The whole picture of chain abstraction: classification, hierarchy and complete implementation

Author: Carlos Maximiliano Cano, Ethan Francis, Particle Network; Translation: 0xjs@黄金财经

Introduction

In 2024, the chain abstraction vertical has grown exponentially, and teams across the industry are working towards a common goal: simplifying the experience of Web3 users in a multi-chain, fragmented ecosystem.

Blockchain fragmentation is deeply rooted at the technical, economic, and cultural levels. Therefore, chain abstraction cannot be achieved as a whole through a single universal solution. Even in the early stages of the technology, it became clear that there were multiple standards, approaches, and understandings of chain abstraction, all of which addressed different parts of friction across chains.

This article will expand on our existing classification of chain abstraction methods. Then, the concept of different levels of user experience is introduced to explain how chain abstraction can be more fully implemented from the user's perspective. We will also delve into the pros and cons of each different level and examine how their combination can best be used to create a complete implementation of chain abstraction - completely eliminating the cognitive burden of users using different chains.

Recap: Different Approaches to Chain Abstraction

In our previous exploration of the chain abstraction stack, we categorized all solutions that aim to solve Web3 fragmentation into three approaches:

• Comprehensive Approach:Involves infrastructure that solves multiple chain abstraction challenges simultaneously. These challenges can be cross-chain communication, gas abstraction, liquidity unification, etc. The comprehensive approach is spearheaded by projects such as NEAR, Particle Network, and Polygon’s AggLayer. Projects that take this approach aim for “full implementations of chain abstraction” as we defined in the introduction.

• Application (Orchestration):is the second approach, which enables developers to build applications that orchestrate the execution and management of operations on different chains with a single user-level signature. One such application might allow users to perform transactions in one chain using assets from another chain, with all underlying bridge transactions automatically handled. Agoric, Skip, and Socket are some of the innovative projects in this category. Projects that take this approach typically aim to create application-level implementations of chain abstraction.

• Single Problem Chain Abstraction Solutions: is the third and final approach that focuses on solving a single fine-grained problem related to chain abstraction. These solutions provide primitives that are critical for building cross-chain infrastructure and can even serve as underlying components for the above two approaches. One such problem explored by protocols such as LayerZero and Hyperlane is cross-chain messaging, which allows orchestration and comprehensive solutions to run across blockchains.

Different Chain Abstraction Approaches

Next, we will explore the different ways that synthesis and orchestration solutions achieve their goals, and the different levels of chain abstraction experience they create (from the user's perspective). We will also dive into the relationship between the different levels, and how the different levels can interoperate and find synergies. To do this, we will use the above integration depth spectrum as a blueprint to segment and organize the different user-facing chain abstraction levels, which is influenced by another popular framework for understanding chain abstraction: CAKE.

Let’s quickly review the CAKE framework as it will provide useful context to introduce the multi-layer model.

CAKE Framework: Layering Chain Abstraction

The CAKE framework, developed by Frontier Research, proposes a systematic approach to organizing and unifying chain abstraction solutions. It consists of three main layers: the permission layer, the solver layer, and the settlement layer.

The application layer contains different applications built on the chain abstraction stack. The permission layer refers to the technologies of the account and execution layer, such as account abstraction, intent, and key management solutions. The solver layer can then facilitate the deconstruction of intents and the execution of cross-chain logic and other related functions. Finally, the settlement layer includes the DA layer, bridges, oracles, and other underlying technologies. Each layer in the framework contributes to the chain abstraction, allowing the collective presentation of a complete implementation.

CAKE framework for chain abstraction

Combining the CAKE framework with different approaches to implementing chain abstraction, we can create a mental framework to categorize the user experience of different solutions and their relationship to each other.

Different levels of chain abstraction

There are three different types of user flows for chain abstraction solutions:

1. Blockchain-level chain abstraction.The farthest from developers and end users in the stack. This level typically involves a network or collection of chains that agree to share security, cross-chain messaging/bridging, and other properties that enable them to easily migrate, or in some cases share state between blockchains. Examples include Polygon's AggLayer and the Cosmos ecosystem, which supports IBC to some extent.

2. Account-level chain abstraction. Chain abstraction applied at the account level provides a common, low-lift mechanism for unified state (account settings, balances, etc.) for user accounts across chains. Account-level chain abstraction is specifically targeted at end users and is inspired by account abstraction.

3. Application-level chain abstraction. Enabling cross-chain shared account state purely through account-level or blockchain-level chain abstraction (sometimes both) does not solve the problems of application developers. This level of chain abstraction provides developers with the flexibility to achieve seamless cross-chain transactions and intent execution directly through a single signature of their dApp.

Now let’s take a closer look at the different levels covered above and what they mean.

Blockchain-Level Chain Abstraction (Comprehensive)

Blockchain-level chain abstraction implements chain abstraction as the basis for the experience of the chain itself. It is therefore the most comprehensive level from both a technical and user perspective.

This type of chain abstraction involves the aggregation of various opt-in blockchains that share properties such as security, bridges, etc. (e.g., Polygon’s AggLayer or the IBC-enabled Cosmos blockchain). The implementation of this approach greatly facilitates higher parts of the stack, such as account-based chain abstraction, as it provides security guarantees as well as efficient cross-chain messaging that is not possible to the same extent between separate blockchains. This makes this approach well suited for chains within the same ecosystem, enabling them to have a unified bridging solution and security guarantees. An example of blockchain-level chain abstraction is Polygon’s AggLayer, which aggregates zk-proofs from a set of chains and submits them to Ethereum for settlement. However, one of the main challenges of chain abstraction is the lack of unified communication and bridging standards between chains under different ecosystems, often due to differences in architecture, economics, and security. Although other ecosystems may lag behind, protocols such as IBC in the Cosmos ecosystem have already achieved this unified communication. Blockchain-level chain abstraction aims to unify ecosystems and address this lack of peer-to-peer, although it is unlikely to be adopted by several major ecosystems (such as Solana and Ethereum) under the same solution for the reasons mentioned above. Blockchain-level chain abstraction is not a requirement to achieve the ideal of chain abstraction, although as mentioned above, it helps a lot with user experience, especially when combined with account-level chain abstraction. The following figure shows the interaction of various chains in blockchain-level chain abstraction.

Blockchain-level chain abstraction design

Account-level chain abstraction (comprehensive)

While blockchain-level chain abstraction solves the problem of lack of peer-to-peer infrastructure between blockchains and lays the foundation for complete chain abstraction, account-level solutions solve the fragmentation problem at the user level.

These solutions directly provide users with a universal cross-chain seamless interaction mechanism, providing various methods to achieve shared account status and transfer assets throughout the ecosystem. Many implementations of account-level chain abstraction, such as Particle Network's universal account, aim to create an experience where the underlying blockchain on which a given application is built becomes an infrastructure detail that is irrelevant to users, as their balances and addresses remain unchanged across all users.

Applications must choose to use account-based chain abstractions, but they often offer little to no programming lift. These solutions tend to handle cross-chain movement and coordination separately, impacting only the end-users interacting with a given application, not the application itself.

Both account-based and blockchain-based chain abstractions can be viewed as “comprehensive” solutions that address important parts of chain abstraction, and can work well alone or in tandem with each other. However, as mentioned earlier, the full implementation of chain abstraction can be approximated by a combination of comprehensive and intermediate solutions. This is where application-level chain abstraction comes in.

Application-Level Chain Abstraction

Finally, there is an application-level approach that is closest to developers - application chain abstraction (Orchestration). Even with the presence of the other two layers of chain abstraction, individual applications need a way to meaningfully leverage this abstraction to realize its full potential. Orchestration addresses this gap by enabling developers to build applications that seamlessly (and often without the user's knowledge) span multiple chains and ecosystems. In practice, this aims to execute asynchronous, long-running business logic across various chains to maximize the composability of on-chain components. Projects such as Agoric, Skip, and Socket focus on application chain abstraction.

An example of an application-level chain abstraction tool is Agoric’s Orchestration API, which provides developers with contracts and APIs to execute cross-chain transaction flows with a single signature from the end user. This allows for complex cross-chain workflows and operations without adding any complexity and abstracts the process of interacting with different blockchains into a simplified set of calls, simplifying the developer experience.

Application chain abstraction can also be implemented in conjunction with account-level chain abstraction, allowing developers to simplify the benefits of these solutions to create a complete implementation of chain abstraction.

Design of Application Chain Abstraction Solutions

Relationships between different layers

The complete implementation of chain abstraction requires a way for multi-layered solutions to work together to completely eliminate friction between multiple chains. This will inevitably lead to modular relationships between the layers.  

These relationships can be further understood through the collaboration of account-level and application-level chain abstractions. Using the solutions introduced above as examples, you can see how developers can use Particle Network and Agoric's solutions together to maximize the capabilities that users get from both tools.

The following diagram shows how these solutions work together to achieve a complete implementation of chain abstraction:

Multi-layer chain abstraction approach, including application-level and account-level chain abstraction

It should be pointed out that in this setting, blockchain-level chain abstraction becomes an optional but crucial solution that needs to be implemented whenever possible. Blockchain-level chain abstraction exists to reduce friction at the account level and application level, and the friction that they cannot solve directly can be solved by a unified blockchain, which is an alternative that can only help the rest of the higher-level projects achieve a seamless interoperable ecosystem.

A Real-World Example of Layered Chain Abstraction: Agoric + Particle Network

As mentioned above, account-level chain abstractions and application-level solutions can work closely together to abstract user interactions and transactions across multiple blockchains, enhancing the overall Web3 experience.

Let’s now examine how solutions can be built using Particle Network’s Universal Accounts and the Agoric API and their potential use cases. This will combine the following factors:

• Particle Network’s Universal Accounts, acting as the primary interface and interaction point for end users. Users can create and access these accounts simply by connecting an existing wallet, which enables them to perform transactions using balances from any chain. With Universal Accounts, the underlying chain of an application is agnostic to the user interacting with it.

• Agoric’s Orchestration API makes it easy for developers to program seamless multi-chain transaction sequences at the application level by providing simple API calls to manage on-chain instructions. This includes determining which contracts to interact with, which messages to send, and any intermediate steps required to manage that action.

By using both application-level and account-level solutions, users can focus on their goals rather than the technical details of blockchain operations, while developers can focus on building specific flows that serve users rather than dealing with the nuances of cross-chain interactions.  

This composite solution can be used for a variety of use cases, including:

Multi-chain Asset Managers

Multi-chain asset managers can simplify how users interact with their assets on multiple blockchains, similar to using centralized platforms such as exchanges. The right combination of account-based chain abstractions and application chain abstractions can recreate the seamless experience of an exchange entirely on-chain. From a user’s perspective, they are able to perform complex multi-chain trade flows, swaps, and interact with smart contracts hosted on any blockchain without having to understand the underlying multi-chain interactions; instead, they will see a simple, Web2-like interface for performing multifaceted on-chain operations.

Login with IBC

A single sign-on and authentication model tailored for the Inter-Blockchain Communication Protocol (IBC) ecosystem, covering both application chains and off-chain services. Inspired by Ethereum Improvement Proposal 4361 and Chain-Agnostic Improvement Proposal 122, such a solution would simplify the onboarding process for IBC-connected applications or protocols, providing a unified account-based UI and user-friendly interaction points while remaining secure and decentralized.

This would allow users to use their universal account to log in once and access multiple applications in the IBC ecosystem without having to re-authenticate due to the application chain abstraction. Extending this concept, session management logic could be implemented to keep users logged in even when moving between applications on different IBC-enabled blockchains. 

DeFi Aggregators

It would also be possible to build an aggregator with minimal operational complexity, allowing users to focus on maximizing returns rather than complex logistical execution. This approach would enhance the user experience by providing a single point of control over different assets and DeFi strategies, and remove technical barriers that prevent newbies from using DeFi. To fully leverage both levels of chain abstraction, the product could also have built-in complex trading strategies spanning multiple chains.

For example, through a DeFi aggregator, a user can initiate a swap on a given chain and deploy the received assets into a pool on another chain. The following image illustrates this (albeit in a different context):

Cross-chain flow of liquidity, recently proposed by Agoric

Multi-chain governance platform

A multi-chain governance platform can provide a secure and transparent system for voting and staking tokens across multiple blockchains. It will ensure strong on-chain authentication to verify user identity and make it easier to participate in on-chain and off-chain voting. Combining Particle’s universal accounts for seamless asset and identity management with Agoric’s Orchestration API for efficient cross-chain operations, developers can design a friendly interface to easily manage functions such as participation, displaying votes, viewing proposals, or tracking governance token balances.

Full Implementation of Chain Abstraction

As detailed in this article, chain abstraction is a goal that requires collaboration and synergy between multiple approaches and even different levels within the same approach. The classification model presented here and the examples of applications produced by combining tools such as Particle’s universal accounts and Agoric’s Orchestration API illustrate the tangible benefits provided by chain abstraction.

The above exploration most importantly highlights the evolution of Web3 towards creating a more unified and user-friendly environment, as well as the diversity of strategies that can be used to improve the cross-chain user experience. Each abstraction layer not only serves its unique function, but also complements other layers to form a comprehensive ecosystem where user interactions are simplified and the underlying complexity of blockchain interoperability is abstracted away.

I hope this article will help you better understand chain abstraction, its panorama, classification, layers, and complete implementation.