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How can I find get approve tx data and check for allowance?

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Checking Allowance & Getting Approve TX Data

Using the SDK:

Use getTokenAllowance to check current allowance:

import { getTokenAllowance } from '@lifi/sdk';

const allowance = await getTokenAllowance(token, ownerAddress, spenderAddress);
 

Use setTokenAllowance to approve tokens:

import { setTokenAllowance } from '@lifi/sdk';

const txHash = await setTokenAllowance({
  walletClient,
  token: { address: tokenAddress, chainId },
  spenderAddress: approvalAddress, // from quote.estimate.approvalAddress
  amount: fromAmount,
});
 

Using the API directly:

The approvalAddress is returned in the quote response under estimate.approvalAddress. You'll need to call the ERC20 approve and allowance functions directly on the token contract using this address as the spender.

The End-to-end Transaction Example page (mentioned below) shows a complete checkAndSetAllowance function using ethers.js.

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