@depay/web3-payments

JavaScript library to scan crypto wallets for liquefiable assets and calculate most cost-effective payment routing.

Usage no npm install needed!

<script type="module">
  import depayWeb3Payments from 'https://cdn.skypack.dev/@depay/web3-payments';
</script>

README

Quickstart

yarn add @depay/web3-payments

or

npm install --save @depay/web3-payments

import { route } from '@depay/web3-payments'

let paymentRoutes = await route({
  accept: [{
    blockchain: 'ethereum',
    token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
    amount: 20,
    fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
    toAddress: '0xb0252f13850a4823706607524de0b146820F2240'
  }],
  apiKey: 'YOUR-API-KEY'
})

This requires you to have a DePay PRO apiKey.

Functionalities

route

Routes payment and returns payment routes:

import { route } from '@depay/web3-payments'

let paymentRoutes = await route({
  accept: [{
    blockchain: 'ethereum',
    token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
    amount: 20,
    fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
    toAddress: '0xb0252f13850a4823706607524de0b146820F2240'
  }],
  apiKey: 'YOUR-API-KEY'
})

Also allows to pass in multiple accepted means of payment:

import { route } from '@depay/web3-payments'

let paymentRoutes = await route({
  accept: [
    {
      blockchain: 'ethereum',
      token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
      amount: 20,
      fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
      toAddress: '0xb0252f13850a4823706607524de0b146820F2240'
    },{
      blockchain: 'bsc',
      token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
      amount: 20,
      fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
      toAddress: '0xb0252f13850a4823706607524de0b146820F2240'
    }
  ],
  apiKey: 'YOUR-API-KEY'
})

fromToken + fromAmount + toToken

In cases where you want to set the fromToken and fromAmount (instead of the target token and the target amount) when calculating payment routes you can pass fromToken, fromAmount + toToken.

Make sure to NOT pass token nor amount if you use that option!

import { route } from '@depay/web3-payments'

let paymentRoutes = await route({
  accept: [
    {
      blockchain: 'bsc',
      fromAmount: 1,
      fromToken: '0xe9e7cea3dedca5984780bafc599bd69add087d56',
      toToken: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
      fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
      toAddress: '0xb0252f13850a4823706607524de0b146820F2240'
    }
  ],
  apiKey: 'YOUR-API-KEY'
})

Pay into Smart Contracts

In case you want to pay into smart contract (calling a smart contract method), you will need to pass toContract in addition to toAddress:

import { route } from '@depay/web3-payments'

let paymentRoutes = await route({
  accept: [
    {
      blockchain: 'ethereum',
      token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
      amount: 20,
      fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
      toAddress: '0xb0252f13850a4823706607524de0b146820F2240',
      toContract: {
        signature: 'claim(address,uint256,bool)',
        params: ['true']
      }
    }
  ]
})

To contract needs to contain at lest the signature field. Depending on the signature field params also need to be provided.

The previous example after swapping payment tokens, will call the contract at 0xb0252f13850a4823706607524de0b146820F2240 calling method claim passing address from the payment sender and amounts from the final token amounts also forwarding params[0] to pass the value for bool.

If you want to know more about paying into smart contracts, checkout the depay-evm-router.

Read following the currently supported contract call signatures:

signature(address,uint256,bool)
While inferring uint256 from paid amount:
import { route } from '@depay/web3-payments'

let paymentRoutes = await route({
  accept: [
    {
      blockchain: 'ethereum',
      token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
      amount: 20,
      fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
      toAddress: '0xb0252f13850a4823706607524de0b146820F2240',
      toContract: {
        signature: 'claim(address,uint256,bool)',
        params: ['true']
      }
    }
  ]
})
Passing uint256 explicitly:
import { route } from '@depay/web3-payments'

let paymentRoutes = await route({
  accept: [
    {
      blockchain: 'ethereum',
      token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
      amount: 20,
      fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
      toAddress: '0xb0252f13850a4823706607524de0b146820F2240',
      toContract: {
        signature: 'claim(address,uint256,bool)',
        params: ['40000000000000000000', 'true']
      }
    }
  ]
})

whitelist

Allows only fromTokens (from the sender) that are part of the whitelist:

let paymentRoutes = await route({

  whitelist: {
    ethereum: [
      '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE', // ETH
      '0xdac17f958d2ee523a2206206994597c13d831ec7', // USDT
      '0x6b175474e89094c44da98b954eedeac495271d0f'  // DAI
    ],
    bsc: [
      '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE', // BNB
      '0xe9e7cea3dedca5984780bafc599bd69add087d56', // BUSD
      '0x55d398326f99059ff775485246999027b3197955'  // BSC-USD
    ]
  }
})

blacklist

Filters fromTokens to not be used for payment routing:

let paymentRoutes = await route({

  blacklist: {
    ethereum: [
      '0x6b175474e89094c44da98b954eedeac495271d0f'  // DAI
    ],
    bsc: [
      '0x55d398326f99059ff775485246999027b3197955'  // BSC-USD
    ]
  }
})

event

Allows to emit events as part of the payment transaction.

DePayRouterV1PaymentEvent02

Possible values:

ifSwapped: Only emits an event if payment requires swap, otherwise no dedicated payment event is emited. Use classic transfer event in case of a direct payment (does not go through the DePay router).

let paymentRoutes = await route({
  accept: [
    {
      blockchain: 'ethereum',
      token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
      amount: 20,
      fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
      toAddress: '0xb0252f13850a4823706607524de0b146820F2240'
    },{
      blockchain: 'bsc',
      token: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
      amount: 20,
      fromAddress: '0x5Af489c8786A018EC4814194dC8048be1007e390',
      toAddress: '0xb0252f13850a4823706607524de0b146820F2240'
    }
  ],
  apiKey: 'YOUR-API-KEY',
  event: 'ifSwapped'
})

Events are not emitted if payment receiver is a smart contract. Make sure your smart contract emits events in that case!

fee

route allows you also to configure a fee that is taken from the payment amount and is sent to another receiver (the fee receiver):

let paymentRoutes = await route({
  accept: [...],
  fee: {
    amount: '3%',
    receiver: '0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B'
  }
})

// splits 0.3 of the amount paid and sends it to the feeReceiver

fee.amount can be passed as percentage (String with ending %) or as a BigNumber string or as a pure number/decimal

let paymentRoutes = await route({
  accept: [...],
  fee: {
    amount: '300000000000000000',
    receiver: '0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B'
  }
})
// splits 0.3 of the amount paid and sends it to the feeReceiver

let paymentRoutes = await route({
  accept: [...],
  fee: {
    amount: 0.3,
    receiver: '0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B'
  }
})
// splits 0.3 of the amount paid and sends it to the feeReceiver

routers

Exports basic router information (address and api):

import { routers } from '@depay/web3-payments'

routers.ethereum.address // 0xae60aC8e69414C2Dc362D0e6a03af643d1D85b92

plugins

Exports plugin addresses:

import { plugins } from '@depay/web3-payments'

plugins.ethereum.payment // 0x99F3F4685a7178F26EB4F4Ca8B75a1724F1577B9

Domain Knowledge

Payment Routing Priorities

  1. If user has request token in his wallet, direct token transfer to receiver will be prioritized

  2. Any token that can be liquidated on decentralized exchange and has been already been approved for the DePay router will be second priority

  3. All other liquefiable tokens that still require token approval will be prioritized last

Data Structures

PaymentRoute

Payment routes are provided in the following structure:

{
  blockchain: String (e.g. ethereum)
  fromToken: Token (see @depay/web3-tokens)
  fromBalance: BigNumber (e.g. <BigNumber '10000000000000000000'>)
  fromAddress: String (e.g. '0xd8da6bf26964af9d7eed9e03e53415d37aa96045')
  fromAmount: BigNumber (e.g. <BigNumber '31000000000000000000'>)
  fromDecimals: number (e.g. 18)
  toToken: Token (see @depay/web3-tokens)
  toAmount: BigNumber (e.g. <BigNumber '21000000000000000000'>)
  toDecimals: number (e.g. 18)
  toAddress: String (e.g. '0x65aBbdEd9B937E38480A50eca85A8E4D2c8350E4')
  exchangeRoutes: Array (list of exchange routes offering to convert )
  transaction: Transaction (see @depay/web3-wallets for details)
  approvalRequired: Boolean (e.g. true)
  approvalTransaction: Transaction (to approve the fromToken being used from the payment router to perform the payment)
  directTransfer: Boolean (e.g. true)
}

approvalRequired: indicates if a upfront token approval is required in order to perform the payment, make sure you execute approve before executing the payment transaction itself.

directTransfer: indicates if the payment does not require any swapping/exchanging.

See @depay/web3-wallets for details about the transaction format.

Support

This library supports the following blockchains:

This library supports the following decentralized exchanges:

Soon:

Development

Get started

yarn install
yarn dev

Release

npm publish