Cue

Our app enables normal users to set alerts in web3 for stuff they want to be notified of and enables developers to easily bake rich notification features in their app to increase engagements. We are currently focused on transactional emails as opposed to marketing emails. The app is made from ground up thinking about ease of use - with just 3 steps to set notifiers for normal users and a line of code by which developers can build notifications in their dApp. we support Goerli and Mumbai for the consumer side and for the Devtool part we support Mumbai and Opt-Goerli

For the consumer side of app - we store these notifiers on a database & we use node-schedule package to keep watch on the transaction on the blockchain in 1 min intervals. We use Covalent API and Quicknode's Token API for Polygon and Ethereum network respectively. Once we see a transaction containing a wallet registered in the table, we further match to see if other details match the notifier and then send away the notification. For the Devtool part of the app, we use a table to store notification templates - arranged org-wise with actual templates stored in IPFS, next we have an interface that links up with our contract when provided the contract address and the dev needs to call the sendNotif function when they deem a notification is needed. Then they again register their contract address in our contract. Next a user has to just grant the dApp permission to send wallets. When a notification is triggered, we have oracles to check - a) if the user has given the dApp permission and b) is the contract address registered with us. Confirming both, we receive the wallet address and the notification name in our backend as event logs which we then get down to work with to send notifications. That, is done by searching up the user details and notification details in the tables, then we construct an email with that and send away! Tellor's oracles, Tableland's databases, Quicknode and Covalent's powerful APIs were extremely pivotal to a successful build. We also benefitted from the lightning-quick opt-goerli and polygon Mumbai chains. We first thought of using SBTs to check if a company has the rights to send notifications to a user, but as we couldn't find a standard for it, we stored the data in Tableland and just used oracles. When I pitched this idea in the idea-brainstorming session, all the mentors said this would a hack-and-a-half even if I could complete it, now that I have done it, I and my teammate are very proud of what we've managed to pull off!