full Changelog: v1.6.1..v1.7.0-rc4

Feature

• Attestation source and target vote consensus - chain split halt #3876 #4011 (#3946)
• Fetcher fetch only attestation data with committee index 0 #3980 (#3989)
• Track SSE events block_gossip and block #3877 (#3938)
• Add publishing new cluster definition to Obol API with only --operator-enrs #3993
• Allow beacon node basic auth in URL #3926

Misc

• Turned on feature flag metric #3979 (#3994)
• Add self identification to logs #3919 (#3939)
• Allow pushing metrics to OTLP insecurely #3983
• Remove the pretty key from JSON logging #3924 (#4005)

Compatibility Matrix

This release of Charon is backwards compatible with Charon v1.0.*, v1.1.*, v1.2.0, v1.3.*, v1.4.*, v1.5.*, v1.6.* Though only v1.3.* and newer are Pectra-ready and none of the previous 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

Validator 👉 Consensus 👇	Teku v25.9.3 ❗	Lighthouse v8.0.0-rc.0	Lodestar v1.35.0-rc.0	Nimbus v25.9.1	Prysm v6.1.0	Vouch 1.12.0-beta.3 ❗
Teku v25.9.3 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.0-rc.0	✅	✅	✅	✅	✅	🟡
Lodestar v1.35.0-rc.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.9.1	✅	✅	✅	✅	✅	🟡
Prysm v6.1.0	🟠	✅	✅	✅	✅	🟡
Grandine v2.0.0.rc0	✅	✅	✅	✅	✅	🟡

What's Changed

• app/version: bump to v1.7-dev (#3889)

• cmd: add hostname verification (#3901)

• cmd: renamed add-validators flags (#3902)

• dkg: add zipped flag (#3903)

• core: replace context.WithCancel with t.Context (#3905)

• *: bump go to v1.25 (#3910)

• app: fix some inconsistent function name in comment (#3912)

• *: added otlp headers (#3915)

• p2p: error on closing canceled stream (#3916)

• *: bump govulncheck to v1.1.4 (#3922)

• app: fallback buildinfo logic (#3930)

• *: codebase typos and spelling checked (#3936)

• core/fetcher: improve fee recipient checking (#3937)

• cmd: add missing space (#3957)

• p2p: separate peer and relay p2p metrics (#3971)

• dutydb: check only source and target for commidx 0 (#3974)

• *: otlp insecure flag (#3983)

• *: bump go-eth2-client to v0.27.0-obol.1 (#3985)

• *: bump golangci-lint to v2.5.0 (#3986)

• cmd: cleanup (#3990)

• *: allow --operator-enrs on publishing definition to API (#3993)

• core: fix some comment (#3995)

• app: bump version from dev to rc (#3997)

• *: v1.7.0-rc2 (#4003)

• *: v1.7.0-rc3 (#4008)

• *: v1.7.0-rc4 (#4013)

v1.7.0-rc3

v1.7.0-rc3 - 2025-10-01

This is Charon's first Fulu-ready pre-release version. Feedback is welcome and appreciated, please use github issues or discord if you have trouble with this release.

Apart from Fulu readiness, there are two major features in this release, both under feature flags:

Attestation source and target vote consensus. If feature flag chain_split_halt is enabled (--feature-set-enable=chain_split_halt), Charon nodes will verify if the target and source votes (FFG) of the attestation they have fetched matches the one proposed from the leader. If not, Charon will not sign the attestation. If no consensus is reached between the nodes, a new leader is chosen. This is a security feature to ensure that in case of a fork in one of the beacon nodes used by the cluster, the rest do not blindly accept. However, head votes (LMD GHOST) are not checked in order not to block attestation signing when beacon node responds slower or receives block later.

Fetch only attestation data with committee index 0 (--feature-set-enable=fetch_only_commidx_0). In Electra the spec for fetching attestation data was changed, hardcoding the committee_index in the request to 0. However, most validator clients continued asking for the specific committee index, while the beacon nodes disregarded this field and returned the data. On Charon we are forced to do both in order to accommodate both behaviors. Now, most VCs updated their implementations, in this issue we link the version at which the VC implemented the code that allows this feature flag to be turned on. If you enable this feature flag you will reduce the amount of requests Charon sends to the beacon node for attestation data. For big clusters that might be as high as 63 requests less per slot. In big clusters with slower beacon nodes turning on this feature flag improve attestation success rate as well. Confirm in the linked issue that your validator client is new enough to enable this feature. After the Fusaka hardfork, once all VCs request the correct committee index, this feature will be default on.

Read the rest of the release notes for more:

Full Changelog: v1.6.1..v1.7.0-rc3

Feature

• Attestation source and target vote consensus - chain split halt #3876 (#3946)
• Fetcher fetch only attestation data with committee index 0 #3980 (#3989)
• Track SSE events block_gossip and block #3877 (#3938)
• Add publishing new cluster definition to Obol API with only --operator-enrs #3993
• Allow beacon node basic auth in URL #3926

Misc

• Turned on feature flag metric #3979 (#3994)
• Add self identification to logs #3919 (#3939)
• Allow pushing metrics to OTLP insecurely #3983
• Remove the pretty key from JSON logging #3924 (#4005)

Compatibility Matrix

This release of Charon is backwards compatible with Charon v1.0.*, v1.1.*, v1.2.0, v1.3.*, v1.4.*, v1.5.*, v1.6.* Though only v1.3.* and newer are Pectra-ready and none of the previous 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

Validator 👉 Consensus 👇	Teku v25.9.3 ❗	Lighthouse v8.0.0-rc.0	Lodestar v1.35.0-rc.0	Nimbus v25.9.1	Prysm v6.1.0	Vouch 1.12.0-beta.3 ❗
Teku v25.9.3 ❗	✅	✅	✅	✅	✅	🟡
Lighthouse v8.0.0-rc.0	✅	✅	✅	✅	✅	🟡
Lodestar v1.35.0-rc.0	✅	✅	✅	✅	✅	🟡
Nimbus v25.9.1	✅	✅	✅	✅	✅	🟡
Prysm v6.1.0	🟠	✅	✅	✅	✅	🟡
Grandine v2.0.0.rc0	✅	✅	✅	✅	✅	🟡

What's Changed

• app/version: bump to v1.7-dev (#3889)

• cmd: add hostname verification (#3901)

• cmd: renamed add-validators flags (#3902)

• dkg: add zipped flag (#3903)

• core: replace context.WithCancel with t.Context (#3905)

• *: bump go to v1.25 (#3910)

• app: fix some inconsistent function name in comment (#3912)

• *: added otlp headers (#3915)

• p2p: error on closing canceled stream (#3916)

• *: bump govulncheck to v1.1.4 (#3922)

• app: fallback buildinfo logic (#3930)

• *: codebase typos and spelling checked (#3936)

• core/fetcher: improve fee recipient checking (#3937)

• cmd: add missing space (#3957)

• p2p: separate peer and relay p2p metrics (#3971)

• dutydb: check only source and target for commidx 0 (#3974)

• *: otlp insecure flag (#3983)

• *: bump go-eth2-client to v0.27.0-obol.1 (#3985)

• *: bump golangci-lint to v2.5.0 (#3986)

• cmd: cleanup (#3990)

• *: allow --operator-enrs on publishing definition to API (#3993)

• core: fix some comment (#3995)

• app: bump version from dev to rc (#3997)

• *: v1.7.0-rc2 (#4003)

• *: v1.7.0-rc3 (#4008)