# Track 1a: Cross-Chain - "Liquidity" **URL:** \ **Category:** Archive\ **Created:** [August 10, 2021, 12:33am UTC](https://talk.harmony.one/t/track-1a-cross-chain-liquidity/1969 "2021-08-10T00:33:24Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![lij](https://yyz1.discourse-cdn.com/flex035/user_avatar/talk.harmony.one/lij/32/14351_2.png) [@lij](https://talk.harmony.one/u/lij)\ **Post date:** [August 10, 2021, 12:33am UTC](https://talk.harmony.one/t/track-1a-cross-chain-liquidity/1969/1 "2021-08-10T00:33:24Z")
**Cross-Chain with Trustless Bridges** **Track 1: Liquidity. Harmony Cross-Chain API for aggregation, Hummingbot for arbitrage, fixed-rate w/ Terra’s UST** * * * The first hackathon theme is _Cross-Chain_ with our trustless, on-chain bridges. The 4 tracks — Liquidity, Middlewares, DeFi/NFT/DAO, Platform — emphasize the current **product-market fits** of decentralized applications but across multiple chains. Developers can make use of Harmony’s rich ecosystem: a cross-chain API for aggregation and asset pools; Ethereum-compatible indexing, names, and toolkits; and, unique technical features including randomness opcode, on-chain delegation and aggregated signatures, FlyClient bridges, and fast state sync with message gossips. Besides advancing these cross-chain infrastructure, there are also many product ideas that can take advantage of our trustless bridges. For example, building **arbitrage bots** with our partner Hummingbot or integrating stablecoins and saving products with our Terra bridge. Harmony has also launched Bulletproof and Poseidon Hash functions for privacy coin mixers like Tornado Cash. ([more](http://harmony.one/horizon)) ![image](https://canada1.discourse-cdn.com/flex035/uploads/harmony1/original/1X/91e2d6e8d8cfd22b52af63cdcfeb860dc646b767.png) ---
**Author:** ![john\_whitton](https://yyz1.discourse-cdn.com/flex035/user_avatar/talk.harmony.one/john_whitton/32/3875_2.png) [@john\_whitton](https://talk.harmony.one/u/john_whitton)\ **Post date:** [August 25, 2021, 12:37am UTC](https://talk.harmony.one/t/track-1a-cross-chain-liquidity/1969/3 "2021-08-25T00:37:54Z")
To kick things off, I’ll be spotlighting **Track 1: Cross-Chain - “Liquidity”** - Aggregation, Arbitrage and Fixed Income. As the world moves towards multi-chain with bridges between the major blockchains, we’ll need projects to aggregate liquidity across multiple chains. Projects can build tools for capturing arbitrage opportunities between liquidity pools on multiple chains. Developers may also build lending products that allow collateral of assets on one chain and lending of assets on another chain. Strategy: [Harmony’s Vision on Cross-Chain & Cross-Exchange Pools](https://blog.harmony.one/harmony-roadmap-cross-chain-cross-exchange-pools/) Examples & References: [fixed-rate income](https://twitter.com/stse/status/1378169647837552642), [sushi’s kashi: lending](https://blog.harmony.one/sushi-and-harmony-announce-full-stack-partnership-with-4m-in-incentives/), [limit order](https://medium.com/dragonfly-research/unbundling-uniswap-the-future-of-on-chain-market-making-1c7d6948d570), [cross-exchange](https://hummingbot.io/blog/2020-09-what-is-cross-exchange-market-making) Harmony Developer Guides: [Getting Started](https://docs.harmony.one/home/developers/getting-started), [Harmony Stack and Projects](https://docs.harmony.one/home/developers/harmony-stack), [Deployed Contracts](https://docs.harmony.one/home/developers/list-of-deployed-contracts) Harmony Hackathon Repository : [Has sample projects and links to hackathon information](https://github.com/harmony-one/hackathon) ## Sources for Ideas Cross Chain Liquidity leverages Cross Chain Bridges the corner stone for Harmony is the Horizon bridge currently supporting Ethereum and Binance Smart chain. If you are interested in building bridges to other chains or working with teams that are please check out the track for [Cross-Chain - “Platform”](https://talk.harmony.one/t/track-4-cross-chain-platform/1972). Below is an overview of Bridging as well as some relevant research and github repositories for projects which are working in this space. For more information on Harmony’s Ecosystem and projects of interest see [here](https://docs.harmony.one/home/developers/harmony-stack). For Fixed Income we have listed a number of lending and staking protocols designed to give token holders a return which can provide a fixed income. Interesting areas include staking derivatives, lending protocols, and other financial derivatives. ### Research and Repositories - Aggregation - [1inch](https://1inch.io/aggregation-protocol/) - [docs](https://docs.1inch.io/api/), [api](https://api.1inch.exchange/swagger/ethereum/), [github](https://github.com/1inch/1inchProtocol) - [Sushi](https://sushi.com/) - [trident](https://medium.com/sushiswap-org/introducing-the-sushi-next-generation-amm-trident-7dea6aa3cbc2), [mirin](https://github.com/sushiswap/mirin), [github](https://github.com/sushiswap/sushiswap) - [paraswap](https://paraswap.io/#/?network=ethereum) - [docs](https://doc.paraswap.network/), [github](https://github.com/paraswap) - [0x](https://0x.org/) - [docs](https://0x.org/docs), [API](https://0x.org/api), [github](https://github.com/0xProject) - Arbitrage - [Hummingbot](https://hummingbot.io/) - [Academy](https://hummingbot.io/academy), [docs](https://docs.hummingbot.io/developers/), [github](https://github.com/CoinAlpha/hummingbot) - Fixed Income - Sushi (Yield farming) - [kashi](https://docs.sushi.com/products/kashi-lending), [yield farming](https://docs.sushi.com/products/yield-farming) - [AAVE](https://aave.com/) (Lending) - [docs](https://docs.aave.com/portal/), [github](https://github.com/aave/aave-protocol) - [Lido](https://lido.fi/) (Staking Derivatives) - [docs](https://docs.lido.fi/) [github](https://github.com/lidofinance) ### Additional Developer Links - [Developer Docs](https://dev.harmony.one/) - [Getting Started](https://docs.harmony.one/home/developers/getting-started) - [APIs](https://docs.harmony.one/home/developers/api) - [Dapp Templates and Tutorials](https://docs.harmony.one/home/developers/showcases/dapp-samples-on-harmony) - [Codebase](https://github.com/harmony-one) - [Horizon trusted bridge smart contracts](https://github.com/harmony-one/ethhmy-bridge) ## Bridging Overview ### Harmony Bridge - Horizon Ethereum\<\>Harmony two way bridge (trusted version) #### Transferring ERC20 from Ethereum to Harmony [![eth2hmy](https://canada1.discourse-cdn.com/flex035/uploads/harmony1/original/1X/3c9d9a1dc7bf597af788ffff0ed89783887726df.jpeg)](https://github.com/harmony-one/ethhmy-bridge/blob/master/assets/eth2hmy.jpg) #### Transferring HRC20 from Harmony back to Ethereum [![hmy2eth](https://canada1.discourse-cdn.com/flex035/uploads/harmony1/original/1X/4cf9b82dc82063667b301d8325b4eddbfb246f89.jpeg)](https://github.com/harmony-one/ethhmy-bridge/blob/master/assets/hmy2eth.jpg) ### Sample Contracts for Bridging on Testnet ![CrossChain](https://canada1.discourse-cdn.com/flex035/uploads/harmony1/original/1X/0dabcf3ce99253db48ceceb15f7d769654c0dd7b.jpeg) ### Sample Cross Chain Aggregation ![crosschain-aggregator](https://canada1.discourse-cdn.com/flex035/uploads/harmony1/original/1X/15c14e6e6d808ee2870115f8aae2a24537563d74.png) **Ready to build? Sign up at this Gitcoin blurb below!** and **Reply to this thread** > **[buidlbox](https://app.buidlbox.io/)** > > Ongoing and upcoming hackathons. Every buidlers gateway into the digital frontier. ---
**Author:** ![hefajj](https://avatars.discourse-cdn.com/v4/letter/h/779978/32.png) [@hefajj](https://talk.harmony.one/u/hefajj)\ **Post date:** [August 27, 2021, 10:47am UTC](https://talk.harmony.one/t/track-1a-cross-chain-liquidity/1969/4 "2021-08-27T10:47:21Z")
> [@john\_whitton](#): > > **this Gitcoin blurb below!** and **Reply to this** We are signing up at this Gitcoin blurb. Our Repo: > **[GitHub - CoinQuoter/CoinQuoter\_SmartContracts](https://github.com/CoinQuoter/CoinQuoter_SmartContracts)** > > Contribute to CoinQuoter/CoinQuoter\_SmartContracts development by creating an account on GitHub. ---
**Author:** ![Jacksteroo](https://yyz1.discourse-cdn.com/flex035/user_avatar/talk.harmony.one/jacksteroo/32/15609_2.png) [@Jacksteroo](https://talk.harmony.one/u/Jacksteroo)\ **Post date:** [November 27, 2021, 11:07am UTC](https://talk.harmony.one/t/track-1a-cross-chain-liquidity/1969/5 "2021-11-27T11:07:10Z")