ACDC #161 is Live! 🗓️ July 24, 2025 at 14:00 UTC On the agenda: 🔹 Fusaka devnet-2 recap & devnet-3 launch 🔹 Target: Release Candidates by end of August 🔹 Glamsterdam: headliner, slot time, ePBS 🔹 SSZ spec discussions 📺 Watch: 🔴 Live/X: #Ethereum #ACDC161 #Fusaka #Glamsterdam

Fusaka Devnet-2: Nearly complete 🔄 @BarnabasBusa: @lodestar_eth & @ethnimbus showing issues in test scenarios 🚀 Devnet-3: Genesis took place ~24h ago, devnet will be forked soon, expect progress on ACDT 🔧 Interop mostly smooth (minor ethconfig issues), MEV infra coming soon 📦 Includes spec changes @ralexstokes: Assuming devnet-3 stability, aim to start hardening & have release candidates by end of August 🎯 Goal: Fusaka mainnet before Devconnect (Nov) 📍Conclusion: Monitor devnet-3 progress → discuss next steps in upcoming ACD call #Ethereum #Fusaka #ACDC161

Glamsterdam Discussion 🧩 Headliner: Agreed to select 1 EIP per layer ⏱️ Shorter Slot Time: In-depth analysis 👩‍💻Maria presented updated data: - Metrics tracked via Xatu, using a @prylabs fork (from @ethPandaOps) - Monitoring block #propagation, #attestation arrival times, and #missed slots - Attestation delays observed — 95th percentile data shows some risk under shorter slots Next steps: Collect more samples, analyze #gas usage impact, and expand community data

🗣️ Lively discussion followed on Shorter Slot Time 📣 @EthDreamer highlighted: - PTC (Parallel Time Construction) enables 4s attestation propagation + aggregation, overlapping with block/blob execution - Potential to optimize slot usage with proper coordination @potuz_eth : - Raised doubts about using p95 as a threshold - Mentioned @preston_vanloon has a working PoC, though incomplete - Points out that attestation timing concentration doesn’t necessarily invalidate the shorter slot time proposal. @dankrad clarifies that the current use of p95 metrics is observational — not prescriptive — and that Ethereum is not attempting to optimize slot times strictly based on p95. @nero_eth points out that parallel time construction (PTC) introduces extra latency due to BLS verification steps — something that should be factored in when considering slot time reductions. @Parithosh: - Confirmed Prysm fork no longer adds artificial delay - Community-collected data will be more representative 📦 @barnabemonnot : - Clarified that 4.4s metric is not meant to “support” or “reject” the 6s proposal — just early data - Clarifying that current data (4413ms) is not sufficient to argue for or against 6s slot times and reflects existing network conditions. 📌 Conclusion: - 6s slot time — still under investigation - More data to be gathered and reviewed - Community participation (e.g. via @ethPandaOps) encouraged #Glamsterdam #shorterslot

Flashbots on ePBS & the “Free Option Problem” – A MEV Perspective (#Glamsterdam) Christopher presented risks in #ePBS related to economic exploits and propagation delay, discussed problems and solutions. Summary: ePBS introduces two deadlines via PTC: ⏱️ Payload: 4s 🫧 Blob: 10s This staggered timing introduces a “free option” — the ability to invalidate a block after submission but before full propagation completes. 🔗 Full writeup: 📌 Summary Takeaways: ePBS adds flexibility, but introduces new risks with longer propagation windows Solo builders/searchers may exploit “free options” Pipelining may neutralize ePBS benefits if we compress timelines again Propagation improvements & design tradeoffs must be reconsidered before finalizing #Ethereum #ePBS #Glamsterdam

More on Glamsterdam Headliner Update @dapplion: ePBS (trustless payments) shouldn’t be forced into slot restructuring — let’s treat them as separate features: • EIP-7732A = slot restructuring • EIP-7732B = ePBS on top 📝 Blog: #Ethereum #Glamsterdam #ePBS 💬 @TimBeiko: There are 3 possible CL headliners — ePBS, 6s slots, or FOCIL, should be kept in CFI. But we should do only one in Glamsterdam. @ralexstokes agrees. 📌 Current status: → ePBS was marked CFI (Considered for Inclusion) — meaning it’s being actively discussed as a serious candidate, but not finalized yet. → Final headliner decision expected at next ACDC call in 2 weeks. 🗳️ Feedback from @LidoFinance , Flashbots, @QuickNode, and others here:

📐 SSZ Spec Update – ACDC #161 Etan from @ethnimbus shared an overview of proposed changes to the SSZ spec 🔧 PR: 🗣️ @ralexstokes: “Not much contention — should be resolved directly on the PR.” ACDC Call concluded early, see you next time! #Ethereum #ACDC161 #SSZ #ConsensusSpecs