Agenda
NO CALL ON TUESDAY MARCH 31 — EthCC. NEXT CALL: APRIL 14.
Bi-weekly, Tuesdays @ 12:00 UTC [NEW TIME]
- Facilitator: Will Corcoran (will@ethereum.org · @corcoranwill)
- YouTube
- Previous Call
- Discord
- Spec PR
- Explainer
- Slides
- Prysm Write-up
- Website
Client Implementation Status
| Client | Status | Contact |
|---|---|---|
| Prysm | Old algo impl; 25% on latest spec | Terence |
| Lighthouse | EPF PoC; running test vectors | — |
| Teku | PoC complete; production dev starting | Anton |
| Nimbus | Spec reviewed; active in spec PRs (Etan finding edge cases) | Etan |
| Lodestar | Spec tests passing; running test vectors; deploying to staking env | Nazar |
| Grandine | TBD | — |
Testing
- Format: Extended fork choice tests (Altair+)
- Status:
is_one_confirmedtests merged; previous-epoch block confirmation tests nearing completion. Test vectors published — Lighthouse and Lodestar running them successfully. - Coverage: Targeting ~90-95%
- Paper: Readability improvements in progress; no algorithm changes
- Repo: [consensus-spec-tests TBD]
Call 05 Summary (Mar 17, 2026)
Headline
Spec approaching finalization — three changes landed since Call 04 (refactor, underflow fix, long-standing discrepancy fix), with Etan from Nimbus responsible for catching two of them. Mikhail targeting spec merge in the coming weeks; may happen asynchronously around EthCC. Test vectors published and running on Lighthouse and Lodestar. Website (fastconfirm.it) shipped to positive reception; inbound partner conversations underway. Metrics standardization surfaced as a new workstream. No client devs on the call again.
Client Updates
- No client developers present this call.
- John Church (Nethermind) created a dashboard tracking client FCR implementation status — currently shows Lodestar and Lighthouse as having enabled support.
Spec Changes
| PR | What | Status |
|---|---|---|
| #28 | Adversarial threshold for honest FFG support — last substantial spec change expected before finalization | Merged (test fix landed) |
| Refactor PR | Refactor — introduced underflow found by Etan (unsigned integer subtraction). Fix: return zero as safeguard. | Merged + follow-up fix merged |
| Bug fix | Long-standing spec discrepancy — present since initial spec. Also caught by Etan. | Merged |
Spec finalization target: Next couple of weeks. Mikhail to update test format and fix Gloss test failures that broke due to fork choice function updates. Merge may happen asynchronously given EthCC timing.
Spec relationship to consensus-specs: FCR is standalone but extends the fork choice Store with new variables (e.g., canonical chain head at previous slot start) and modifies the safe block hash passed from CL → EL. Backwards/forwards compatible with hard forks. Closest analog: weak subjectivity period spec.
Testing & Research
- Previous-epoch block confirmation tests in progress; Luca targeting completion by end of week (mid-March).
- Test vectors published; Lighthouse and Lodestar running them successfully.
- Testing does not depend on the research paper — algorithm is at final state.
- Paper: Roberto and Luca improving readability (soft introduction to lemma series). No algorithm changes foreseen.
- Underflow edge case: returning zero is sufficient; dedicated test can be written later.
GTM & Outreach
- Website launched (fastconfirm.it) — positive feedback. Call-to-action intake form generating inbound partner conversations.
- RPC Standards call (Mar 23): Julian to present FCR for awareness. RPC providers don’t need to act yet, but should know about it for when customers ask. Can point downstream customers to the website for security difference explanations.
- Bridge feedback: RPCs could compete on fastest fast-confirmation delivery (more interesting with ePBS as attestations arrive earlier in the block).
- EthCC booklets: Being printed for distribution at Kin. Mikhail, Julian, Will to divvy up on-site.
Metrics Standardization (New)
- Mikhail raised standardizing observability metrics (drawn from Lighthouse implementation) across clients — goal is a common metric set so different clients can be monitored on the same dashboard.
- Not enforced, but a “should implement” standard so that if a client implements metrics, they match.
- Will suggested contacting Katya (experienced with client-agnostic metrics from PQ Interop / Pyridos).
- Key open question: which metrics are most meaningful? Should also factor in what downstream users/partners want to measure.
Action Items
| Owner | Item |
|---|---|
| Mikhail | Finalize spec; update test format; fix Gloss test failures |
| Luca | Complete previous-epoch block confirmation tests; publish updated test vectors |
| Luca + Roberto | Continue paper readability improvements |
| Mikhail | Draft proposed list of standardized FCR metrics; reach out to Katya |
| Julian | Present FCR at RPC Standards call (Mar 23) |
| Julian + Will | Continue partner intake conversations from website leads |
| Will | Coordinate EthCC booklet printing with Digital Studio (Nuno) |
| Will | Continue async outreach to client teams — attendance remains a priority |
| All client devs | Review latest spec changes (refactor, underflow fix, discrepancy fix) |
Agenda for Call 06
A. Client updates (round-robin)
B. Spec status — merged to consensus-specs? Any post-merge issues?
C. Testing — previous-epoch tests complete? Updated test vectors? Coverage assessment
D. Paper status
E. Metrics standardization — proposed metric list? Katya contact made?
F. RPC Standards call debrief (Julian)
G. GTM update — partner conversations, EthCC takeaways
H. Lodestar staking env metrics (Nazar — carried from Call 04)
I. Open discussion
Add agenda items: Comment below with topic
Meeting Time: Tuesday, April 14, 2026 at 12:00 UTC (60 minutes)