DeFi Adapter Kit

Starter kit for defi adapter development compatible with Opty-Fi's earn-protocol

Prerequisites

• Install Node JS >= v12.0.0
• Learn Javascript and Typescript
• Learn Solidity >=v0.6.12.
• Learn smart contract development environment like Hardhat
• Learn testing framework like mocha
• Learn assertion library like chai

And passion for financial freedom...

Getting started

Development Setup

• Create a .env file and set a BIP-39 compatible mnemonic as an environment variable. Follow the example in .env.example. If you don't already have a mnemonic, use this website to generate one.
• You will require access to archive Node URL for forking the mainnet.

Proceed with installing dependencies:

yarn install

What is a DeFiAdapter

• DeFi adapter is a vital building block for executing opty.fi's network of strategies.
• Specifications for DeFi adapter help perform :
  • transactions like deposit, withdraw, staking, un-staking, adding liquidity, claim reward and harvesting of the reward.
  • read calls for liquidity pool token contract address, liquidity pool token balance, staked token balance, balance in underlying token of both staked and non-staked liquidity pool token, unclaimed reward tokens and reward token contract address
• A DeFi Adapter smart contract requires implementation of following interfaces :
  • IAdapter.sol (Mandatory)
  • IAdapterHarvestReward.sol (Optional)
  • IAdapterStaking.sol (Optional)
  • IAdapterBorrow.sol (Optional)
  • IAdapterInvestmentLimit.sol (Optional)

Pro Tip : Inherit IAdapterFull interface from IAdapterFull.sol to Adapter Contract if the protocol you choose required implementation of all the above interfaces.

Developing DeFiAdapter

Step #1 - Use this template

• This is a GitHub template, so click on green button "Use this template" on the top-right corner of the page to create new defi adapter.

Step #2 - Pool, LP token and underlying token(s) address gathering

• Choose a DeFi protocol and gather the pool contract addresses similar to harvest.finance-pools.json.

Step #3 - Implementing IAdapter interface

• Implement an adapter contract using above interface(s) similar to HarvestFinanceAdapter.sol

Step #4 - Unit Tests

• Write unit tests for all the functions across all the pool contracts gathered in Step 1.
• You might want to use a test utility contract like TestDeFiAdapter for creating a sandbox environment to execute the transaction based on function signature and target address returned from getCodes()-style functions from DeFiAdapter.
• All other functions can be directly tested from the DeFiAdapter contract.
• The unit test for HarvestFinanceAdapter.sol can be found in HarvestFinanceAdapter.ts

Useful commands

Usage	Command
Compile the smart contracts with Hardhat	$ yarn compile
Compile the smart contracts and generate TypeChain artifacts	$ yarn typechain
Lint the Solidity Code	$ yarn lint:sol
Lint the TypeScript Code	$ yarn lint:ts
Run the Mocha tests	$ yarn test
Generate the code coverage report	$ yarn coverage
Delete the smart contract artifacts, the coverage reports and the Hardhat cache	$ yarn clean
Deploy the adapter to Hardhat Network	$ yarn deploy

Syntax Highlighting

If you use VSCode, you can enjoy syntax highlighting for your Solidity code via the vscode-solidity extension. The recommended approach to set the compiler version is to add the following fields to your VSCode user settings:

{
  "solidity.compileUsingRemoteVersion": "v0.6.12+commit.27d51765",
  "solidity.defaultCompiler": "remote"
}

Where of course v0.6.12+commit.27d51765 can be replaced with any other version.

References

• Hardhat
• Ethereum Development Documentation
• Harvest Finance Docs