SDK
All any-to-any protocols in one SDK
A small blazing fast wrapper over the Via Router API for on-chain and cross-chain swaps. Our API allows you to find the best route for moving funds between chains!
feature | remark | method |
|---|---|---|
get routes | Swaps/bridges cheapest routes | getRoutes |
check allowance | Allowance to check whether it's needed or not to approve | getAllowanceStatus |
build approval transaction | The transaction that approves the VIA contract to spend your token | buildApprovalTx |
build transaction | The transaction that will perform a swap/bridge according to the route | buildTx |
check transaction | Check the status of the transaction | checkTx |
npm i @viaprotocol/router-sdk
First you need to initialize a VIA Client instance:
import {Via} from '@viaprotocol/router-sdk';
const DEFAULT_API_KEY = 'e3db93a3-ae1c-41e5-8229-b8c1ecef5583';
const cli = new Via({apiKey: DEFAULT_API_KEY, url: 'https://router-api.via.exchange', timeout: 30000});
Get the best routes.
const pagesNum = await cli.routesPages(); // cache me!
const baseParams = {
fromChainId: 1,
fromTokenAddress: '0x0000000000000000000000000000000000000000',
fromAmount: Math.pow(10, 18),
toChainId: 56,
toTokenAddress: '0x0000000000000000000000000000000000000000',
fromAddress: '0x856cc59aaE47997a1C8D5472Fc8dfef27821235d', // might be null
multiTx: false, // whether to return routes with multiple user transactions
limit: 1,
};
const params = [...Array(pagesNum)].map(
(_, i) => ({
...baseParams,
offset: i+1
})
);
const routes = await Promise.allSettled(
params.map(i => cli.getRoutes(i))
);
Request parameters description
Parameter | Description |
|---|---|
fromChainId | Source chain id |
fromTokenAddress | Source token address |
fromAmount | Amount |
toChainId | Target chain id |
toTokenAddress | Target token address |
fromAddress | Sender address |
multiTx | whether to return routes with multiple user transactions |
offset | Pagination offset |
limit | Pagination limit |
Pagination is needed because the request time for a specific page is faster than for all pages at once
Get allowance status
You must approve the contract to spend your token. You can get route_id from the route you like received above in the code snippet.
const firstNonEmptyPage = routes.find(i => i.value.routes.length > 0).value;
const route = firstNonEmptyPage.routes[0];
const routeId = route.routeId;
const chainId = fromChainId;
const owner = "YOUR_WALLET_ADDRESS";
const tokenAddress = fromTokenAddress;
const numAction = 0; // number of action in routes
const allowanceStatus = await cli.getAllowanceStatus(
{owner, routeId, numAction}
);
Build approval transaction. Returns the transaction that approves the Via API to spend your token.
const amount = fromAmount;
tx = await cli.buildApprovalTx(
{routeId, owner, numAction}
)
Now you can build the transaction that will perform a crosschain swap according to the route.
# amount out minimal, you can get it from get_routes as to_token_amount
output = firstNonEmptyPage.routes[0].toTokenAmount
tx = await cli.buildTx(
{
routeId,
fromAddress,
receiveAddress,
numAction
}
)
If you want to know the status of the transaction, then you need to tell us that you started it
await cli.startRoute(
{
fromAddress: fromAddress,
toAddress: receiveAddress,
routeId: route.routeId,
txHash: txHash
}
)
And start action (you can start from the second action because startRoute also handles first action)
await cli.startAction(
{
actionUuid: route.actions[numAction].uuid,
initialTxHash: actionTxHash
}
)
You can see the status of the transaction.
const txStatus = await cli.checkTx(
{
actionUuid: route.actions[numAction].uuid
}
)
You can use websocket
const v = new Via({apiKey: DEFAULT_API_KEY});
const wsProvider = v.getRoutesViaWs({
fromAddress: '0xD75183E452d6915356814454D2D64Df149853D38',
fromAmount: 148875000000000000,
fromChainId: 56,
toChainId: 56,
fromTokenAddress: '0x0000000000000000000000000000000000000000',
toTokenAddress: '0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d',
multiTx: true
});
wsProvider.onopen = function open() {
console.log('connected');
};
wsProvider.onclose = function close() {
console.log('disconnected');
};
wsProvider.onmessage = function incoming(data) {
const res = JSON.parse(data.data as string);
let route: IRoute[];
let status: IRouteFetchStatus;
if (Array.isArray(res)) {
route = res;
console.log(route);
} else {
status = res.status;
console.log(status);
if (status.finished === status.all){
wsProvider.close()
}
}
};
Response parameters description
Parameter | Description |
|---|---|
retry | Time to retry in ms |
event | Status of the transaction |
data.started | Started time of the transaction on source chain |
data.finished | Finished time of the transaction on source chain |
data.txHash | Hash of the destination transaction |
data.actualAmount | Received amount |
With via.exchange it is possible to execute routes in several steps. This will help expand the number of available routes and, as a result, help you find the most profitable routes!
const pagesNum = await cli.routesPages(); // cache me!
const baseParams = {
fromChainId: 1,
fromTokenAddress: '0x0000000000000000000000000000000000000000',
fromAmount: Math.pow(10, 18),
toChainId: 56,
toTokenAddress: '0x0000000000000000000000000000000000000000',
fromAddress: '0x856cc59aaE47997a1C8D5472Fc8dfef27821235d', // might be null
multiTx: true, // !!
limit: 1,
};
const params = [...Array(pagesNum)].map(
(_, i) => ({
...baseParams,
offset: i+1
})
);
const routes = await Promise.allSettled(
params.map(i => cli.getRoutes(i))
);
Now all you need is to sequentially execute transactions for different numAction
const actionCount = firstNonEmptyPage.routes[0].length;
for (let numAction = 0; i < specified_len; i++) {
tx = await cli.buildTx(
{
routeId,
fromAddress,
receiveAddress,
numAction
}
);
}
Multichain and Hyphen bridges don't support transfers from non-whitelist accounts. Therefore, it is necessary to filter routes with these bridges for users with multi0signature wallets.
Last modified 1yr ago