FOCIL Breakout #31, March 24, 2026

Protocol Calls & happenings
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Agenda

  • Development updates
  • Spec updates
  • Testing updates
  • and more

Meeting Time: Tuesday, March 24, 2026 at 14:00 UTC (60 minutes)

GitHub Issue

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Meeting Summary:

The team provided updates on backend development progress and Interop implementation, with discussions around timelines and testnet setup requirements. Updates were shared regarding Lodestar container changes and potential API rebasing considerations. The team also discussed execution specs updates, including library rebasing and testing infrastructure improvements, with plans to focus on reference tests and extend testing capabilities after HCC.

Click to expand detailed summary

The team discussed development updates, with Justin reporting that the backend work is progressing well but at low priority, focusing on engine API implementation and building tasks. Justin indicated he couldn’t provide a timeline due to upcoming holiday plans and would need to consult with Fabio for more details. Regarding Interop, Justin expressed confidence that they could have something built ready but noted that clearer answers would depend on setting up testnets and Kurtosis stacks for validation.

Justin confirmed that a four-week timeline for joining DevNet was reasonable. Nico reported no major updates for Lodestar, mentioning only minor container updates needed for the Beacon API. The discussion concluded with a brief exchange about potentially rebasing the API on a different system, though no specific changes were identified as necessary.

Jihoon discussed updates to the execution specs, including rebasing them on top of the Hegota library and proposing a new deadline at 12 seconds into the slot to prevent split views among testers. He also outlined four types of tests for the CL and mentioned ongoing work with the Steel Team to update the testing infrastructure for inclusion lists. The team agreed to focus on reference tests for now and extend testing over time, with plans to make more progress after HCC.

Next Steps:

  • Justin: Consult with Fabio about timeline for builds before going on holiday
  • Justin: Provide clearer answer on Interop readiness once testnets and kurtosis stacks are set up
  • Basis team: Have something built ready for Interop (4 weeks out)
  • nflaig (Lodestar): Review the spec updates when time permits
  • Jihoon: Continue working on the 12-second attester cutoff deadline specification after EthCC
  • Jihoon: Update the EIP after completing the attester cutoff deadline work
  • Jihoon: Update specs from time to time as Amsterdam changes
  • Steel Team: Update testing infrastructure in EL to support inclusion list

Recording Access:

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YouTube recording available: https://youtu.be/eM1LKIUJbEc

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FOCIL stays the course toward Hegotá.

Development Updates

  • Besu has a FOCIL PR under review, covering engine APIs implementation and block building. The team is currently prioritizing Glamsterdam optimizations.

  • Lodestar has no major updates as CL teams are currently busy with ePBS devnet-0.

Spec Updates

  • Jihoon is rebasing all FOCIL specs on top of Hegotá. The EL spec and engine APIs spec have rebased on top of Amsterdam.

  • The CL spec is already on top of Heze but there will be more changes regarding deadlines. Firstly, the 8-second deadline will be removed as it is an implementation-dependent example, which Nico pointed out nearly a year ago. Then, a new 12-second deadline will be introduced for attester’s view freeze. When an IL committee member equivocates, all attesters should share the same view of that equivocation. If some attesters observe the equivocation before their attestation while others only see it afterward, there will be a split view. This issue was found by Mikhail about 9 months ago.

  • The deadline changes are still work in progress and will be revisited after EthCC, followed by an EIP update.

Testing Updates

Links

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