Cross-Chain API

This project will create a CrossChain API MVP that allows:

  • Liquidity Providers (LPs) - that have tokens in Ethereum & BSC to add liquidity in Harmony DEXs using a single API
  • Swappers - to move their tokens from/to Ethereum and BSC using a single API


The expected deliverables are

  • Following 4 APIs:
    • LP-Explore
    • LP-AddLiquidity
    • LP-RemoveLiquidity
    • Swapper-Explore
    • Swapper-Swap
  • A client (web-based) that utilizes the aforementioned crosschain apis to explore and perform crosschain activities like adding/removing liquidity, swapping tokens to/from BSC and Ethereum. Work on this client has already started.


All functionality is being developed in Production mode, where the API takes hashes of signed transactions, and Development mode, where the server is run locally and the API takes the PK.

Step-by-step LP

  • Add Liquidity (Alpha) - Alpha Version: 10/04/2021
  • Remove Liquidity (Alpha) - Alpha Version: 10/04/2021
  • Add Liquidity (Beta) - 10/20/2021
  • Remove Liquidity (Beta) - 10/20/2021

Step-by-step Swapper

  • Bridge Approval and Lock - Production and Development (Beta)
  • Bridge Approval, Deposit and Burn - Production and Development (Beta)
  • DEX - Viper Swap - Production and Development (Beta)
  • AWS Deployment (development) - Beta Version: 10/15/2021
  • DEX - Sushi (Pending) - Beta Version: 10/30/2021
  • DEX - Kanga (Pending) - Beta Version: TBD

End2end LP

  • Integration of Add Liquidity functionality into End2End swapper (Pending)

End2end Swapper

  • Combo API call that bridges assets from ETH BUSD into Harmony BUSD (Harmony Bridged Asset), then swaps Harmony BUSD into bscBUSD (Harmony Bridged Asset) on Viper and finally bridges bscBUSD into BUSD in BSC. (Beta)
  • Combo API call that bridges assets from BUSD in BSC into bscBUSD (Harmony Bridged Asset), then swaps bscBUSD into Harmony BUSD (Harmony Bridged Asset) on Viper and finally bridges Harmony BUSD into ETH BUSD. (Development/Refactoring) - Beta Version: 09/27/2021
  • AWS Deployment (development) - Beta Version: 10/15/2021
  • Integration with Sushi (pending) - Beta Version: 10/30/2021
  • Integration with Kanga (pending) - Beta Version: TBD

Explore APIs

  • Share of Pool Metrics in Viper (Alpha) - Alpha Version: 10/08/2021
  • Gas costs (Alpha) - Alpha Version: 10/08/2021
  • APY (Development) - Alpha Version: 10/22/2021
  • Slippage (Development) - Alpha Version: 10/22/2021
  • Share of Pool Metrics (Beta) - Beta Version: 10/20/2021
  • Has Costs (Beta) - Beta Version: 10/20/2021

Meta transactions

  • General Contract Manager that can aggregate signature of multiple hashes for Bridging (Development) - Alpha Version: 01/11/2021


  • Automated Platform for the aggregation of multiple DEXs (Pending) - Alpha Version: 12/01/2021

Web Client

  • Web Client that implements API functionality - Alpha Version: 12/01/2021
  • Define Web client functionality - Version for open discussion and approval 10/15/2021
  • Enroll Collaborator to develop front-end

Development Updates

Week 10/03 - 10/10

  • Received feedback from beta-testers and suggested changes are being implemented
  • Development of UI testnet started
  • Simple mainnet transactions were successful
  • Containerization is complete

Week 10/18 - 10/25

  • Alpha for UI client is live

  • Debugging for API backend is complete
  • Deployed to AWS in test server