• We announced an exciting hackathon 👉 Go here to register for it 👈
  • This article describes our “wish list” of applications we’d love to see developers at the hackathon build.

Harmony is excited to bring the Horizon ONE-ETH bridge and community Swoop cross-chain DEX as open platforms for developers to build upon. Our mainnet has 5-second finality and EVM compatibility. Combined with the Horizon bridge, developers can seamlessly port dApps and liquidity.

For this hackathon, we are looking to build our ecosystem in 3 major categories:

  1. Cross-chain infrastructure
  2. Decentralized finance showcases
  3. Fiat utility products

In the coming days, we’ll also post more technical details about our tooling and documentation.

We are focused on bridging Harmony with other layer 1 blockchains. We are looking for developers to build protocols for cross-chain lending, DEX and additional components for the trustless Horizon bridge.

  • Cross-chain lending protocols: create a money market lending protocol that allows users to lock assets on Ethereum and access an equivalent value of assets on Harmony, and vice versa. The protocol should be non-custodial and could include an additional mechanism to immediately provide liquidity for assets transferred cross-chain for a fee. Reference projects: Blits, Bandot, Equilibrium.
  • Cross-chain liquidity: build a cross-chain DEX aggregator that allows users to get liquidity and the best prices across different DeFi products including cross-chain DEXes. Reference projects: Polkastarter, Zenlink, 1inch.
    Developers can also build out cross-chain liquidity pools. Reference projects: Bridgepool.
  • Related, build bots /smart contracts that identify arbitrage opportunities across chains and automatically fulfills orders.
  • Cross chain staking derivatives: build a protocol for users to stake ONEs on Harmony and receive a derivative token on Ethereum to use in other applications. Reference project: yNear.
  • Build out components for Harmony’s trustless Horizon bridge including:
    Provers: a program that provides a proof of user transaction.
    Relayers: downloads blocks from chains, extracts relevant information and sends it to light client smart contracts.
    Light clients and verifiers: smart contracts that maintain cross-chain information and verifies the proofs sent by the user.
  • Build ONE<>BTC (using XCLAIM and BTC-Relay) bridge components:
    Port BTC-Relay (a stateful SPV client for Bitcoin) as a Harmony smart contract that stores BTC headers and verifies merkle proofs
  • Implement the ONE-BTC issue and redeem protocols
  • Vault manager modules for vault register and replace, and treasury smart contract for handling of the ONE-BTC currency (mint, transfer, lock, burn)
    Collateral module that handles locking, releasing and slashing of collateral & exchange rate manager for getting oracle price
  • Staked relayers & security module that handles registration and stake of Staked Relayers as well as voting on bridge status changes
  • Harmony has integrated the Rosetta API. Create a new CLI tool specific to Harmony to view blocks, transactions, sign transactions, deploy contracts view chain information, etc.

DeFi Showcases

We are looking for developers to build and port finance protocols utilizing our Horizon bridge. Bridge liquidity from Ethereum and demonstrate applications that take advantage of Harmony’s fast finality and low fees.

  • Swoop DEX: fork the Swoop cross-chain DEX and build additional components including a governance token, similar to the UNI token for Uniswap, dashboard info, mobile wallet support and analytic page with all user and pool information/earnings.
  • DEX ecosystem: build out other features for DEXes including integrating with centralized and decentralized exchanges to bring liquidity, on-chain oracles, and arbitrage bots to mitigate price discrepancies. Also build stop loss protocols to protect liquidity providers against impermanent losses. Reference projects: Reef, Stoploss,
  • On-chain decentralized order book: implement a matching engine as a smart contract on Harmony that also allows users to create limit orders for trading pairs. Reference projects: NearBook.
  • Money market lending protocol native on Harmony: build both lending protocols and aggregators with a single interface consolidating lending protocols, including cross-chain protocols, for the best rates. This also could include aggregators for yield farming. Reference projects: Juicer Protocol.
  • Tokenized synthetic assets: build an issuance protocol to mint and support tokenized synthetic assets using Chainlink and Band oracles and listing the assets on Swoop or other Harmony DEXes. Reference projects: Demeter, Laminar.

Fiat Utility

Build integrations that would allow fiat currency holders to access ONE and HRC20 tokens and connect ONE to fiat merchants and users.

  • Fiat loans & lending: build an app for users to deposit Harmony ONE token and receive a fiat (USD, EURO, etc.) loan at a specific collateral ratio. Reference projects: Nexo, Blockfi.
  • Remittance and vouchers: allow users to send remittance in the form of cash or gift cards and vouchers across borders to their home countries. Reference projects: Swych, MoneyHome.
  • Fiat gateways: build a non-custodial peer-to-peer on/off ramp for ONE tokens and fiat currencies using open banking API for country markets such as India and other countries. Reference projects: Unipeer.
  • Decentralized currency pegged stablecoins: build a digital currency that keeps a 1:1 peg to the price of that currency with a primary market that buys/sells for the spot rate of 1:1 currency or another mechanism. Reference projects: DEUR, El Dorado.
  • Integrations with fiat gateways and merchants: integrate ONE for payments and allow merchants to accept ONE while denominating and settling sales in their national currency. Reference projects: Coinqvest.
  • Investment products: build applications that allow users to invest in a derivative of the equity of any company. Reference projects: DSTOQ.

We are excited to build our cross-chain finance infrastructure ecosystem together with our community! Learn more about the full hackathon details at and talk to our team on our Discord community.