Calling

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Summary

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Contract Compatibility

Before we begin it’s important to ensure that a contract is compatible with Relay. Please review our Contract Compatibility overview to make any necessary changes.

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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. You’ll need to determine where the user wants to call the contract from, where the contract has been deployed to, and their preferred payment currency. Afterwards, you can pass everything into the getPrice SDK action or the usePrice UI hook. Note that for calling a contract across chains you’ll need to provide three key pieces of information in addition to the usual data required to call:

• tradeType must be EXACT_OUTPUT.
• txs can either be an array of to, data and value or it can be the response from viem’s simulateContract method. You can see an example below of how this is done.
• amount must be the sum of all the txs values.

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Fetch the Quote

If you followed the previous step, you can pass that same data into the getQuote SDK action or useQuote UI hook. You’ll still need to meet the requirements for tradeType, amount and txs, refer to the previous step for more details.

In the above example, we fetch the quote to call a Zora contract from Mainnet Ethereum. In the quote object, we’ll get data on the fees required to do this call. You can learn more about fees here. You’ll see that we provided an amount that matches the sum of the txs, that the tradeType is EXACT_OUTPUT and that we passed in a valid txs array.

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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.

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Preflight Checklist

☐ Verify that the user has enough balance on the origin chain to cover the full txs 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 execution to provide a best in class user experience