@depay/web3-exchanges-evm

Quickstart

``
yarn add @depay/web3-exchanges
`

or

`
npm install --save @depay/web3-exchanges
`

`javascript
import Exchanges from '@depay/web3-exchanges'

Exchanges.uniswap_v2
Exchanges.orca

// scoped

Exchanges.ethereum.uniswap_v2 // Ethereum scoped uniswap_v2
Exchanges.solana.orca

let routes

routes = await Exchanges.route({
blockchain: 'ethereum',
tokenIn: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
tokenOut: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
amountIn: 1
})

routes = await Exchanges.route({
blockchain: 'solana',
tokenIn: 'Es9vMFrzaCERmJfrF4H2FYD4KCoNkY11McCe8BenwNYB',
tokenOut: '4k3Dyjzvzp8eMZWUXbBCjEvwSkkk59S5iCNLY3QrkX6R',
amountIn: 1
})

import { getWallets } from '@depay/web3-wallets'

const wallet = getWallets()[0]
const account = await wallet.account()

// check if prep is required to facilitate swap/exchange
const preparation = await route.getPrep({ account })

let permit2
if(prep?.transaction) {
await wallet.sendTransaction(prep.transaction)
} else if (prep?.signature) {
let signature = await wallet.sign(prep.signature)
permit2 = {...prep.signature.message, signature}
}

// use connected wallet to sign and send the swap transaction
const transaction = await route.getTransaction({ account, permit2 })
wallet.sendTransaction(transaction)

`

Support

This library supports the following blockchains:

- Ethereum
- BNB Smart Chain
- Polygon
- Solana
- Optimism
- Arbitrum
- Fantom
- Avalanche
- Gnosis
- Base
- Worldchain

This library supports the following decentralized exchanges:

Ethereum:
- Uniswap v3
- Uniswap v2
- WETH

BNB Smart Chain:
- PancakeSwap v3
- Uniswap v3
- PancakeSwap v2
- WBNB

Polygon:
- Uniswap v3
- Quickswap
- WMATIC

Solana:
- Orca
- Raydium, only CP (Constant Product) and CL (Concentrated Liquidity) pools

Optimism:
- Uniswap v3
- WETH

Base:
- Uniswap v2
- Uniswap v3
- WETH

Arbitrum:
- Uniswap v3
- WETH

Fantom:
- SpookySwap
- WFTM

Avalanche:
- Trader Joe v2.1
- WAVAX

Gnosis:
- Uniswap v3
- WXDAI

Platform specific packaging

In case you want to use and package only specific platforms, use the platform-specific package:

$3

`javascript
import Exchanges from '@depay/web3-exchanges-evm'
`

$3

`javascript
import Exchanges from '@depay/web3-exchanges-svm'
`

Data Structures

$3

Decentralized exchange data is provided in the following structure:

`
{
name: String (e.g. uniswap_v2)
label: String (e.g. Uniswap v2)
logo: String (base64 encoded PNG)
protocol: String (uniswap_v2, uniswap_v3 etc.)

fee: Array (e.g. [100, 500, 3000, 10000]; available fee teirs on the exchange)
slippage: Boolean (indicates if exchange has slippage)

blockchains: String (e.g. ['ethereum'])
[blockchain]: {
router: Object (contains 'address' and 'api' to interact with the exchange router)
factory: Object (contains 'address' and 'api' to interact with the exchange factory)
pair: Object (contains 'api' to interact with an exchange pair)
quoter: Object (contains 'address' and 'api' to interact with the exchange quoter)
}
}
`

$3

A Swap configuration is fed into the route function:

`
{
blockchain: String (e.g. 'ethereum')
tokenIn: String (e.g. '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb')
tokenOut: String (e.g. '0xdAC17F958D2ee523a2206206994597C13D831ec7')
amountIn: Human Readable Number (e.g. 1.2 and converted internally to BigNumber) or BigNumber if passed as string
amountInMax: Human Readable Number (e.g. 1.2 and converted internally to BigNumber) or BigNumber if passed as string
amountOut: Human Readable Number (e.g. 1.2 and converted internally to BigNumber) or BigNumber if passed as string
amountOutMin: Human Readable Number (e.g. 1.2 and converted internally to BigNumber) or BigNumber if passed as string
}
`

- tokenIn: The token put into the swap (out of wallet)
- amountIn: The exact amount of tokenIn put into the swap (out of wallet)
- amountInMax: The max. amount of tokenIn put into the swap (out of wallet)
- tokenOut: The token expected to come out of the swap (into wallet)
- amountOut: The exact amount of tokenOut expected to come out of the swap (into wallet)
- amountOutMin: The min. amount of tokenOut expected to come out of the swap (into wallet)

The following combinations of provided amounts are possible:

- Pass amountOutMin. Swap will return at least amountOutMin into the wallet. amountIn will be calculated automatically and can vary.
- Pass amountOut. Swap will take at max amountInMax out of the wallet (calculated based on provided, exact amountOut). amountInMax will be calculated automatically and can vary.
- Pass amountInMax. Swap will take at max amountInMax out of the wallet. amountOut will be calculated automatically and can vary.
- Pass amountIn. Swap will return at least amountOutMin into the the wallet (calculated based on provided, exact amountIn). amountOutMin will be calculated automatically and can vary.

$3

Routes are returned by calling route on Exchanges or a single exchange.

A single Route has the following structure:

`
{
blockchain: String (e.g. 'ethereum')
tokenIn: String (e.g. '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb')
decimalsIn: Integer (e.g. 18)
tokenOut: String (e.g. '0xdAC17F958D2ee523a2206206994597C13D831ec7')
decimalsOut: Integer (e.g. 18)
path: Array (e.g. ['0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb', '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2', '0xdAC17F958D2ee523a2206206994597C13D831ec7'])
pools: Object ([{ pool }])
amounts: [BigNumber] (e.g. ['1000000000000000000', '2300000000000000000', '9900000000000000000'])
amountIn: BigNumber (e.g. '1000000000000000000')
amountOutMin: BigNumber (e.g. '32000000000000000000')
amountOut: BigNumber (e.g. '32000000000000000000')
amountInMax: BigNumber (e.g. '1000000000000000000')
exchange: Exchange (see Exchange data structure)
getPrep: async function (returns transaction object for approvals or signature request for permit2)
getTransaction: async function (returns transaction object –> see @depay/web3-wallets for details)
}
`

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

Slippage

This library applies slippage strategies to amounts for the following combinations:

- If amountOutMin is provided, slippage is applied to amountIn.
- If amountOut is provided, slippage is applied to amountInMax.
- If amountInMax is provided, slippage is applied to amountOut.
- If amountIn is provided, slippage is applied to amountOutMax.

$3

Auto slippage applies 0.5% default slippage.

For blockchains that allow to receive quotes for previous blocks (EVM), auto slippage additionally checks for:

- Extreme Direction

- Extreme Base Volatility

And applies a higher than default slippage (0.5%) if required.

#### Extreme Directional Price Change

If there is a clear directional change of the price for the last 3 blocks,
the target price will be projected according to the velocity of the last 3 blocks.

##### Example Extreme Directional Price Change

Current Price: $1'500

Last 3 Blocks: $1'500, $1'470, $1'440

Velocity: $30 per block

Projection: $1'530

Slippage 2%

Slippage of 2% will be applied, because it's higher than default slippage.

_For downwards projections slippage is not required as the transaction would not fail._

#### Extreme Base Volatility

If there is extreme base volatility in the last 3 blocks,
none-directional,
the target price will be the highest price over the last 3 blocks plus the smallest price change over the last 3 blocks.

##### Example Extreme Base Volatility

Current Price: $1'500

Last 3 Blocks: $1'500, $1'490, $1'520

Smallest Change: $10

Highest Price: $1'520

Projection: $1'530 ($1'520 + $10)

Slippage 2%

Slippage of 2% will be applied, because it's higher than default slippage.

Functionalities

$3

`javascript
import Exchanges from '@depay/web3-exchanges'

Exchanges.uniswap_v2

`

$3

`javascript
import Exchanges from '@depay/web3-exchanges'

Exchanges.arbitrum.uniswap_v3
`

$3

`javascript
import Exchanges from '@depay/web3-exchanges'

let routes = Exchanges.route({
blockchain: 'ethereum'
tokenIn: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
tokenOut: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
amountOutMin: 2
})
`

route can also be called on an exchange:

`javascript
import Exchanges from '@depay/web3-exchanges'

let route = await Exchanges.ethereum.uniswap_v2.route({
tokenIn: '0xa0bEd124a09ac2Bd941b10349d8d224fe3c955eb',
tokenOut: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
amountIn: 1
})
`

Development

`
yarn install
yarn dev
``