Swapper is Astrolab's liquidity meta-aggregator, powering all of its monochain and cross-chain swaps. It blends liquidity and bridge aggregators. The DEX meta-aggregation was inspired by LlamaSwap's work available here, supercharged with cross-chain capacity.
Astrolab DAO and its core team members will not be held accountable for losses related to the deployment and use of this repository's codebase. As per the licence states, the code is provided as-is and is under active development. The codebase, documentation, and other aspects of the project may be subject to changes and improvements over time.
Don't hesitate to reach out or submit pull requests with missing aggregators adapters.
- Li.Fi
stabletested - Squid Router
stabletested - Socket
stabletested
The Swapper SDK facilitates TransactionRequests and raw CallData construction for every aggregator, in a unified way.
The querying uses a generic ISwapperParams object as seen here.
The SDK can be used off-chain via ethers or viem, the generated callData can be used with any provider implementation or directly on-chain by passing the callData to the Swapper.sol contract on the desired chain.
import { AggregatorId, ISwapperParams } from "@astrolab/swapper/types";
import { getCallData, getTransactionRequest, swapperParamsToString } from "@astrolab/swapper";
import { TransactionRequest } from "ethers";
const _1inchSwap: ISwapperParams = {
aggregatorId: AggregatorId.ONE_INCH,
inputChainId: 250, // fantom->fantom
input: addresses[250].tokens.LZUSDC,
output: addresses[250].tokens.AXLUSDC,
amountWei: 100 * 1e6, // $100
payer: `0xPaYeR`
};
const lifiSwap: ISwapperParams = {
aggregatorId: AggregatorId.LIFI,
inputChainId: 250, // from fantom
input: addresses[250].tokens.LZUSDC, // USDC-e
outputChainId: 10 // to optimism
output: addresses[42161].tokens.LZUSDC, // USDC-e
amountWei: 100 * 1e6, // $100
payer: `0xPaYeR`
};
// fetch the transaction request object from both aggregators
// NB: this transaction request object can then be used with ethers.sendTransaction
// eg. ethers.sendTransaction(tr)
async function getTransactionRequests(): TransactionRequest[] {
return await Promise.all([_1inchSwap, lifiSwap]
.map(s => getTransactionRequest(s)));
}
// fetch only the callData from both aggregators
// NB: this callData should be passed to the smart contract .call() directly
// this assumes that the caller already knows the aggregator contract (available in tr.to)
async function getTransactionRequests(): TransactionRequest[] {
return await Promise.all([_1inchSwap, lifiSwap]
.map(s => getCallData(s)));
}The Swapper contract is a proxy that allows generic callData to be executed on the requested aggregator's contract, available from transactionRequest.to.
It adds a layer of security between the client who swap and the target aggregation router.
A Swapper instance can:
- whitelist callers
- whitelist input tokens
- whitelist output tokens
- whitelist router
It also enforces slippage/price impact protection, making the use of external callData inherently safer.
To start using Swapper, you can clone the repository and install the necessary dependencies.
git clone https://github.com/AstrolabFinance/swapper
cd swapperyarn installThis only tests the client functions (typescript SDK).
yarn test-unitThis tests the client functions (typescript SDK) + the contract execution by forking with hardhat and deploying Swapper.sol locally, then passing callData to it.
yarn test-integrationCleans hardhat and typescript compilation caches, artifacts and dist folders.
yarn cleanContributions are welcome! Feel free to open an issue or create a pull request if you have any improvements or suggestions.