Chain Abstraction for Bitcoin L2s: How BTC Connect Enables Hyperconnectivity

Chain Abstraction for Bitcoin L2s: How BTC Connect Enables Hyperconnectivity

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A few months ago, we released BTC Connect, the first account abstraction (AA) protocol for the Bitcoin ecosystem. 

This release was motivated by two goals: Furthering the interconnection of the Bitcoin and EVM networks, and enabling a natural way for Bitcoin users to onboard into L2s without relying on non-Bitcoin products, such as MetaMask wallets.

Since its release, BTC Connect has been adopted by the leading players within Bitcoin’s booming L2 ecosystem (such as Merlin Chain, B², and SatoshiVM), embracing BTC Connect as the key infrastructure driving native Bitcoin users to adopt their L2. This article will explore how these chains benefit from this integration, and give you a glimpse of BTC Connect’s role in the larger goal of enabling chain abstraction across all corners of Web3.

Context: What is BTC Connect, and why should Bitcoin L2s integrate it?

BTC Connect deepens the interconnectivity of the Bitcoin and EVM ecosystems by enabling users to control ERC-4337 smart accounts (i.e. smart contract wallets) on Bitcoin L2s with their native Bitcoin wallets (e.g. UniSat). This allows developers to tap into the UX benefits of AA within their Bitcoin applications, as well as seamlessly onboard native Bitcoin users.

Thanks to BTC Connect, interactions with products deployed on L2s can be conducted via L1 signatures, without interacting with non-Bitcoin products, as shown below:

BTC Connect’s user flow.

BTC Connect arrives at a critical time for today’s rapidly developing BTC L2 landscape. With most L2s barely starting to develop their own ecosystems, BTC Connect sets the stage for developers building in these chains to embrace and experiment with ERC-4337 AA. Builders can now leverage the security and ubiquity of Bitcoin’s infrastructure while accessing the advanced capabilities of Smart Accounts. 

This dual advantage, presented in an accessible user flow, can accelerate the adoption of L2 solutions, offering enhanced functionalities to users and cultivating a more unified Bitcoin ecosystem.

BTC Connect as a catalyst for chain abstraction

Furthermore, BTC Connect is a vital component of Particle Network’s goal to enable chain abstraction through its Modular L1. This L1 acts as a settlement layer for the multi-chain ecosystem, providing users with a unified address, account, and balance to interact with every chain. As a part of Particle Network’s L1 rollout, the millions of Smart Accounts associated with BTC Connect (as well as Particle Network’s Modular Smart WaaS, which secures $2B worth of asses from 17M users) will be automatically upgraded to Universal Accounts.

Universal Accounts introduce a new UserOperation structure that is processed by Particle Network’s Decentralized Bundlers and relayed to be settled across chains, creating the experience of chain abstraction by automatically facilitating bridging and swapping. As such, BTC Connect is both the first working version of chain abstraction encompassing heterogeneous and EVM chains and an adoption driver for this new paradigm. For more information on the L1’s design, go to our official announcement.

Users of Particle Network’s existing products will be seamlessly onboarded into our modular L1.

Integration case study: Merlin Chain

As mentioned, BTC Connect has been integrated by the leading solutions within the BTC L2 ecosystem. Our documentation provides a full breakdown of all networks which have integrated it. To exemplify a successful integration, we can analyze Merlin Chain’s design.

Merlin Chain, a highly scalable ZK-rollup on Bitcoin, understood the value of using BTC Connect to fulfill its purpose of onboarding Bitcoin users towards its L2 ecosystem. To seamlessly onboard native Bitcoin users and create a streamlined environment for them, Merlin integrated BTC Connect from Day 1, also building it into its two core products:

  • The Merlin bridge.
  • The Merlin Seal airdrop portal, which allows users to deposit assets and mint M-Tokens, which are 1:1 representations of their collateral within the chain.

Furthermore, BTC Connected is also integrated by MerlinSwap, the chain’s native DEX, developed by its community.

Thanks to this, Bitcoin users are able to follow a natural path from holding BTC or assets such as $ORDI in their native wallets to using the L2 with these same assets. For the user, this path distills to the following:

BTC Connect user flow (on Merlin Chain).

Merlin Chain’s BTC Connect integration, as such, results in a natural flow that takes users from holding assets on a Bitcoin wallet to using that same wallet to manage their interactions on the L2. This creates a natural experience and flow for users of the previously siloed Bitcoin L1. 

Furthermore, as users onboarding into L2s experience new products within the Bitcoin ecosystem and Particle Network’s L1 opens the gate for Web3-wide chain abstraction, this will spark increasing network effects and help unify both its ecosystem and economy.

Leveraging BTC Connect as a developer + parting thoughts

Developers can seamlessly integrate BTC Connect within their dApps on over nine Bitcoin Layer-2s, bringing end-to-end ERC-4337 Account Abstraction and native Bitcoin compatibility to their applications in under 100 lines of code, ushering in new possibilities for their use cases. If you’re interested in doing so, we recommend you visit our dedicated SDK page. Currently, BTC Connect is in its first alpha release, so only Web applications are supported. At the bottom of our resources page you’ll also find dedicated tutorials on how to use BTC Connect within different L2s, such as Merlin Chain, B² Network, SatoshiVM, etc.

Furthermore, if you represent a Bitcoin L2, you can always reach out to us using the widgets below to discuss deploying BTC Connect on your chain.

We look forward to bringing chain abstraction to your BTC dApps!


Particle Network's Modular Smart Wallet-as-a-Service solutions are 100% free for developers and teams. If you have any inquiries about integrating with us, feel free to book a meeting with one of our agents!


About Particle Network

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Particle Network is a Layer-1 blockchain built with the Cosmos SDK, equipped with a high-performance EVM execution environment. It serves as chain abstraction infrastructure for the multi-chain ecosystem, featuring Universal Accounts, Universal Gas, and Universal Liquidity. Through these core functionalities, Particle Network addresses the fragmentation of users and liquidity caused by a growing number of blockchains, coordinating operations across networks and empowering all other chains with enhanced interoperability.

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About the author(s)

Carlos Maximiliano Cano

Carlos Maximiliano Cano

Particle's Content Manager. He's been in Web3 since 2017, collaborating with technical and marketing teams in crowdfunding, research, DeFi, privacy, and zero-knowledge proofs.