WinPay

Win.so crypto payments manager contract

Overview

The WinPay contract is dedicated to handling payments in stable coins for service.

To start accepting payments the service must be registered in the contract.

Every payment can be limited in time, so if your offer has expiration your payments will arrive in time or not at all.

Every payment will be linked to the unique service Id to make a reference between your off-chain accounting system and on-chain payment in crypto.

WinPay can handle payments supporting permit (EIP2612) feature.

For security sake balances and funds are separated in to different types of contracts. Balances are handled by the Ledger contract but funds sre handled by Asset-type of contracts. Every crypto asset supported by the WinPay must have its dedicated Asset instance. Every service provider can create his own Asset contract.

Assets in WinPay can be regular ERC20 tokens of wrapped ERC20 tokens. In the second case customers will be able to pay using native tokens (they are will be automatically wrapped).

Contract architecture

flowchart TD
  win[WinPay]
  ledger[Ledger]
  asset[Asset]

  win -- authorized at --> ledger
  asset -- authorized at -->  ledger

  win -- joins assets to --> asset
  win -- updates balance --> ledger
  asset -- updates balance --> ledger

Use cases

Making a deal

The customer wants to pay for the service using his tokens (stable coins or native tokens).

To make a deal he has to know:

• the provider Id (unique bytes32 string)
• the service Id (unique bytes32 string)
• the service offer expiration time (if this time will be reached but the deal will not be done the transaction will be reverted)
• address of the proper Asset contract
• the value of the asset (the service cost)

Optionally, if he wants to pay with tokens but won't to send approval transaction and the token supports EIP2612 the customer can generate permit signature and payment will be made automatically.

Using known information the customer should call one of two variants of the deal function (with and without permit).

The deal refund

The service provider wants to refund funds paid by the customer.

To refund funds he has to know:

• the service Id (unique bytes32 string)
• address of the proper Asset contract

Using known information the provider should call the refund function. If the deal associated with given service Id exists and other conditions are fulfilled the deal will be transferred to the REFUNDED state and funds will be returned to the customer account.

! Current version of the WinPay does not unwrapping wrapped funds during refunds and returns wrapped asset even if the customer made payment with native tokens.

Test node

Local instances of contracts can be automatically deployed in the Hardhat environment using the following command:

yarn hardhat node

Deployments

Deployments info please check from hardhat-deploy artifacts that are located in the ./deployments directory.

Commits

To commit to the repository after staging the commit:

yarn commit

Select the appropriate type of commit message, any issues to close, and note any breaking changes.

Tests

Test are handled with chai and includes solidity-coverage, enabling coverage reports to be done for the code-base. By default, contracts located in contracts/test are ignored by solidity-coverage.

Deployment

Requirements

1. Ensure 100% solidity coverage in tests prior to production deployment.
2. All Ownable contracts MUST have their owner set to the community multi-sig and/or TimelockController. NO contracts must be allowed to retain ANY deployer addresses in their configuration.
3. MINIMUM two reviewers prior to committing to the main branch.

Scripts

This repository uses hardhat-deploy for reproducible deployment tests, as well as:

1. Get contracts via name from ethers.
2. Named accounts for more readable tests.
3. Conditional logic execution based on tagged network deploying to (allowing for more complex logic when deploying across multiple chains, and/or testnets).

Deployment scripts are contained within deploy, and these deployment scripts are executed prior to any tests, and are executed in alphabetical order.

How to use

Unit testing:

yarn test

Coverage analysis:

yarn hardhat coverage

Run deploy scripts and deploy to polygon:

yarn hardhat deploy --network polygon

Now verify the contracts on Etherscan:

yarn hardhat --network mainnet etherscan-verify

NOTE: Substitute mainnet above for the applicable target network.

Scripts

Registering a service provider

yarn hardhat --network sokol registerProvider --owner 0x2aAe83D2e734fA7A586C1C981175DFAb551fb512 --address 0x6f2fBD652A99Db4b8143c8383Ae39b5459268685 --provider win_win_provider

> Provider registration tx:  0x4d6933e2097acc6be2ae38e9552876a733865e0602d19501371609aecda572ab
> Provider 0x394e5c06a83eeea7fd8e0e50bb1ff1f13bec1a4e353a9a0f6db9dea030bcbef3 has been registered successfully
           ^^^
           providerId

Minting of test tokens

yarn hardhat --network sokol mintTest --owner 0x2aAe83D2e734fA7A586C1C981175DFAb551fb512 --address 0x0462C345320C7Ed3071cd1426e6B62472C5bA96d --to 0xA0B74BFE28223c9e08d6DBFa74B5bf4Da763f959 --amount 1000000000000000000000000

> Minting tx:  0xcc5eafdf3de6b77e3d133f8320bf44fa31c9d57aae050949c9023fd93048ab30
> 1000000000000000000000000 has been minted to 0xA0B74BFE28223c9e08d6DBFa74B5bf4Da763f959 successfully