# 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. ```javascript 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); } } ```