Contracts

Get Contract ABI for Verified Contract Source Codes

Returns the Contract Application Binary Interface ( ABI ) of a verified smart contract.

Find verified contracts on our Verified Contracts Source Code page.

https://api-sepolia.basescan.org/api
   ?module=contract
   &action=getabi
   &address=0x8ABB13360b87Be5EEb1B98647A016adD927a136c
   &apikey=YourApiKeyToken

Try this endpoint in your browser 🔗

Query Parameters

ParameterDescription

address

the contract address that has a verified source code

A simple sample for retrieving the contractABI using Web3.js and Jquery to interact with a contract.

var Web3 = require('web3');
var web3 = new Web3(new Web3.providers.HttpProvider());
var version = web3.version.api;
        
$.getJSON('https://api-sepolia.basescan.org/api?module=contract&action=getabi&address=0x5f1E80Bf0817046fe53d73CaaC0EcC754d66aF50&apikey=YourApiKeyToken', function (data) {
    var contractABI = "";
    contractABI = JSON.parse(data.result);
    if (contractABI != ''){
        var MyContract = web3.eth.contract(contractABI);
        var myContractInstance = MyContract.at("0x5f1E80Bf0817046fe53d73CaaC0EcC754d66aF50");
        var result = myContractInstance.memberId("0x5f1E80Bf0817046fe53d73CaaC0EcC754d66aF50");
        console.log("result1 : " + result);            
        var result = myContractInstance.members(1);
        console.log("result2 : " + result);
    } else {
        console.log("Error" );
    }            
});

Get Contract Source Code for Verified Contract Source Codes

Returns the Solidity source code of a verified smart contract.

📩 Tip : You can also download a CSV list of verified contracts addresses of which the code publishers have provided a corresponding Open Source license for redistribution.

https://api-sepolia.basescan.org/api
   ?module=contract
   &action=getsourcecode
   &address=0x8ABB13360b87Be5EEb1B98647A016adD927a136c
   &apikey=YourApiKeyToken 

Try this endpoint in your browser 🔗

Query Parameters

ParameterDescription

address

the contract address that has a verified source code

Verify Source Code

Submits a contract source code to Sepolia BaseScan for verification.

  1. Requires a valid Sepolia BaseScan API key, it will be rejected otherwise

  2. Only supports HTTP POST due to max transfer size limitations for HTTP GET

  3. Supports up to 10 different library pairs

  4. Contracts that use "imports" will need to have the code concatenated into one file as we do not support "imports" in separate files.

  5. List of supported solc versions, only solc version v0.4.11 and above is supported e.g. v0.4.25+commit.59dbf8f1

  6. Upon successful submission you will receive a GUID (50 characters) as a receipt

  7. You may use this GUID to track the status of your submission

  8. Verified Source Codes will be displayed at the Verified Contracts page.

Source Code Submission Gist

👇 Note: Upon successful submission, a GUID is returned, which can be used to check for submission status.

//Submit Source Code for Verification
$.ajax({
    type: "POST", //Only POST supported  
    url: "//api-sepolia.etherscan.io/api", //Set to the  correct API url for Other Networks
    data: {
        apikey: $('#apikey').val(),                     //A valid API-Key is required        
        module: 'contract',                             //Do not change
        action: 'verifysourcecode',                     //Do not change
        contractaddress: $('#contractaddress').val(),   //Contract Address starts with 0x...     
        sourceCode: $('#sourceCode').val(),             //Contract Source Code (Flattened if necessary)
        codeformat: $('#codeformat').val(),             //solidity-single-file (default) or solidity-standard-json-input (for std-input-json-format support
        contractname: $('#contractname').val(),         //ContractName (if codeformat=solidity-standard-json-input, then enter contractname as ex: erc20.sol:erc20)
        compilerversion: $('#compilerversion').val(),   // see https://sepolia.basescan.org/solcversions for list of support versions
        optimizationUsed: $('#optimizationUsed').val(), //0 = No Optimization, 1 = Optimization used (applicable when codeformat=solidity-single-file)
        runs: 200,                                      //set to 200 as default unless otherwise  (applicable when codeformat=solidity-single-file)        
        constructorArguements: $('#constructorArguements').val(),   //if applicable
        evmversion: $('#evmVersion').val(),             //leave blank for compiler default, homestead, tangerineWhistle, spuriousDragon, byzantium, constantinople, petersburg, istanbul (applicable when codeformat=solidity-single-file)
        licenseType: $('#licenseType').val(),           //Valid codes 1-12 where 1=No License .. 12=Apache 2.0, see https://sepolia.basescan.org/contract-license-types
        libraryname1: $('#libraryname1').val(),         //if applicable, a matching pair with libraryaddress1 required
        libraryaddress1: $('#libraryaddress1').val(),   //if applicable, a matching pair with libraryname1 required
        libraryname2: $('#libraryname2').val(),         //if applicable, matching pair required
        libraryaddress2: $('#libraryaddress2').val(),   //if applicable, matching pair required
        libraryname3: $('#libraryname3').val(),         //if applicable, matching pair required
        libraryaddress3: $('#libraryaddress3').val(),   //if applicable, matching pair required
        libraryname4: $('#libraryname4').val(),         //if applicable, matching pair required
        libraryaddress4: $('#libraryaddress4').val(),   //if applicable, matching pair required
        libraryname5: $('#libraryname5').val(),         //if applicable, matching pair required
        libraryaddress5: $('#libraryaddress5').val(),   //if applicable, matching pair required
        libraryname6: $('#libraryname6').val(),         //if applicable, matching pair required
        libraryaddress6: $('#libraryaddress6').val(),   //if applicable, matching pair required
        libraryname7: $('#libraryname7').val(),         //if applicable, matching pair required
        libraryaddress7: $('#libraryaddress7').val(),   //if applicable, matching pair required
        libraryname8: $('#libraryname8').val(),         //if applicable, matching pair required
        libraryaddress8: $('#libraryaddress8').val(),   //if applicable, matching pair required
        libraryname9: $('#libraryname9').val(),         //if applicable, matching pair required
        libraryaddress9: $('#libraryaddress9').val(),   //if applicable, matching pair required
        libraryname10: $('#libraryname10').val(),       //if applicable, matching pair required
        libraryaddress10: $('#libraryaddress10').val()  //if applicable, matching pair required
    },
    success: function (result) {
        console.log(result);
        if (result.status == "1") {
            //1 = submission success, use the guid returned (result.result) to check the status of your submission.
            // Average time of processing is 30-60 seconds
            document.getElementById("postresult").innerHTML = result.status + ";" + result.message + ";" + result.result;
            // result.result is the GUID receipt for the submission, you can use this guid for checking the verification status
        } else {
            //0 = error
            document.getElementById("postresult").innerHTML = result.status + ";" + result.message + ";" + result.result;
        }
        console.log("status : " + result.status);
        console.log("result : " + result.result);
    },
    error: function (result) {
        console.log("error!");
        document.getElementById("postresult").innerHTML = "Unexpected Error"
    }
});

Check Source Code Verification Submission Status

//Check Source Code Verification Status
$.ajax({
    type: "GET",
    url: "//api-sepolia.etherscan.io/api",
    data: {
        apikey: $('#apikey').val(), 
        guid: 'ezq878u486pzijkvvmerl6a9mzwhv6sefgvqi5tkwceejc7tvn', //Replace with your Source Code GUID receipt above
        module: "contract",
        action: "checkverifystatus"
    },
    success: function (result) {
        console.log("status : " + result.status);   //0=Error, 1=Pass 
        console.log("message : " + result.message); //OK, NOTOK
        console.log("result : " + result.result);   //result explanation
        $('#guidstatus').html(">> " + result.result);
    },
    error: function (result) {
        alert('error');
    }
});

Verify Proxy Contract

Submits a proxy contract source code to Sepolia BaseScan for verification.

  1. Requires a valid Sepolia BaseScan API key, it will be rejected otherwise

  2. Current daily limit of 100 submissions per day per user (subject to change)

  3. Only supports HTTP post

  4. Upon successful submission you will receive a GUID (50 characters) as a receipt

  5. You may use this GUID to track the status of your submission

  6. Verified proxy contracts will display the "Read/Write as Proxy" of the implementation contract under the contract address's contract tab

Verifying Proxy Contract using cURL

// example with only the mandatory contract address parameter
curl -d "address=0xcbdcd3815b5f975e1a2c944a9b2cd1c985a1cb7f" "https://api-sepolia.basescan.org/api?module=contract&action=verifyproxycontract&apikey=YourApiKeyToken"

// example using the expectedimplementation optional parameter
// the expectedimplementation enforces a check to ensure the returned implementation contract address == address picked up by the verifier
curl -d "address=0xbc46363a7669f6e12353fa95bb067aead3675c29&expectedimplementation=0xe45a5176bc0f2c1198e2451c4e4501d4ed9b65a6" "https://api-sepolia.basescan.org/api?module=contract&action=verifyproxycontract&apikey=YourApiKeyToken"

Checking Proxy Contract Verification Submission Status using cURL

curl "https://api-sepolia.basescan.org/api?module=contract&action=checkproxyverification&guid=gwgrrnfy56zf6vc1fljuejwg6pelnc5yns6fg6y2i6zfpgzquz&apikey=YourApiKeyToken"

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