BOB Gateway: Connecting Bitcoin through Intents

tl;dr:

  1. Bitcoin intents simplify interacting with Bitcoin: anyone can stake BTC, swap BTC to ERC20 tokens, or end arbitrary messages to smart contracts with a single Bitcoin transaction.
  2. BOB has deployed Gateway, an implementation for Bitcoin intents that has served over 21,000 users with 50,000 staking and swapping requests.
  3. Users are staking BTC into Babylon via SolvBTC, uniBTC, Pell, supplying wBTC into Segment lending markets, and swapping BTC for wBTC and tBTC.
  4. Any app on BOB can integrate Gateway to onboard users directly from Bitcoin.

Bitcoin, despite its $1.66T+ market cap, remains largely isolated from the innovative DeFi ecosystem. While Ordinals, Runes, and BRC20s have started a Renaissance of builders and users alike, most BTC still remain idle, unable to participate in yield-generating activities or more complex financial operations. In our opinion, one of the key blockers remains the complex bridging procedures that require users and builders to utilize various wallets, apps, and intermediaries to move BTC. This post introduces a dramatic simplification: Bitcoin intents.

Intent-based bridging has become popular in the Ethereum space as the rise of countless L2s requires a new form of interaction that should remain abstract of the underlying chain(s). While intent-based bridging is available on EVM and other chains with Turing-complete smart contracts, intents have eluded the Bitcoin space thus far.

We’re proposing Bitcoin intents as a two-way solution to allow users, DAOs, builders, and anyone else to seamlessly interoperate between Bitcoin and BOB. BOB is a hybrid L2 that combines Bitcoin's security with Ethereum's programmability, serving as an ideal platform for intent-based bridging.

Bitcoin Intents in a Nutshell

Bitcoin intents differ from intents in the EVM space. Until BitVM is ready, settlement needs to happen on the EVM chain: In ERC7683 and related proposals, both the source and the destination chain can be used for settlement. For Bitcoin intents, settlement on Bitcoin itself is not yet possible. Rather, settlement always requires a two-phase commit protocol:

  1. Locking tokens (e.g., wBTC, tBTC, USDT, …) in a smart contract on the EVM chain.
  2. Sending a transaction on Bitcoin, e.g., send BTC to an address or mint an ordinal to an address.
  3. Unlocking the tokens from the smart contract (and possibly executing several smart contract steps after the unlock) by submitting a SPV proof to a Bitcoin light client on the EVM chain that confirms the correct execution of the Bitcoin transaction with sufficient confirmations.

The goals for Bitcoin intents are:

  • Efficiency: By specifying the intent upfront, the network can optimize the bridging process, by finding the best solvers to serve the user in an open network.
  • Flexibility: Users can execute complex operations across chains in a single Bitcoin or BOB transaction.
  • Improved User Experience: The complexity of cross-chain operations is abstracted away, presenting a seamless interface to the user.
  • Liquidity Activation: Enables idle Bitcoin to participate in DeFi, potentially increasing overall market liquidity.
  • Ecosystem Growth: Facilitates the expansion of Bitcoin's utility beyond a store of value, fostering innovation in the broader crypto space.

From Bitcoin to BOB: Unleashing Bitcoin's Potential

Picture Alice, a Bitcoin holder yearning to put her BTC to work in DeFi. Today, she can do just that, thanks to the magic of Bitcoin intents. Here's how her journey unfolds:

  1. Alice decides she wants to stake her BTC in a Bitcoin staking protocol that mints an LST on BOB. She crafts her intent as a signed order to a relayer, specifying the exact amounts she wishes to contribute to the Bitcoin staking protocol.
  2. This intent is broadcast to a network of relayers that collect bids from solvers ready to fulfill Alice’s intent.
  3. Behind the scenes, solvers compete to fill the order. The winning solver providing the liquidity locks the tokens into a smart contract and provides their own BTC address to the relay network.
  4. Alice sends her BTC to the solver’s BTC address within a time limit. Encoded within is a commitment to the Bitcoin LST reserved for Alice. If Alice doesn’t send the BTC within a time-limit, the order reverts.
  5. As the Bitcoin blockchain confirms Alice's transaction, the relayer network utilizes the Bitcoin light client to verify the transaction. Alice's intent materializes and she now owns a Bitcoin LST without having to send more than a single transaction or worry about gas tokens.

But this is just the beginning. Imagine DAOs that span both Bitcoin and BOB, where a simple Runes transfer on Bitcoin could encode a vote on BOB. Anyone able to send BTC to smart accounts that can be claimed with an email address or social account. Or taking a stablecoin loan that is then automatically swapped to fiat and sent to a bank account. All within a single Bitcoin transaction.

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From BOB to Bitcoin: A Bridge to New Horizons

Now, let's flip the script. BobcatDAO, an NFT protocol on BOB, wants to mint ordinals on Bitcoin to their favorite members. Here's how Bitcoin intents makes this possible:

  1. BobcatDAO formulates their intent – not just to transfer value, but to create something unique on Bitcoin: Inscribe ordinals to a set of Bitcoin addresses. BobcatDAO locks the necessary funds on BOB – perhaps in wBTC, or maybe in USDC. Any asset available on Ethereum or BOB can be used. BobcatDAO can leverage the DEXes on BOB to ensure the solver gets paid in their preferred currency.
  2. This intent is broadcast to the network of relayers and solvers. The solvers are competing to inscribe the ordinals in return for the funds locked on BOB.
  3. The winning solver, armed with BobcatDAO’s intent, works their magic on Bitcoin. They mint the ordinal through submitting the commit and reveal taproot transactions, inscribing Bobcat’s creativity onto the Bitcoin blockchain.
  4. As Bitcoin confirms the transaction reveal transaction, the relayer network proves their work to BOB's Bitcoin light client, claiming the well-earned reward for the solvers.

But why stop there? Imagine opening LN channels on Bitcoin, DAOs on BOB etching Runes on Bitcoin, or facilitating payments in BRC20 tokens. The line between chains blurs, opening up a new realm of possibilities.

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BOB Gateway as a Home for Bitcoin Intents

Bitcoin intents are a concept that allows cheap, fast, and flexible bridging. BOB Gateway is the reference implementation for Bitcoin intents on BOB. BOB offers unique advantages to facilitate Bitcoin intents. As BOB is an L2, transaction fees are cheap to keep the Bitcoin light client up to date. Further, the majority of assets on BOB are Bitcoin variants. This allows liquidity to be readily available for turning into staked Bitcoin.

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BOB has validated Gateway with more than 21,000 users on-ramping to BOB. Initially, Gateway launched with the capability to swap BTC for Ethereum’s wBTC and tBTC on BOB. Gateway now also supports direct staking of BTC into Solv, uniBTC, and Pell, as well as entering lending markets. Any DeFi protocol deployed on BOB can be added to Gateway to allow direct onboarding with a single BTC transaction. Any app on BOB can integrate Gateway into its frontend to onboard users with a single BTC transaction.

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Moreover, Gateway allows users to easily top up ETH gas for further transactions on BOB.

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You can try BOB Gateway today and become part of the BOB ecosystem:

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Further developments of Gateway will focus on:

  • Optimizations: Reduce costs and transaction time for users through onboarding more solvers/LPs as well as reducing confirmation times for low-value transactions.
  • DeFi use cases: Allow arbitrary swaps and lending integrations to enable use cases such as taking out stablecoin loans or stableswaps.
  • Offramping: Enable users to use BOB Gateway to bridge back to BTC easily.

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Conclusion: The Future is Intentional and Bitcoin

Bitcoin intents isn't just a technical solution – it's a paradigm shift. It reimagines Bitcoin not as a static store of value, but as an active participant in the ever-evolving blockchain ecosystem.

As we continue to refine and expand this technology, we invite you – developers, researchers, and dreamers – to join us on this journey. Together, we're not just building bridges; we're crafting the future of finance, one intent at a time. If you are interested in joining BOB Gateway, reach out to us.

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