The problem XMTPay solves

Integrated messaging and payments are an essential part of today's economy -- XMTPay helps manage this in a standalone app that's multi-chain and permissionless. Chat and send payments seamlessly using a client-managed list of contacts and trusted accounts, and get alerts if the account you're about to send money to is up to no good. The platform can be extended to fit any number of custom, user-built functionalities with XMTP bot accounts and group chats.

Challenges we ran into

First off, we had a scope challenge -- as a team of two, what was feasible for us to accomplish where there are so many applications for wallet-based chat? We decided to narrow the scope to two major features -- send and request a payment, and an integrated security check using Harpie as a preventative measure against scams and phishing attacks. Past that, some of the functionality we wanted was either still in development (XMTP group chats for a 'split the bill n ways' feature) as well as what appeared to be an outage on Harpie's API.

In addition to that, dealing with the custom message encoding / decoding and reply structure of XMTP was something of a challenge.