Contract

?module=contract

https://fonscan.io/api?module=contract

Get a list of contracts

listcontracts

List sorted in ascending order based on the time a contact was first indexed by the explorer. With filters `not_decompiled`(`4`) or `not_verified(4)` the results will not be sorted for performance reasons.

Example:

https://fonscan.io/api
   ?module=contract
   &action=listcontracts

Request params

Parameter	Description
page	optional nonnegative integer representing the page number used for pagination. 'offset' must also be provided.
offset	optional nonnegative integer representing the max number of records to return when paginating. 'page' must also be provided.
filter	optional string verified|decompiled|unverified|not_decompiled|empty, or 1|2|3|4|5 respectively. Returns contracts with the requested status.
not_decompiled_with_version	optional string ensures none of the returned contracts were decompiled with the provided version. Ignored unless filtering for decompiled contracts.
verified_at_start_timestamp	optional unix timestamp Represents the starting timestamp for verified contracts. Only used with verified filter.
verified_at_end_timestamp	optional unix timestamp Represents the ending timestamp for verified contracts. Only used with verified filter.

Example Result

{
  "message": "OK",
  "result": [
    {
      "ABI": "[{\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event\"\n}, {\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event2\"\n}, {\n\"type\":\"function\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\"}],\n\"name\":\"foo\",\n\"outputs\": []\n}]\n",
      "CompilerVersion": "v0.2.1-2016-01-30-91a6b35",
      "ContractName": "Test",
      "OptimizationUsed": "1",
      "SourceCode": "pragma solidity >0.4.24;\n\ncontract Test {\nconstructor() public { b = hex\"12345678901234567890123456789012\"; }\nevent Event(uint indexed a, bytes32 b);\nevent Event2(uint indexed a, bytes32 b);\nfunction foo(uint a) public { emit Event(a, b); }\nbytes32 b;\n}\n"
    }
  ],
  "status": "1"
}

Get ABI for a verified contract

getabi

Also available through a GraphQL addresses query.

Example:

https://fonscan.io/api
   ?module=contract
   &action=getabi
   &address={addressHash}

Request params

Parameter	Description
address	string containing the address hash.

Example Result

{
  "message": "OK",
  "result": "[{\"constant\":false,\"inputs\":[{\"name\":\"voucher_token\",\"type\":\"bytes32\"}],\"name\":\"burn\",\"outputs\":[{\"name\":\"success\",\"type\":\"bool\"}],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"voucher_token\",\"type\":\"bytes32\"}],\"name\":\"is_expired\",\"outputs\":[{\"name\":\"\",\"type\":\"bool\"}],\"payable\":false,\"stateMutability\":\"view\",\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"voucher_token\",\"type\":\"bytes32\"}],\"name\":\"is_burnt\",\"outputs\":[{\"name\":\"\",\"type\":\"bool\"}],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"},{\"inputs\":[{\"name\":\"voucher_token\",\"type\":\"bytes32\"},{\"name\":\"_lifetime\",\"type\":\"uint256\"}],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"constructor\"}]",
  "status": "1"
}

Get contract source code for a verified contract

getsourcecode

Also available through a GraphQL addresses query.

Example:

https://fonscan.io/api
   ?module=contract
   &action=getsourcecode
   &address={addressHash}

Request params

Parameter	Description
address	string containing the address hash.

Example Result

{
  "message": "OK",
  "result": {
    "ABI": "[{\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event\"\n}, {\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event2\"\n}, {\n\"type\":\"function\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\"}],\n\"name\":\"foo\",\n\"outputs\": []\n}]\n",
    "CompilerVersion": "v0.2.1-2016-01-30-91a6b35",
    "ContractName": "Test",
    "FileName": "{sourcify path or empty}",
    "ImplementationAddress": "0x000000000000000000000000000000000000000e",
    "IsProxy": "true",
    "OptimizationUsed": "1",
    "SourceCode": "pragma solidity >0.4.24;\n\ncontract Test {\nconstructor() public { b = hex\"12345678901234567890123456789012\"; }\nevent Event(uint indexed a, bytes32 b);\nevent Event2(uint indexed a, bytes32 b);\nfunction foo(uint a) public { emit Event(a, b); }\nbytes32 b;\n}\n"
  },
  "status": "1"
}

Verify a contract with its source code and contract creation information

verify

Example:

https://fonscan.io/api
   ?module=contract
   &action=verify
   &addressHash={addressHash}
   &name={name}
   &compilerVersion={compilerVersion}
   &optimization={false}
   &contractSourceCode={contractSourceCode}

Curl Post Example

curl -d '{"addressHash":"0xc63BB6555C90846afACaC08A0F0Aa5caFCB382a1","compilerVersion":"v0.5.4+commit.9549d8ff", "contractSourceCode":"pragma solidity ^0.5.4; contract Test { }","name":"Test","optimization":false}' -H "Content-Type: application/json" -X POST "https://blockscout.com/poa/sokol/api?module=contract&action=verify"

On successful submission you will receive a guid as a receipt. Use this with checkverifystatusto view verification status.

Request params

Parameter	Description
addressHash	string containing the address hash of the contract.
name	string containing the name of the contract.
compilerVersion	string containing the compiler version for the contract.
optimization	enum whether or not compiler optimizations were enabled 0=false, 1=true
contractSourceCode	string containing the source code of the contract.
constructorArguments	optional string constructor argument data provided.
autodetectConstructorArguments	optional boolean whether or not automatically detect constructor argument.
evmVersion	optional EVM version for the contract.
optimizationRuns	optional number of optimization runs used during compilation
library1Name	optional string name of the first library used.
library1Address	optional string address of the first library used.
library2Name	optional string name of the second library used.
library2Address	optional string address of the second library used.
library3Name	optional string name of the third library used.
library3Address	optional string address of the third library used.
library4Name	optional string name of the fourth library used.
library4Address	optional string address of the fourth library used.
library5Name	optional string name of the fifth library used.
library5Address	optional string address of the fifth library used.

Example Result

{
  "message": "OK",
  "result": {
    "ABI": "[{\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event\"\n}, {\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event2\"\n}, {\n\"type\":\"function\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\"}],\n\"name\":\"foo\",\n\"outputs\": []\n}]\n",
    "CompilerVersion": "v0.2.1-2016-01-30-91a6b35",
    "ContractName": "Test",
    "ImplementationAddress": "0x000000000000000000000000000000000000000e",
    "IsProxy": "true",
    "OptimizationUsed": "1",
    "SourceCode": "pragma solidity >0.4.24;\n\ncontract Test {\nconstructor() public { b = hex\"12345678901234567890123456789012\"; }\nevent Event(uint indexed a, bytes32 b);\nevent Event2(uint indexed a, bytes32 b);\nfunction foo(uint a) public { emit Event(a, b); }\nbytes32 b;\n}\n"
  },
  "status": "1"
}

Verify a contract through Sourcify

verify_via_sourcify

1. if a smart contract is already verified on Sourcify, it will automatically fetch the data from the repo

2. otherwise you need to upload source files and JSON metadata file(s).

Example:

https://fonscan.io/api
 ?module=contract
 &action=verify_via_sourcify
 &addressHash={addressHash}

POST body example

--6e1e4c11657c62dc1e4349d024de9e28
Content-Disposition: form-data; name="addressHash"

0xb77b7443e0F32F1FEBf0BE0fBd7124D135d0a525

--6e1e4c11657c62dc1e4349d024de9e28
Content-Disposition: form-data; name="files[0]"; filename="contract.sol"
Content-Type: application/json

...Source code...

--6e1e4c11657c62dc1e4349d024de9e28
Content-Disposition: form-data; name="files[1]"; filename="metadata.json"
Content-Type: application/json

...JSON metadata...

--6e1e4c11657c62dc1e4349d024de9e28--

Request params

Parameter	Description
addressHash	string containing the address hash.
files	array with sources and metadata files

Example Result

{
  "message": "OK",
  "result": {
    "ABI": "[{\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event\"\n}, {\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event2\"\n}, {\n\"type\":\"function\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\"}],\n\"name\":\"foo\",\n\"outputs\": []\n}]\n",
    "CompilerVersion": "v0.2.1-2016-01-30-91a6b35",
    "ContractName": "Test",
    "ImplementationAddress": "0x000000000000000000000000000000000000000e",
    "IsProxy": "true",
    "OptimizationUsed": "1",
    "SourceCode": "pragma solidity >0.4.24;\n\ncontract Test {\nconstructor() public { b = hex\"12345678901234567890123456789012\"; }\nevent Event(uint indexed a, bytes32 b);\nevent Event2(uint indexed a, bytes32 b);\nfunction foo(uint a) public { emit Event(a, b); }\nbytes32 b;\n}\n"
  },
  "status": "1"
}

Verify a vyper contract with its source code and contract creation information

verify_vyper_contract

Example

https://fonscan.io/api
 ?module=contract
 &action=verify_vyper_contract
 &addressHash={addressHash}
 &name={name}
 &compilerVersion={compilerVersion}
 &contractSourceCode={contractSourceCode}

curl POST example

curl --location --request POST 'http://localhost:4000/api?module=contract&action=verify_vyper_contract' --form 'contractSourceCode="SOURCE_CODE"' --form 'name="Vyper_contract"' --form 'addressHash="0xE60B1B8bD493569a3E945be50A6c89d29a560Fa1"' --form 'compilerVersion="v0.2.12"'

Request params

Parameter	Description
addressHash	string containing the address hash of the contract.
name	string containing the name of the contract.
compilerVersion	string containing the compiler version for the contract.
contractSourceCode	string containing the source code of the contract.
constructorArguments	string constructor argument data provided.

Example Result

{
  "message": "OK",
  "result": {
    "ABI": "[{\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event\"\n}, {\n\"type\":\"event\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\",\"indexed\":true},{\"name\":\"b\",\"type\":\"bytes32\",\"indexed\":false}],\n\"name\":\"Event2\"\n}, {\n\"type\":\"function\",\n\"inputs\": [{\"name\":\"a\",\"type\":\"uint256\"}],\n\"name\":\"foo\",\n\"outputs\": []\n}]\n",
    "CompilerVersion": "v0.2.1-2016-01-30-91a6b35",
    "ContractName": "Test",
    "ImplementationAddress": "0x000000000000000000000000000000000000000e",
    "IsProxy": "true",
    "OptimizationUsed": "1",
    "SourceCode": "pragma solidity >0.4.24;\n\ncontract Test {\nconstructor() public { b = hex\"12345678901234567890123456789012\"; }\nevent Event(uint indexed a, bytes32 b);\nevent Event2(uint indexed a, bytes32 b);\nfunction foo(uint a) public { emit Event(a, b); }\nbytes32 b;\n}\n"
  },
  "status": "1"
}

Verify a contract with Standard input JSON file

verifysourcecode

Example

https://fonscan.io/api
 ?module=contract
 &action=verifysourcecode
 &codeformat={solidity-standard-json-input}
 &contractaddress={contractaddress}
 &contractname={contractname}
 &compilerversion={compilerversion}
 &sourceCode={sourceCode}

Request params

Parameter	Description
codeformat	Format of sourceCode (currently only supports solidity-standard-json-input)
contractaddress	string containing the address hash of the contract.
contractname	string name of the contract. It an be an empty string(""), just the contract name("ContractName"), or a filename and contract name("contracts/contract_1.sol:ContractName")
compilerversion	string containing the compiler version for the contract.
sourceCode	string standard input json
constructorArguments	optional string constructor argument data provided.
autodetectConstructorArguments	optional boolean whether or not automatically detect constructor argument.

Example Result

{
  "message": "OK",
  "result": "b080b96bd06ad1c9341c2afb7e3730311388544961acde94",
  "status": "1"
}

Return status of a verification attempt

checkverifystatus

guid is received as a receipt from the verifysourcecode method.

Example

https://fonscan.io/api
 ?module=contract
 &action=checkverifystatus
 &guid={identifierString}

Request params

Parameter	Description
guid	stringused for identifying verification attempt

Example Result

{
  "message": "OK",
  "result": "Pending in queue",
  "status": "1"
}

Return Options: Pending in queue | Pass - Verified | Fail - Unable to verify | Unknown UID