Harmony launch cross-chain NFT bridge

Harmony protocol launches cross-chain NFT bridge as part of the Horizon bridge. (https://bridge.harmony.one)

Users may bridge ERC721/ERC1155 tokens from Ethereum to Harmony and vice versa. It is an important step of the cross-chain infrastructure provided by Harmony to enable a multi-chain ecosystem and one step closer to the upcoming metaverse.

Cross-chain NFT bridge is as easy-to-use as the ERC20 token bridge on Horizon. There is a short video to demonstrate how to use the NFT bridge. (https://www.youtube.com/watch?v=xmPYG0XxFNk) The current implementation of the cross-chain NFT bridge also supports verified checking of NFT in OpenSea API to identify verified NFT collections on Ethereum. The bridged NFT is a plain NFT token, with the same, un-mutable URI that the original NFT points to. It will not work for NFT projects that URI is updated with time.

Why does Harmony provide a cross-chain NFT bridge? What's the usage and benefit provided to our users?

First of all, as admitted by Vitalik in this post, the high gas fee on Ethereum may stop new users and artists from participating in the NFT ecosystem. Thus, new artists and collectors are choosing low-fee blockchains such as Harmony to mint and collect their NFTs. NFTs bridged to a low-fee blockchain like Harmony will also benefit from the lower transaction cost and transfer fees. You may argue that the cost to bridge an NFT from Ethereum to Harmony is still costly. That's true for the initial cost. However, the subsequent transactions won't incur high transaction fees. This is particularly useful for high-frequent trading NFTs such as GameFi equipment or outfits. For high-value NFTs, such as the CryptoPunks or BAYC, it may seem not necessary to bridge them into a low-fee chain like Harmony, however, there are use-cases like NFT lending or fractionalization that may benefit from lower-fee to reduce the fee frictions.

Secondly, the NFT bridge will benefit native NFTs minted on the Harmony blockchain. Young talents or emerging artists may choose Harmony blockchain to mint their first batch of NFTs as a way to test the water of the market or just learn how to use blockchain. When the market starts to appreciate their art pieces, it is possible for the artists to bridge the NFTs to multiple blockchains with more exposure to the public and collectors. Don't forget many artists are unknown and sell relatively cheaper art pieces in the early days of their careers.

We are living in a multi-chain world already and we are embracing the upcoming metaverse. The multi-chain world and the metaverse require inter-connected blockchains, not just the fungible tokens, but also non-fungible tokens. A bridging infrastructure may empower new kinds of dApps to be built, such as games cross multiple chains. For #pfp users, their profile may be portable to multiple blockchains with support from various dApps.

When Facebook changed the name to "Meta", we knew we are still in the burgeoning era of the metaverse; There are unlimited possibilities for dApp developers to build a richer NFT ecosystem. Harmony is keen to provide the best infrastructure in this multi-chain world, starting with bridges.

Again, this is the first implementation of the cross-chain NFT bridge with a semi-trusted setup. On our roadmap, we may support rollup to hugely reduce the gas fee during the bridge process based on Vitalik's proposal. Also, the NFT verification and collection group features are also been planned. We believe and practice the approach to bring the best research into production.

Feel free to apply for NFT grants on https://harmony.one/nft and https://harmony.one/300. Let's build the metaverse together!