Switchlane

Smart Contract Diagram
Switchlane Info

Inspiration

The current state of bridges, wallets, and blockchains is frustrating. It requires you to have tokens and wallets on every chain you wish to transact on. Switchlane is building a crosschain future enabling transactions from any chain to any chain without needing to own the native blockchain token to pay for gas.

What it does

Using account abstraction, liquidity pools and CCIP, users can transfer their assets gas free and across chains.

How we built it

Using Alchemy's account abstraction infrastructure we were able to create a smart wallet for each EOA that connects to Switchlane. The EOA is set as the signer for the smart wallet transactions. It's set up that way to simplify the process for people that haven't interacted with smart wallets before. The transaction is then sent to a paymaster to sponsor the gas fee and a bundler posts the transaction onto the blockchain.

Our smart contract uses Chainlink data feeds, if needed, to make sure that the swaps in Uniswap are fair. Once the smart contract has confirmed the needed tokens it sends and pays the transaction cost in LINK (CCIP), it connects to the CCIP router in its chain and sends the tokens to the receiver in the chain that was requested.

Challenges we ran into

The most complex process was planning the architecture of the project around our ideas. In the beginning we had the idea to abstract the gas fee from an EOA transaction. This led us to EIP2117 and then to EIP4337. This was a lengthy process, learning how paymasters and bundlers work to provide gasless transactions.

In the smart contract we required a way to pay the CCIP fee so that the users tokens could be transferred crosschain. This problem was solved by integrating a liquidity pool and token swap, swapping out a part of the tokens for CCIP-BnM to pay the fee on testnet and the rest being sent through the crosschain protocol.

Additionally, developing a simple, reliable and stable user interface was a challenge we conquered. Setting up chain switching with the smart wallet was difficult as the provider had to be reset with a different rpc url, api key and gas policy for each chain.

Accomplishments that we're proud of

Now users can use Switchlane to send one token and receive the same or another on another chain. Doing this through CCIP is secure and unlike other bridges it allows Switchlane to build complex systems on top. Switchlanes modular design is something we are truly proud of. It will allow future development to be fast and strong while paying for gas with the token the user is sending. This adds a much-needed abstraction layer for new and non-technical users, which is key to the mass adoption of blockchain technologies.

We take pride in the team we've built, and none of us has ever experienced such effortless collaboration with people from around the world before.

What we learned

The future of blockchain technology is crosschain and account abstraction. Reducing barriers to entry for the general public and moving assets around without friction is a necessity. CCIP provides the simplicity and security required to transfer assets across chains safely. Account abstraction creates opportunities like removing the native token gas fee and social logins.