Integrating the DEX into Aptosphere was probably the toughest part of the project. It was a long, sometimes frustrating process, and I hit a few roadblocks along the way. First, I had to choose which wallet to support and finally settled on the Martian wallet. Then, when it came to building the DEX, I found the Liquidswap SDK, which was a lifesaver, but finding the right token addresses on the Aptos chain and making sure the pools existed was a real headache.

I decided to stick with some basic tokens like USDT, USDC, USDD, and WETH and started testing the code. I originally wanted to test everything on the devnet before moving to the mainnet, but there weren’t any token addresses or pools available on the devnet. My code kept throwing errors, so I had no choice but to test directly on the mainnet.

Initially, I thought it would be best to create a new account for each user who connected their wallet to Aptosphere. The idea was that the user would transfer tokens to this account, I’d perform the swap, and then send the tokens back. But I quickly realized that each new account needed some initial funding and setup before it could even handle swaps, which made the whole process way more complicated than it needed to be. So, I switched gears and decided to use a single, predefined account where all users would send their tokens for swapping.

Another snag I hit was with calculating how much of one token a user would get when swapping for another. My initial calculations didn’t factor in gas fees, which led to some inaccurate estimates. To fix this, I ran a bunch of test transactions, figured out the average gas used for each type of token, and then hardcoded that value into the calculations.

Finally, there was the issue with token decimals. Aptos tokens have 8 decimal places, but other tokens typically have 6. I had to create a function to handle this difference and make sure everything converted correctly during transactions.