Swapping

​

Summary

​

Fetch the Price

The Price is a lightweight quote, excluding steps and calldata but it includes a preview of what the full quote might contain. Prices are subject to change once you get the quote so you should handle price changes accordingly. Once you determine where to swap from and to, the amount and the currency then you can pass everything into the getPrice or the usePrice hook depending on if you’re using the sdk or the ui hooks:

​

Fetch the Quote

If you followed the previous step, you can pass that same data into the getQuote action or useQuote hook.

In the above example, we fetch the quote to swap 0.1 ETH on Ethereum Mainnet to USDC on Base. In the quote object we’ll get data on the fees required to do this swap. You can learn more about fees here.

Note - Quotes can go stale after 30 seconds. Clients should regularly fetch fresh quotes so that users are always submitting valid transactions. Learn more about Relay quotes.

​

Execute the Quote

After getting the quote all that’s left is to execute the quote and render the progress to the user. Follow the code snippets below to execute the quote:

While the quote is being executed if you’re rendering the quote in an interface you may want to display progress to the user. There’s a provided progress callback to get the updated state of execution. Learn more about the progress state here.

​

Preflight Checklist

☐ Verify that the user has enough balance on the origin chain to cover the full swap amount + fees. Check out our fees doc for more details on calculating the fees.
☐ Have the Relay SDK set up and the Relay hooks package installed if applicable
☐ Ensure the user is on the correct chain (it should match the chainId you get the quote from)
☐ Handle any errors that may come about
☐ Render the progress of the swap to provide a best in class user experience