0x API – Understanding Swap Destination Address

By using the token address in sellToken or buyToken fields. E.g for ETH->SHIB, https://api.0x.org/swap/v1/quote?sellToken=ETH&sellAmount=1000000000000000&buyToken=0x95ad61b0a150d79219dcf64e1e6cc01f0b64c4ce or https://api.0x.org/swap/v1/quote?sellToken=0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee&sellAmount=1000000000000000&buyToken=0x95ad61b0a150d79219dcf64e1e6cc01f0b64c4ce.

The above has always worked but we added a "convenience" layer to specify the symbol. It became a source of confusion as this token list was always a subset of tokens that 0xAPI could find swaps for.

After some thorough research, I have come to an answer myself. The 0x swap calldata does not hold the amount that is going to be received. In fact, there is no way to retrieve the amount of tokens received before the actual swap has been executed.

A workaround for this problem would be to track the token balance before and after the swap, and then take the difference of that.