Execution Venues

How to integrate Tycho in different execution venues.

Cow Protocol

To solve orders on CoW Protocol, you'll need to prepare your solution following specific formatting requirements.

First, initialize the encoder:

let swap_encoder_registry = SwapEncoderRegistry::new(Chain::Ethereum)
    .add_default_encoders(None)
    .expect("Failed to get default SwapEncoderRegistry");
    
let encoder = TychoRouterEncoderBuilder::new()
    .chain(Chain::Ethereum)
    .user_transfer_type(UserTransferType::TransferFrom)
    .swap_encoder_registry(swap_encoder_registry)
    .build()
    .expect("Failed to build encoder");

When solving for CoW Protocol, you need to return a Solution object that contains a list of interactions to be executed in sequence.

To solve with the Tycho Router you only need one custom interaction where:

1. callData is the full encoded method calldata using the encoded solution returned from encoder.encode_solutions(...)

2. allowances is a list with one entry where the allowance for the token in and amount in is set for spender to be the Tycho Router. This is necessary for the transferFrom to work.

Uniswap X

To help you fill Uniswap X orders using Tycho, we provide an example UniswapXFiller contract. This contract is a starting point—you should adapt it to fit your use case.

The example contract:

• Inherits from IReactorCallback and implements execute and reactorCallback

• Calls the TychoRouter from reactorCallback to execute swaps

• Uses standard token approvals to allow TychoRouter to pull funds; you can replace this with Permit2 easily (you need to change the encoding accordingly though).

• Approves the UniswapX Reactor contract to transfer tokens out after execution

• Only supports solving one order at a time; you can extend it to support batching by implementing executeBatch and updating reactorCallback

• Can safely hold tokens. The Uniswap X Reactor only transfers out the required amount. If your solution is more efficient, any surplus stays in the filler contract

• Is not audited—use at your own risk

See how to encode the callbackData for TychoRouter here.

How to deploy the Uniswap X Filler

The current script deploys an Uniswap X filler and verifies it in the corresponding blockchain explorer.

Make sure to run unset HISTFILE in your terminal before setting the private key. This will prevent the private key from being stored in the shell history.

1. Set the following environment variables:

export RPC_URL=<chain-rpc-url>
export PRIVATE_KEY=<deploy-wallet-private-key>
export BLOCKCHAIN_EXPLORER_API_KEY=<blockchain-explorer-api-key>

1. Confirm that the variables tychoRouter, uniswapXReactor and nativeToken are correctly set in the script. Make sure that the Uniswap X Reactor address matches the reactor you are targeting.

2. Run npx hardhat run scripts/deploy-uniswap-x-filler.js --network NETWORK.

For more on filling Uniswap X orders, see their docs and examples.

Other competition venues

For other venues, like 1inch Fusion, please contact us.