This previous week, simply over 100 Ethereum core contributors gathered above the Arctic Circle — in Longyearbyen, Svalbard — for the Soldøgn Interop: per week of intense work on the Glamsterdam community improve.
Soldøgn adopted final 12 months’s Berlinterop, however returned to the format utilized by Amphora 🏺, Edelweiss 🏔️, and Nyota ✨: a single-track week of targeted, multi-client progress towards a particular improve — on this case, hardening Glamsterdam.
By Friday, the group had delivered on its three core targets: alignment on a post-Glamsterdam fuel restrict ground of 200M, secure ePBS implementations operating with exterior builders, and remaining EIP-8037 repricing numbers locked in. Significant progress was additionally made on Hegotá options like FOCIL and native account abstraction, in addition to a slew of different subjects.
Why Svalbard?
Svalbard is among the few locations on Earth the place anybody, no matter nationality, can reside and work and not using a visa. It is also dwelling to the International Seed Vault and the Arctic World Archive, two cold-storage services tunneled into the permafrost outdoors Longyearbyen. Between them they maintain backups of crops, books, movies, manuscripts, and supply code that humanity may want a thousand years from now, together with a snapshot of Ethereum’s supply code. Final however not least, from late April by means of August, the solar does not set in Svalbard. It has 24/7 uptime, similar to Ethereum, which core devs made probably the most of through the week!
Harden Glamsterdam, Scale Ethereum
The week’s objective was to harden Glamsterdam implementations and derive a goal for a post-upgrade fuel restrict ground. Elevating the fuel restrict safely is a multi-dimensional downside and Glamsterdam tackles a number of of them: how blocks are constructed and proposed, how a lot headroom consumer implementations have underneath load, and the way state-creation prices scale alongside throughput.
In apply that meant ending the week with a secure multi-client Glamsterdam devnet operating the newest ePBS, repricing and block entry record specs, together with benchmarking knowledge to anchor a reputable fuel restrict proposal.
More often than not was spent heads down writing code, typically till the early hours of the morning, punctuated by breakout classes to align on design selections and talk about longer-term roadmap objects.
Three EF groups supplied infrastructure for the week: EthPandaOps shipped ethIQ and a panda MCP server to help groups’ agentic workflows; Protocol Assist arrange soldogn.xyz as the only supply of reality for interop targets, schedule, and notes; and the EF Digital Studio staff captured the week on movie. Count on the very first interop documentary 🔜!
ePBS
Past cleansing up the proposer/builder relationship, ePBS restructures slots by including deadlines for block development, payload reveal, and attestations. This makes specific how a lot time may be allotted for execution, growing the top room now we have to boost the fuel restrict.
Groups kicked off the week aiming for a 4 EL × 4 CL Glamsterdam devnet by Monday night. The primary makes an attempt surfaced sufficient points to push the goal to Tuesday, when a 4×3 configuration ran stably sufficient for stress testing to start.
From there, the remainder of the week was an ePBS hardening cycle: stress check, expose edge circumstances, repair, repeat. A Tuesday-morning Builder API breakout considerably simplified the spec round validator registration, the bid/header/commitments circulation, the belief mannequin for builder funds, and circuit-breaker conduct. Mid-week debugging zeroed in on cross-client edge circumstances — notably round execution-request invalidation of beacon requests, the place a brand new check suite revealed a spot throughout each consumer implementation. By Thursday morning, CL groups have been reporting secure ePBS whereas EL-side bid pathways have been nonetheless being debugged; these resolved by means of Thursday into Friday. Two questions stay genuinely contentious for ACD: whether or not a request signature ought to decide to the receiving builder, and tips on how to hold a 1 ETH-staked-builder design resilient in opposition to P2P Sybil-based liveness assaults.
By Friday, almost all purchasers have been operating collectively on glamsterdam-devnet-2 with the exterior builders pipeline examined end-to-end!
BAL Optimizations
If ePBS is the consensus-layer facet of the Glamsterdam scaling story, the execution layer counterpart has two dominant items: fuel repricings and Block-Stage Entry Lists. By giving purchasers sufficient details about a block’s learn/write arrange entrance, BALs allow parallel execution, batched I/O, and parallel state-root computation, all of which decide how massive a block purchasers can comfortably deal with.
The Soldøgn BAL monitor ran by itself devnets, separate from the Glamsterdam ePBS chains, so optimization benchmarks weren’t entangled with consensus-layer stabilization work. Every optimization sat behind its personal characteristic flag so the week’s measurement work may examine them in isolation fairly than as a single bundle. The BAL benchmark dashboard and leaderboard surfaced every consumer’s worst-case eventualities throughout the check suite — by specializing in elevating the slowest paths first, groups may raise the fuel restrict ground throughout the board, not only for the quickest implementation.
Fuel Repricings
Glamsterdam contains quite a few EL fuel repricings, calibrating prices to raised match useful resource utilization at increased throughput. EIP-8037, the state-creation fuel price improve, sits on the core: it raises the value of writing new state so {that a} increased fuel restrict does not translate into unbounded state progress.
Heading into Soldøgn, the 8037 spec carried dynamic per-state-byte pricing tied to the block fuel restrict, which made testing combinatorially painful (one fuzz matrix per fuel restrict band) and benchmarking almost intractable. Groups agreed early within the week to drop dynamic pricing in favor of a hard and fast cost_per_state_byte, with future repricing dealt with at fork boundaries fairly than inside a fork.
The accounting mannequin itself took a extra iterative path. The Monday breakout moved state-gas accounting from mid-execution to end-of-call-frame; a Tuesday follow-up closed out account creation prices, code deposit prices, and CREATE-transaction reverts; Wednesday surfaced reservoir refund/refill edge circumstances that compelled a rethink. The Thursday breakout reverted accounting to opcode degree, having concluded that the actual complexity sat within the reservoir mannequin, not within the accounting computation. By Friday the spec had stabilized on bal-devnet-6, with the BAL monitor delivering the ultimate repricing numbers.
This entire arc highlights one of the crucial vital facets of interop: the power to resolve complicated spec, implementation, testing, debugging, and design points in hours as a substitute of weeks. At their greatest, interop weeks can compress a month of asynchronous progress into every day!
By Friday, the three threads converged on the headline quantity for the week: a reputable 200M post-Glamsterdam fuel restrict ground. This important improve is feasible as a result of ePBS constructions the slot to present execution extra time, BAL optimizations give purchasers the throughput headroom underneath that construction, and 8037 ensures the upper fuel restrict does not translate into runaway state progress.
Different Glamsterdam Threads
Past ePBS, BALs and repricings, a lot of the remaining Glamsterdam scope was hashed out throughout breakout classes.
CL groups finalized selections on smaller Glamsterdam EIPs: EIP-8061 (exit/consolidation churn improve) was included in glamsterdam-devnet-1; EIP-8080 (exits through the consolidation queue) was declined for inclusion; EIP-8045 (slashed-validator obligation removing) was scoped right down to proposer duties inside the look-ahead window solely; and EIP-7688 (SSZ secure containers) stays in Glamsterdam scope however is held out of glamsterdam-devnet-1 whereas the staff works by means of bounded gossip-message dimension for attestations underneath progressive lists.
A Wednesday-morning EL/CL sync structure breakout deferred EIP-8237 out of Glamsterdam in favor of preserving optionality for a longer-term “top-up sync” structure in a future fork. Instead, the room agreed to draft an EIP that normalizes forkchoiceUpdated / newPayload / getPayload sequencing, specifies a snap-sync initiation handshake, and tightens legitimate/invalid consistency between the engine API surfaces.
Hardening was a continuing theme of the week. A Thursday session coated fork-choice compliance testing frameworks, the Diamond repo of reproducible CL edge-case eventualities, and buildoor, PandaOps’s external-builder testing software, demoed mid-session to an extended stream of assault eventualities attendees advised on the spot.
Past Glamsterdam
A number of breakouts appeared towards Hegotá and the forks that comply with.
A intentionally proposal-agnostic session on native Account Abstraction kicked issues off, working by means of the necessities and constraints any future design should fulfill. Function-set targets like various signature schemes, aggregation, batching, restoration, fuel sponsorship, versatile nonces, and keystore wallets sat alongside arduous constraints round public-mempool compatibility, statelessness, and L2 DoS resistance.
A Thursday FOCIL breakout targeted on implementation updates: early prototypes have been already practical, with multi-client interop and a devoted FOCIL devnet because the quick subsequent steps. Two notable design selections have been additionally made: disabling FOCIL throughout 2-epoch non-finality (mirroring proposer-boost circuit-breaker conduct), and adopting an index-based bookmark method for compatibility with body transactions / EIP-7702.
Additional out, a long-running ETH P2P monitor sketched a QUIC-based substitute for libp2p with privacy-by-default and slot-aware integration, alongside an erasure-coded broadcast prototype that simulated ~6× sooner propagation than GossipSub on 2.4 MB payloads. The CL monitor additionally surfaced robust sentiment towards ultimately deprecating consolidations fully — declaring a remaining fork that helps them, then forcing exit-then-redeposit afterwards — because the cleaner long-term reply to validator-set state progress.
ACD Course of
On Wednesday afternoon, Nixo and Ansgar, the 2 ACDE co-leads, ran a session to gather enter from core contributors concerning the ACD course of. The session revisited the headliner assemble, debated the professionals and cons of getting a strawmap, and formalized EIP SFI standards. The room broadly wished to maintain headliners however loosen the EIP-vs-theme rigidity, accepting “theme + candidate EIP” as a viable sample. The straw map’s per-fork 12 months assignments previous 2026 have been flagged as overcanonicalized and prone to be softened. A brand new four-point SFI definition was put ahead, with ACDT signaling readiness and ACDE/ACDC retaining the ultimate name. A brand new prioritization-ordering course of — produced after CFI selections and mirrored within the meta-EIP — will change SFI’s previous position of driving devnet inclusion, beginning with Hegotá.
On the call-coordination facet, Alex Stokes introduced he can be taking a three-month sabbatical beginning subsequent week, with Pari overlaying ACDC moderation within the interim and Barnabas filling in for ACDT. All advised: Nixo and Ansgar chair ACDE, Pari is interim on ACDC, and Mario, Barnabas, and Danceratopz rotate ACDT moderation.
The whole lot Else
Along with all the above, groups used the in-person time to make progress on all the pieces from higher check harnesses (compressing Hive suggestions loops from hours to minutes), to engine-API plumbing enhancements (gossip dedup, batched calls, and light-client-driven head discovery), to arduous tradeoffs round consumer variety, and lots of different subjects. The total record of session notes is offered at soldogn.xyz.
Subsequent Steps
From right here, groups head dwelling to take what was prototyped through the week and make it production-ready. Count on the subsequent a number of weeks to be heads-down on hardening consumer implementations in opposition to the brand new specs, finalizing check protection, and turning Soldøgn’s draft PRs into merged code.
As at all times, the ultimate selections for values such because the 200M fuel restrict goal and remaining repricing numbers can be made and shared publicly on AllCoreDevs calls. Count on these to be the foremost subjects of the subsequent week!
Thanks very a lot to everybody who got here all the best way as much as 78°N and made this week a hit! Particular shout out to EthPandaOps for whipping the group into form every single day, and to everybody who labored underneath the midnight solar to ensure we hit our each day targets — together with the Ethrex crew, becoming a member of us for his or her first interop. It was an extremely productive week, and fortunately we’ll have a full quick movie to recollect it by ☀️
