Local Swap This section explains the integration and usage of various decentralized exchange (DEX) protocols for local swapping functionalities.
Step 1: Check the Allowance of the DEX on the Token Contract
To initiate a swap, first determine if the DEX has the necessary allowance to access the tokens. This can be done using the following API endpoint:
API URL : https://api.expand.network/fungibletoken/getuserallowance
Sample Request:
Copy https://api.expand.network/fungibletoken/getuserallowance?owner=0x6Fb447Ae94F5180254D436A693907a1f57696900&tokenAddress=0x6b175474e89094c44da98b954eedeac495271d0f&spender=0xBA12222222228d8Ba445958a75a0704d566BF2C8 Sample Response:
Copy {
"status" : 200 ,
"msg" : "success" ,
"data" : {
"allowance" : "999000000000000000000"
}
} Step 2: Approve the Dex from the Token Contract
If the allowance is less than the token amount to be swapped, the user must approve the DEX router from the token contract.
This can be done using the following API endpoint:
API URL : https://api.expand.network/fungibletoken/approve
Sample Request:
Copy {
"from" : "0x63056E00436Da25BcF48A40dfBbDcc7089351006" ,
"tokenAddress" : "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2" ,
"amount" : "1000000000000000000000" ,
"to" : "0x828b154032950c8ff7cf8085d841723db2696056" ,
"gas" : "100000" ,
"chainId" : "1"
} Sample Response:
Copy {
"status" : 200 ,
"msg" : "success" ,
"data" : {
"from" : "0x63056E00436Da25BcF48A40dfBbDcc7089351006" ,
"to" : "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2" ,
"value" : "0" ,
"gas" : "100000" ,
"data": "0x095ea7b3000000000000000000000000828b154032950c8ff7cf8085d841723db269605600000000000000000000000000000000000000000000003635c9adc5dea00000"
}
} Step 3: Swap the tokens
After the successful approval, we can do the swap. User can swap the tokens on their preferred Dex by changing the "dexId
API URL : https://api.expand.network/dex/swap
Sample Request:
Copy {
"dexId" : "1000" ,
"amountIn" : "1000000000000000" ,
"amountOutMin" : "0" ,
"path" : [ "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2" , "0x6B175474E89094C44Da98b954EedeAC495271d0F" ] ,
"to" : "0x63056E00436Da25BcF48A40dfBbDcc7089351006" ,
"deadline" : "1665990894" ,
"from" : "0x63056E00436Da25BcF48A40dfBbDcc7089351006" ,
"gas" : "173376"
} Sample Response:
Copy {
"status" : 200 ,
"msg" : "success" ,
"data" : {
"from" : "0x63056E00436Da25BcF48A40dfBbDcc7089351006" ,
"to" : "0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D" ,
"value" : "0" ,
"gas" : "173376" ,
"data": "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"
}
} 