Swap & Cross-Chain

Swap

Estimation

This endpoint retrieves a list of decentralized exchanges (dexes) where the selected pair can be swapped. The list is sorted by profit, so we recommend choosing the first dex in the list.

curl -X 'GET' 'https://api.crowdswap.org/api/v1/swap/estimate-all?fromToken%5Baddress%5D=0x0000000000000000000000000000000000001010&fromToken%5BchainId%5D=137&fromToken%5Bdecimals%5D=18&fromToken%5Bname%5D=Matic%20Token&fromToken%5Bsymbol%5D=MATIC&toToken%5Baddress%5D=0x483dd3425278C1f79F377f1034d9d2CaE55648B6&toToken%5BchainId%5D=137&toToken%5Bdecimals%5D=18&toToken%5Bname%5D=Crowd%20Token&toToken%5Bsymbol%5D=CROWD&amount=1000000000000000000' \
  -H 'accept: application/json'
  -H 'x-api-key: YOUR_API_KEY'

Request

Field	Description	Example
fromToken[address]	Address of source token	0x0000000000000000000000000000000000001010
fromToken[chainId]	Chain id of source token	137
fromToken[decimals]	Decimals of source token	18
fromToken[name]	Name of source token	Matic Token
fromToken[symbol]	Symbol of source token	MATIC
toToken[address]	Address of destination token	0x483dd3425278C1f79F377f1034d9d2CaE55648B6
toToken[chainId]	Chain id of destination token	137
toToken[decimals]	Decimals of destination token	18
toToken[name]	Name of destination token	Crowd Token
toToken[symbol]	Symbol of destination token	CROWD
amount	An amount of the source token to be swapped (The decimal of token must be considered in the amount)	1000000000000000000

Response

{​
  "successfulEstimationsList": [​
    {​
      "swapName": "string",​
      "delegatedDex": "string",​
      "fromToken": "string",​
      "fromTokenPrice": "string",​
      "toToken": "string",​
      "toTokenPrice": "string",​
      "amountIn": "string",​
      "amountOut": "string",​
      "minAmountOut": "string",​
      "route": "string",​
      "reserves": [​
        "string"​
      ],​
      "priceImpact": "string",​
      "poolInfo": "string",​
      "swapFee": "string",​
      "networkFee": "string",​
      "gasPrice": "string",​
      "currentDexFeePercentage": "string",​
      "crowdswapFeePercentage": "string",​
      "swapFeeInUSDT": "string",​
      "networkFeeInUSDT": "string",​
      "crowdswapFeeInUSDT": "string",​
      "totalFeeInUSDT": "string",​
      "pricePerToken": "number",​
      "cost": "number",​
      "totalPaidInUSDT": "string",​
      "totalIncomeInUSDT": "string",​
      "amountOutInUSDT": "string",​
      "amountInInUSDT": "string",​
      "amountOutPerAmountInRatio": "string",​
      "amountInPerAmountOutRatio": "string",​
      "approveAddress": "string",​
      "tradeType": "number",​
      "trade": {}​
    }​
  ]​
​}

Transaction

This endpoint returns from, to, data, value, and gasLimit, all of which needed for executing a swap.

• A dex name must be added to the url. The dex name can be found in estimation response e.g., CrowdSwapV2, Quickswap

curl -X 'GET' \
  'https://api.crowdswap.org/api/v1/swap/{dex}?fromToken%5Baddress%5D=0x0000000000000000000000000000000000001010&fromToken%5BchainId%5D=137&fromToken%5Bdecimals%5D=18&fromToken%5Bname%5D=Matic%20Token&fromToken%5Bsymbol%5D=MATIC&toToken%5Baddress%5D=0x483dd3425278C1f79F377f1034d9d2CaE55648B6&toToken%5BchainId%5D=137&toToken%5Bdecimals%5D=18&toToken%5Bname%5D=Crowd%20Token&toToken%5Bsymbol%5D=CROWD&amount=1000000000000000000&userAddress=0x000000000000000000000000000000000000000&receiverAddress=0x000000000000000000000000000000000000000' \
  -H 'accept: application/json'
  -H 'x-api-key: YOUR_API_KEY'

Request

Field	Description	Example
fromToken[address]	Address of source token	0x0000000000000000000000000000000000001010
fromToken[chainId]	Chain id of source token	137
fromToken[decimals]	Decimals of source token	18
fromToken[name]	Name of source token	Matic Token
fromToken[symbol]	Symbol of source token	MATIC
toToken[address]	Address of destination token	0x483dd3425278C1f79F377f1034d9d2CaE55648B6
toToken[chainId]	Chain id of destination token	137
toToken[decimals]	Decimals of destination token	18
toToken[name]	Name of destination token	Crowd Token
toToken[symbol]	Symbol of destination token	CROWD
amount	An amount of input tokens to swap (the entrance amount must be based on token's decimal)	1000000000000000000
userAddress	Address of the user who initiates the swap transaction	any arbitrary address
receiverAddress	Address of the recipient if it is different from the userAddress	any arbitrary address

Response

{
  "from": "string",
  "to": "string",
  "data": "string",
  "value": "string",
  "gasLimit": "string"
}

Cross-Chain

Estimation and Transaction

This endpoint finds a route with potentially the best possible outcome for the requested cross-chain pair and returns an estimation.

curl -X 'GET' \
  'https://api.crowdswap.org/api/v1/crossChainSwap/estimate-all?fromToken%5Baddress%5D=0x0000000000000000000000000000000000001010&fromToken%5BchainId%5D=137&fromToken%5Bdecimals%5D=18&fromToken%5Bname%5D=Matic%20Token&fromToken%5Bsymbol%5D=MATIC&toToken%5Baddress%5D=0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE&toToken%5BchainId%5D=56&toToken%5Bdecimals%5D=18&toToken%5Bname%5D=Binance%20Coin&toToken%5Bsymbol%5D=BNB&amountIn=1000000000000000000' \
  -H 'accept: application/json'
  -H 'x-api-key: YOUR_API_KEY'

Request

Field	Description	Example
fromToken[address]	Address of source token	0x0000000000000000000000000000000000001010
fromToken[chainId]	Chain id of source token	137
fromToken[decimals]	Decimals of source token	18
fromToken[name]	Name of source token	Matic Token
fromToken[symbol]	Symbol of source token	MATIC
toToken[address]	Address of destination token	0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE
toToken[chainId]	Chain id of destination token	56
toToken[decimals]	Decimals of destination token	18
toToken[name]	Name of destination token	Binance Coin
toToken[symbol]	Symbol of destination token	BNB
amountIn	An amount of fromToken to be swapped (The decimal of token must be considered in the amount)	1000000000000000000
userAddress	Address of the user who initiates the cross-chain swap transaction	any arbitrary address

Response

{
  "crossChainName": "string",
  "tokenIn": {
    "address": "string",
    "chainId": "number",
    "decimals": "number",
    "amount": "string",
    "symbol": "string"
  },
  "tokenOut": {
    "address": "string",
    "chainId": "number",
    "decimals": "number",
    "amount": "string",
    "symbol": "string"
  },
  "amountIn": "string",
  "amountOut": "string",
  "minAmountOut": "string",
  "approveAddress": "string",
  "status": "number",
  "msg": "string",
  "swapTx": {
    "to": "string",
    "data": "number",
    "value": "number",
    "gasLimit": "string"
  },
  "fees": {
    "token": {
      "address": "string",
      "chainId": "number",
      "decimals": "number",
      "name": "string",
      "symbol": "string"
    },
    "amount": "string",
    "type": "number"
  },
  "includedInOutputFees": {
    "token": {
      "address": "string",
      "chainId": "number",
      "decimals": "number",
      "name": "string",
      "symbol": "string"
    },
    "amount": "string",
    "type": "number"
  },
  "swapSpecData": {}
}

How to send a transaction

Both Swap and Cross-Chain APIs return the data needed for executing a transaction. The data, which named tx in below code, contains from (user address), to (contract address), data (populated data), value (coin value if needed), gasLimit. You can use below code to run your transaction.

To send a transaction, you can get tx from the response of Swap and Cross-Chain end-points.

import { ExternalProvider, Web3Provider } from '@ethersproject/providers';

export class TransactionService{
  private provider?: Web3Provider;

  constructor(){
    this.provider = new Web3Provider(provider as ExternalProvider, 'any');
  }

  function sendTransaction(tx){
    this.provider?.getSigner().sendTransaction(tx);
  }
}