Written by: imToken
In the previous article of the Interop series, we introduced the Open Intents Framework (OIF), which acts like a universal language, allowing users to express intentions such as “I want to buy an NFT cross-chain,” and have solvers across the network understand them (Read more: “When ‘Intent’ Becomes the Standard: How OIF Ends Cross-Chain Fragmentation and Brings Web3 Back to User Intuition”).
But simply “understanding” isn’t enough; it also needs to “get done.” After all, once your intent is sent out, how does your fund securely move from Base to Arbitrum? How does the target chain verify your signature is valid? Who pays for the gas on the target chain?
This involves the core of the “Acceleration” phase in Ethereum’s interoperability roadmap—the Ethereum Interoperability Layer (EIL). At the recent Devconnect, the EF Account Abstraction Team officially brought EIL to center stage.
In short, EIL’s goal is highly ambitious: without hard forks or changes to Ethereum’s underlying consensus, it aims to make all L2s feel like they’re being used on the same chain.
- What Exactly Is EIL?
To understand EIL, don’t be misled by the word “Layer”—EIL is not a new blockchain, nor is it a traditional cross-chain bridge.
Essentially, it is a set of standards and frameworks that combine “account abstraction (ERC-4337)” and “cross-chain messaging” capabilities to build a virtual unified execution environment.
In the current Ethereum ecosystem, each L2 is an isolated island. For example, your account (EOA) on Optimism and your account on Arbitrum may have the same address, but their states are completely separate:
A signature on chain A cannot be directly verified on chain B.
Assets on chain A are invisible to chain B.
EIL attempts to break this isolation through two core components:
Smart accounts based on ERC-4337: Utilizing the power of account abstraction to decouple account logic from keys; using the Paymaster mechanism to solve the issue of having no gas on the target chain; leveraging Key Manager to achieve multi-chain state synchronization.
Minimized trust messaging layer: Establishing a standard that allows UserOps (user operation objects) to be packaged and securely transmitted to another chain via the official rollup bridge or light client proofs.
To use an analogy: traditional cross-chain is like traveling abroad—you need to exchange currency (cross-chain assets), get a visa (re-authorize), and follow local traffic rules (buy gas on the target chain). In the EIL era, cross-chain is more like using a Visa card:
No matter which country you’re in, just swipe your card (sign once), and the underlying banking network (EIL) will automatically handle exchange rates, settlement, and verification. You don’t feel the existence of borders.
The EIL solution proposed by the Ethereum Foundation’s account abstraction team envisions this future: users complete cross-chain transactions with a single signature, without relying on centralized relays or new trust assumptions, and can initiate transactions directly from their wallet and settle seamlessly across different L2s.
This actually comes closer to the ultimate form of “account abstraction.” Compared to today’s high-threshold, fragmented operations, this experience will help users automatically create accounts, manage private keys, and handle complex cross-chain transactions.
Especially with native account abstraction (AA), all accounts become smart accounts, allowing users to ignore gas fees (or not even know gas exists) and truly focus on on-chain experience and asset management.
- Paradigm Shift: From “Cross-Chain” to “Chain Abstraction”
If EIL is truly implemented, it could bridge the “last mile” for Web3 mass adoption. This marks Ethereum’s ecosystem moving from multi-chain competition to chain abstraction integration, potentially solving some of the most painful problems for users and developers.
First for users, it enables a true “single-chain experience.”
Simply put, under the EIL framework, users no longer need to manually switch networks. For example, all your funds are on Base, but you want to play a game on Arbitrum. You just click start in the game, your wallet pops up a signature box, you sign, and the game begins.
Behind the scenes, EIL automatically packages your UserOp on Base, sends it via the messaging layer to Arbitrum, and the Paymaster covers your gas and entry fee. For you, it’s as smooth as playing the game directly on Base.
From a security perspective, it also eliminates the single point of failure of multi-signature bridges.
Traditional cross-chain bridges usually rely on a set of external validators (multi-sig). If hackers compromise this group, billions of dollars in assets are at risk. EIL emphasizes “trust minimization,” preferring to use the inherent security of L2s (such as storage proofs) to verify cross-chain messages rather than relying on third-party trust. This means as long as the Ethereum mainnet is secure, cross-chain interactions are relatively safe.
Finally, for developers, it provides a unified account standard. Today, a DApp aiming for multi-chain support requires developers to maintain multiple sets of logic. With EIL, developers can assume users have a unified cross-chain account and only need to write interfaces for the ERC-4337 standard, naturally supporting users across all chains, without worrying about where their funds are.
However, to realize this vision, we still face a huge engineering challenge: How can hundreds of millions of existing EOA users enjoy this experience? (Read more: “From EOA to Account Abstraction: Is Web3’s Next Leap Happening in the ‘Account System’?”)
After all, migrating from EOA to AA requires users to move assets to a new address, which is too much hassle. This leads to Vitalik Buterin’s recently proposed EIP-7702, which cleverly resolves the compatibility debates among three previous proposals (EIP-4337, EIP-3074, EIP-5003) by doing something magical: allowing existing EOA accounts to “temporarily transform” into smart contract accounts during a transaction.
This proposal means you don’t need to register a new wallet or move assets from your current imToken (or other wallet) address to a new AA account. Instead, with EIP-7702, your old account can temporarily gain smart contract features (such as batch authorization, sponsored gas, atomic cross-chain operations), and after the transaction, it reverts to its highly compatible EOA state.
- EIL Implementation and the Future
Compared to the more community-driven “bottom-up” approach of OIF, EIL has a stronger official character, driven primarily by the EF Account Abstraction Team (the creators of ERC-4337).
Specifically, current progress is mainly focused on three key areas:
Multi-chain extension of ERC-4337: The community is researching how to extend the ERC-4337 UserOp structure to include target chain IDs and other cross-chain information, which is the first step toward giving smart accounts “clairvoyance.”
Collaboration with ERC-7702: With EIP-7702 (which gives EOA smart account capabilities) moving forward, ordinary EOA users will soon be able to seamlessly access the EIL network, greatly lowering the user barrier.
Standardized messaging interfaces: Like OIF’s intent standardization mentioned in the previous article, EIL is pushing for standardized messaging at the infrastructure layer. Optimism’s Superchain, Polygon’s AggLayer, and ZKsync’s Elastic Chain are all exploring interoperability within their ecosystems, while EIL aims to connect these heterogeneous ecosystems and build a universal messaging layer for the entire network.
Even more interesting, EIL’s vision doesn’t stop at “connecting”—it’s also adding another critical foundational capability: privacy.
If EIP-7702 and AA solve “accessibility,” then the Kohaku privacy framework announced by Vitalik at Devconnect may become the next piece in EIL’s puzzle, echoing another core idea from the “Trustless Manifesto”: “censorship resistance.”
At Devconnect, Vitalik stated bluntly, “Privacy is freedom,” and said Ethereum is on a privacy upgrade path, aiming to provide real-world privacy and security. To this end, the Ethereum Foundation has established a privacy team of 47 researchers, engineers, and cryptographers, dedicated to making privacy a “first-class property” of Ethereum.
This means privacy will no longer be an optional add-on, but as natural a core feature as transferring funds. To realize this vision, the Kohaku framework was developed—essentially, Kohaku uses your public key to create a temporary stealth address, allowing you to perform private actions without revealing links to your main wallet.
With this design, future AA accounts will not just be asset management tools, but privacy shields.
By integrating protocols like Railgun and Privacy Pools, AA accounts will allow users to protect transaction privacy while compliantly providing “proof of innocence,” enabling anyone to prove their funds are not from illegal sources without exposing their spending paths.
At this point, we can clearly see the full picture of Ethereum’s interoperability roadmap:
OIF (Intents Framework): Allows the application layer to “understand” user needs;
EIL (Interoperability Layer): Paves the way for execution at the infrastructure layer.
This may also be the clear message the Ethereum Foundation wants to send: Ethereum should not be a loose collection of L2s, but a vast, unified supercomputer.
In the future, when EIL is truly implemented, we may no longer need to explain to new users what L2s or cross-chain bridges are. At that point, all you’ll see are your assets, with no barriers between chains.
