# FOCIL Prioritization [EIP-7805: FOCIL](https://eips.ethereum.org/EIPS/eip-7805) guarantees fast inclusion of transactions. This is achieved by moving the decision of which transactions to include in a block from a single block builder to a wide set of attesters. FOCIL can be thought of as a mempool attestation gadget, ensuring that a block builder cannot arbitrarily deviate from the global view of existing transactions. At a high level FOCIL democratizes transaction inclusion by moving the decision from a single actor to a decentralized set of attesters. This document does not argue about the merits of FOCIL itself and assumes as given that FOCIL ought to be shipped. It focuses on considerations of *when* to include it on mainnet. With headliners locked in and implementations well underway, ACD is shifting its focus to choosing non-headliner EIPs to include in Glamsterdam. There are good reasons to include FOCIL in Glamsterdam and also good reasons to postpone its inclusion until later forks, e.g. H*-fork. Jumping ahead briefly, the main tradeoff is between cumulative complexity and Glamsterdam delays on the one side, and the tail-risk of FOCIL never shipping on the other. The following is an exercise to steelman both sides. ## The for & against of FOCIL in Glamsterdam There are several key dimensions to reason about when deciding *when* to include FOCIL: **(1) Shipping environment, (2) Hardfork timelines**, (3) Hardfork complexity, and (4) Short-term value of FOCIL. *Please note that at this moment in time FOCIL is the best mechanism available to achieve guaranteed fast tx inclusion. This can change over time. And so some arguments are less about the FOCIL mechanism specifically and should rather be interpreted as arguments for any mechanism able to guarantee fast tx inclusion.* ### "Shipping environment" ##### For FOCIL in Glamsterdam * The ability to ship FOCIL (or some other fast tx inclusion guarantee mechanism) hinges on a favorable environment. As Ethereum goes more mainstream the set of stakeholders is more and more removed from the core crypto community's original values, putting at risk the ability to ship an ideological feature such as FOCIL. There exists the tail risk that the financial, political, regulatory, or governance environment for shipping changes between Glamsterdam and H*. * Defaults are sticky: Establishing FOCIL as the norm now sets a high bar for changing that default in the future. ##### Against FOCIL in Glamsterdam * It is very unlikely that the environment will meaningfully change until the H*-fork. Thus, there is no need to rush FOCIL into Glamsterdam on top of what's already a big hardfork. ### Hardfork timelines *(Apologies for now flipping Against/For order, I know it's triggering* 😅, *but against argument sets up nicely the for argument.)* ##### Against FOCIL in Glamsterdam * Since ePBS is likely to be the main bottleneck to ship Glamsterdam (most involved feature) adding yet another EIP *on the CL side* would necessarily delay Glamsterdam further. This would push Glamsterdam into late 2026 when the ambition was mid 2026. * There is desire and momentum to ship hardforks at a higher cadence, e.g. aiming for a hardfork (optimistically) every 6 months. Fork discipline is important and a good forcing function to ship only must-haves. ##### For FOCIL in Glamsterdam * Guaranteeing FOCIL lands on Ethereum is worth delaying Glamsterdam. The delay has been estimated to be around ~2 months with FOCIL's development quite far already ([devnets with 4CLs and 2ELs](https://x.com/jih2nn/status/1979103547955290235)). * The off-chance that FOCIL (or some other tx inclusion guarantee mechanism) might never land on Ethereum is not worth the risk. It is very unlikely but tx inclusion guarantees are a core value of Ethereum and it should not be put at risk for an estimated hardfork delay of 2 months. The worst case of including FOCIL in Glamsterdam is that it will delay the fork, and break the momentum around fork discipline. But the worst case of not shipping FOCIL now, while momentum and environment is favorable, puts at risk a core value of Ethereum indefinitely. * Sidenote: Once ePBS and BALs are fully implemented and run on devnets, repricing EIPs need to rerun their benchmarking and analysis for the final pricing of resources to fully utilize scaling gains of the headliner EIPs also. This would take some time on the EL, meaning that FOCIL might delay the fork less. ### Complexity ##### Against FOCIL in Glamsterdam * FOCIL changes in parts overlap with ePBS' changes. Importantly they both touch the fork-choice, which has historically been Ethereum's most fragile part of the consensus protocol. It would be more secure to roll out these changes sequentially to allow for better testing. ##### For FOCIL in Glamsterdam * Yes, both ePBS and FOCIL touch the fork-choice and it would be preferable to ship sequentially from a testing standpoint. However, FOCIL complexity is fairly limited, it mostly adds a validity condition to the fork-choice. ### Utility ##### Against FOCIL in Glamsterdam * On Ethereum today transaction inclusion is [very high](https://censorship.pics/), so shipping FOCIL today would *not* give users any tangible benefits. ##### For FOCIL in Glamsterdam * FOCIL arguably necessary for [shortening withdrawal window for stage 1 optimistic rollups](https://x.com/rudolf6_/status/1986176728440709311). * More improtantly: Just because transaction inclusion is high today does not guarantee it will remain so tomorrow. FOCIL is not urgent until it is. It is important for Ethereum to *guarantee* fast transaction inclusion. Without FOCIL (or some other tx inclusion guarantee mechanism) this core value of Ethereum is not guaranteed. ## Conclusion The core tradeoff is between added complexity and potential Glamsterdam delays on one side, and the risk of FOCIL (or some other tx inclusion guarantee mechanism) never shipping on the other. In the end, the question comes down to one’s read on how likely the “shipping environment” is to shift between Glamsterdam and later hardforks — or put simply, whether that risk is low enough to prioritize fork discipline now. Different assessments will land at different conclusions: Ship FOCIL in Glamsterdam, in H*, or later.