Glamsterdam Devnet-2 Advances as Devs Finalizes CFI Scope

Ethereum core developers made meaningful progress on the Glamsterdam upgrade during All Core Devs Testing (ACDT) Call #66, finalizing its CFI scope, advancing execution layer devnets, & clarifying the roadmap for ePBS & MEV-Boost discussions.

The meeting, facilitated by Parithosh, focused on stabilizing Devnet-2, reviewing execution layer EIPs already in scope, & resolving lingering inclusion debates that could impact Glamsterdam’s final composition.

• BALs Devnet-1 Stabilizes
• BALs Devnet-2 Scope Locked
• ePBS Testing Progress
• EIP-8037 Decision & CFI Finalization
• MEV-Boost Integration Discussion

BALs Devnet-1 Stabilizes

Developers confirmed that BALs Devnet-1 has reached a stable state after resolving sync issues across most clients. The devnet has been running reliably with EVM fuzzing in place, while parallel IO & execution testing were intentionally excluded from this phase.

With the environment now considered stable, benchmarking responsibilities have been formally shifted to Devnet-2, marking a clear handoff to the next stage of the testing process.

BALs Devnet-2 Scope Locked

The scope for BALs Devnet-2 is now clearly defined & limited to proposals considered mature enough for near-term testing. Included items:

• EIP-7843
• EIP-7778
• Pre-refund gas accounting alignment
• Receipt updates introducing a second field (already spec’d)
• EIP-7708 (PRs actively merging)
• EIP-8024 included without recent changes

Open design discussions tied to these proposals have been deferred to ACD & Devnet-3. PRs are expected to merge quickly, with Devnet-2 targeting rollout this week, although some clients may join slightly later.

ACDT#66 (Summary)👇
1/@parithosh_j facilitated the meeting
🟨Glamsterdam Devnets
🔹BALs Devnet 1 (Stefan)
- Sync issues fixed across most clients
- Stable runs with EVM fuzzing
- Parallel IO / execution not covered
➡️ benchmarking moved to BALs Devnet 2

🔹BALs Devnet 2 Scope… https://t.co/0F9UXIAaba

— Pooja Ranjan | ranjan.eth (@poojaranjan19) January 19, 2026

ePBS Testing Progress

Work on enshrined Proposer-Builder Separation (ePBS) continues to advance, with teams increasingly focused on preparing the system for coordinated testing. Specifications have now been frozen for test vectors, and block processing implementations are nearing completion across multiple clients, clearing the way for testing to begin in the near term.

However, overall client readiness remains uneven, as several implementations are still missing critical components such as block production logic, gossip validation, and storage handling, highlighting the need for further alignment before broader devnet participation.

EIP-8037 Decision & CFI Finalization

One of the most consequential outcomes of ACDT #66 was the resolution of the EIP-8037 debate. After extended discussion on whether to simplify or delay the proposal, developer sentiment leaned toward shipping the current design, contingent on the availability of adequate tooling support.

While there was some caution expressed around dynamic pricing and gas coordination, participants generally preferred to retain the existing architecture, with broad agreement that any necessary refinements could be addressed after inclusion. With this decision, Glamsterdam’s CFI is now finalized, even as breakout calls continue to refine the remaining technical details.

MEV-Boost Integration Discussion

Developers revisited the long-running proposal to absorb MEV-Boost directly into consensus clients, ultimately reaffirming the existing architectural approach. Client teams broadly agreed that while direct builder connectivity will be supported, MEV-Boost functionality itself will remain external to clients, preserving the current Builder API to MEV-Boost model.

Rather than pursuing deeper integration, the focus will shift toward standardizing the Builder API and improving operator experience through more consistent client flags, such as minimum bid parameters. Further discussion on these improvements is expected to continue in upcoming ACD calls.

With Devnet-2 progressing, the CFI finalized, & higher-risk changes deferred, Glamsterdam’s trajectory now clearly emphasizes containment, safety, & execution readiness. The coming weeks will determine whether client convergence & ePBS testing can advance quickly enough to preserve the upgrade timeline without reopening settled scope decisions.

If you find any issues in this blog or notice any missing information, please feel free to reach out at yash@etherworld.co for clarifications or updates.

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