YakSwap

Dex aggregator for EVM chains. UI available here.

About

YakSwap is a set of smart contracts for optimal path finding between two assets and execution of that path. For input&output token and input-amount optimal path should have a greatest net amount-out by considering execution gas-cost.

Search is performed by calling on-chain query-methods and can be called by anyone. However, user should avoid calling query-methods in a mutative call due to a very large gas-cost associated with a call.

Usage

Router

YakRouter is the user-facing interface to check prices and make trades.

Chain	Address
Avalanche	0xC4729E56b831d74bBc18797e0e17A295fA77488c
Base	0x50564bF9cE3b1eA33c7bDb5acfFb1B997C319aE4
Arbitrum	0xb32C79a25291265eF240Eb32E9faBbc6DcEE3cE3
Optimism	0xCd887F78c77b36B0b541E77AfD6F91C0253182A2

Base also has a SimpleRouter deployment at 0xD7A465165338B0B53dfDdef2Ee07cd8870Cd7dc7.

findBestPathWithGas

Finds the best path from tokenA to tokenB. Considers path's amount-out and its gas-cost.

function findBestPathWithGas(
    uint256 _amountIn,
    address _tokenIn,
    address _tokenOut,
    uint256 _maxSteps,
    uint256 _gasPrice
) external view returns (FormattedOffer memory);

Input params	Details
amountIn	Amount of tokens being sold
tokenIn	ERC20 token being sold
tokenOut	ERC20 token being bought
steps	Max number of steps for path finding (must be less than 4)
gasPrice	Gas price in gwei that will be used to estimate gasCost of each step

struct FormattedOffer {
    uint256[] amounts;
    address[] adapters;
    address[] path;
    uint256 gasEstimate;
}

Return arg	Details
amounts	Amount of token being swapped for each step. First amount is _amountIn and last amountOut.
adapters	Addresses of adapters through which trade goes.
path	Addresses of tokens through which trade goes. First token is _tokenIn and last _tokenOut.
gasEstimate	Rough estimate for gas-cost of all swaps. Gas estimates only include gas-cost of swapping and querying on adapter and not intermediate logic, nor tx-gas-cost.

swapNoSplit

Executes trades through provided path.

function swapNoSplit(
    Trade calldata _trade,
    address _to,
    uint256 _fee
) external;

Input param	Details
_trade	Arguments used for swapping
_to	Reciever address
_fee	Optional fee in bps taken before the trades

struct Trade {
    uint256 amountIn;
    uint256 amountOut;
    address[] path;
    address[] adapters;
}

Param	Details
amountIn	Amount of tokens being sold
amountOut	Amount of tokens being bought
path	Tokens being traded in respective order
adapters	Adapters through which tokens will be traded in respective order

Adapter

Adapters act as a common interface for YakRouter to interact with external contracts.

Adapters offers methods: query and swap.

function query(
    uint256 _amountIn,
    address _tokenIn,
    address _tokenOut
) external view returns (uint256);

function swap(
    uint256 _amountIn,
    uint256 _amountOut,
    address _fromToken,
    address _toToken,
    address _to
) external;

See deployments/ for known router, adapter, hop-token, and Uniswap V4 pool configuration by chain. To inspect a live router, use the Foundry script:

forge script script/admin/ListAdapters.s.sol --rpc-url <network>

Examples:

forge script script/admin/ListAdapters.s.sol --rpc-url base
forge script script/admin/ListAdapters.s.sol --rpc-url avalanche

Local Development and testing

This repository uses Foundry for compilation, testing, scripts, and deployment. Solidity package dependencies are managed with Foundry's native Soldeer integration and the checked-in soldeer.lock file.

Install Foundry

curl -L https://foundry.paradigm.xyz | bash
foundryup

Make sure the Foundry binaries are available on your PATH:

forge --version
cast --version
anvil --version

Install Dependencies

Clone submodules and install Soldeer dependencies:

git submodule update --init --recursive
forge soldeer update

Set Environmental Variables

Copy the sample env file and fill in any private keys, RPC URLs, or explorer API keys needed for your workflow:

cp .env.sample .env

At minimum, fork tests and scripts need RPC endpoints for the networks you target. Public RPC examples:

export BASE_RPC="https://mainnet.base.org"
export AVALANCHE_RPC="https://api.avax.network/ext/bc/C/rpc"

foundry.toml currently defines RPC aliases for:

• base
• avalanche
• arbitrum
• optimism
• mantle

Build

forge build

Test

Run all tests:

forge test

Run Base tests:

forge test --match-path 'test/base/*.sol' --rpc-url base

Run Avalanche tests:

forge test --match-path 'test/avalanche/*.sol' --rpc-url avalanche

Run a single test file:

forge test --match-path test/base/Aerodrome.t.sol --rpc-url base

Deploy

Deployment scripts live in script/deploy/. Run without --broadcast first to simulate, then add --broadcast to submit transactions.

Example simulation:

forge script script/deploy/base/DeploySimpleRouter.s.sol:DeploySimpleRouter --rpc-url base

Example broadcast:

forge script script/deploy/base/DeploySimpleRouter.s.sol:DeploySimpleRouter \
  --account deployer \
  --rpc-url base \
  --broadcast \
  --verify \
  --etherscan-api-key "$ETHERSCAN_API_KEY"

Admin scripts

Admin scripts live in script/admin/. They are generally written to support a dry-run/check mode without --broadcast and an execute mode with --broadcast.

Examples:

forge script script/admin/ListAdapters.s.sol --rpc-url base
forge script script/admin/UpdateAdapters.s.sol --account deployer --rpc-url base
forge script script/admin/UpdateAdapters.s.sol --account deployer --rpc-url base --broadcast

Adding adapters

See docs/adding-new-adapter.md for adapter requirements and implementation notes. New adapters should usually include:

• the adapter contract under src/adapters/
• interface additions under src/interface/, if needed
• deployment constants in deployments/
• a deployment script under script/deploy/<network>/
• fork tests under test/<network>/

Misc

• Static-Quoters used in KyberElastic, UniswapV3 and Quickswap adapters are published here.

Audits and Security

This project is not audited. Use at your own risk. For any questions or bug reports reach out via Telegram group YakDevs or its admins.

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Project is licensed under GPL-3, although some parts of it might be less restrictive. Copyright© 2021 Yield Yak