Team Members

@Gpaul26 - Team Leader

@ChienMaiDinh - Developers

@hunteran - Developers

@pctsvn - Developers

@TuanAnh1196 - Developers

Description XGift is a decentralized application (dApp) that provides a new way to send and receive gifts in the form of gifs and ETH. Designed with application-specific chaining and scrolling properties, XGift allows users to create gift links on the Base Sepolia network, which can then be claimed on the OP Sepolia network, receiving ETH gifts as part of the claims process.

This DApp uses Polymer x IBC as the cross-chain format to seamlessly connect the two networks, ensuring a smooth and intuitive user experience. Whether you're new to the Base network or a seasoned OP user, XGift provides an engaging and rewarding way to explore the possibilities of both chains.

Features:

Use Polymer x IBC as the cross-chain format. Committing to the ethos of application-specific chains/rollups, where gif creation functionality can be specialized on one chain, and gif claiming on another chain. Resources used The repo uses the ibc-app-solidity-template as starting point and adds custom contracts XGiftVault and XGift that implement the custom logic.

It changes the send-packet.js script slightly to adjust to the custom logic.

The expected behaviour from the template should still work but nevertheless we quickly review the steps for the user to test the application... Run just --list for a full overview of the just commands.

Additional resources used:

Hardhat Blockscout Tenderly Steps to reproduce After cloning the repo, install dependencies:

just install And add your private key to the .env file (rename it from .env.example).

Then make sure that the config has the right contracts:

just set-contracts optimism XGift false && just set-contracts base XGiftVault false Note: The order matters here! Make sure to have the exact configuration

Check if the contracts compile:

just compile Deployment and creating channels (optional) Then you can deploy the contract if you want to have a custom version, but you can use the provided contract addresses that are prefilled in the config. If using the default, you can skip to the step to send packets.

If you want to deploy your own, run:

just deploy optimism base and create a channel:

just create-channel Create a gift just create-gift-link base Check list gift by receiver address just list-gift optimism Claim gift Please pick gift id in list gifts and edit receiver address in file scripts/gift/claim-gif.js

just claim-gift optimism Proof of testnet interaction After following the steps above you should have interacted with the testnet. You can check this at the IBC Explorer.

Here's the data of our application:

XGiftValue (Base Sepolia) : 0x6101c78e408B1e63ac7a9519054c6564Da758467

XGift (OP Sepolia): 0xdC828bf7a839Abef63A9bd4a436E8E432DEadea2

Channel (OP Sepolia): channel-39944

Channel (Base Sepolia): channel-39945

Proof of Create Gift:

SendTx RecvTx Ack Proof of Claim Gift:

SendTx RecvTx Ack Challenges Faced Debugging used to be tricky when the sendPacket on the contract was successfully submitted but there was an error further down the packet lifecycle. What helped was to verify the contracts and use Tenderly for step-by-step debugging to see what the relayers submitted to the dispatcher etc. What we learned How to make the first dApp using Polymer.

Future improvements Basic functionality was implemented, but the following things can be improved:

More tests More input validation Add event listeners related to important IBC lifecycle steps Licence Apache 2.0