Blockscout smart-contract verification API

Blockscout also offers a contract verification API.

This is the preferred option for contract verification via API. However, you can also use RPC endpoints, more info is available here.

License type

You can specify license type of the smart contract as string or number. For example for GNU General Public License v2.0 (GNU GPLv2) you could pass either 4 or "gnu_gpl_v2"

We are supporting such types of license as:

1. No License (None)
2. The Unlicense (Unlicense)
3. MIT License (MIT)
4. GNU General Public License v2.0 (GNU GPLv2)
5. GNU General Public License v3.0 (GNU GPLv3)
6. GNU Lesser General Public License v2.1 (GNU LGPLv2.1)
7. GNU Lesser General Public License v3.0 (GNU LGPLv3)
8. BSD 2-clause "Simplified" license (BSD-2-Clause)
9. BSD 3-clause "New" Or "Revised" license* (BSD-3-Clause)
10. Mozilla Public License 2.0 (MPL-2.0)
11. Open Software License 3.0 (OSL-3.0)
12. Apache 2.0 (Apache-2.0)
13. GNU Affero General Public License (GNU AGPLv3)
14. Business Source License (BSL 1.1)

API license types:

none
unlicense
mit
gnu_gpl_v2
gnu_gpl_v3
gnu_lgpl_v2_1
gnu_lgpl_v3
bsd_2_clause
bsd_3_clause
mpl_2_0
osl_3_0
apache_2_0
gnu_agpl_v3
bsl_1_1

Verify smart contract

Use the appropriate Blockscout instance endpoint to verify if the smart contract microservice is enabled.

In the following examples we use https://eth.blockscout.com to query Ethereum.

verification service running

get

Responses

application/json

cURL

JavaScript

Python

HTTP

curl -L \
  --url 'https://eth.blockscout.com/api/v2/smart-contracts/verification/config'

200

No body

Successful response

0x contract addresses in POST example urls below should be replaced with your contract hash supplied on contract creation. Variables in the body are examples and should be replaced with your contract details.

Flattened contract

For more information on parameters to pass, see the flattened source code information on the Verifying a smart contract page.

verification flattened contract

post

Body

objectoptional

Example:

{"compiler_version":"v0.8.17+commit.8df45f5f","license_type":"mit","source_code":"// SPDX-License-Identifier: GPL-3.0\n\npragma solidity >=0.7.0 <0.9.0;\n\n/**\n * @title Owner\n * @dev Set & change owner\n */\ncontract Owner {\n\n    address private owner;\n    \n    // event for EVM logging 2345678ewqwertyui54567890987654345678\n    event OwnerSet(address indexed oldOwner, address indexed newOwner);\n    \n    // modifier to check if caller is owner\n    modifier isOwner() {\n        // If the first argument of 'require' evaluates to 'false', execution terminates and all\n        // changes to the state and to Ether balances are reverted.\n        // This used to consume all gas in old EVM versions, but not anymore.\n        // It is often a good idea to use 'require' to check if functions are called correctly.\n        // As a second argument, you can also provide an explanation about what went wrong.\n        require(msg.sender == owner, \"Caller is not owner\");\n        _;\n    }\n    \n    /**\n     * @dev Set contract deployer as owner\n     */\n    constructor(uint112 abc, address abb, bytes32 ghnc) {\n        // console.log(\"Owner contract deployed by:\", msg.sender);\n        owner = msg.sender; // 'msg.sender' is sender of current call, contract deployer for a constructor\n        emit OwnerSet(address(0), owner);\n    }\n\n    /**\n     * @dev Change owner\n     * @param newOwner address of new owner\n     */\n    function changeOwner(address newOwner) public isOwner {\n        emit OwnerSet(owner, newOwner);\n        owner = newOwner;\n    }\n\n    /**\n     * @dev Return owner address \n     * @return address of owner\n     */\n    function getOwner() external view returns (address) {\n        return owner;\n    }\n}","is_optimization_enabled":true,"optimization_runs":199,"contract_name":"Owner","libraries":{"Libcheck":"0x030f7c7dbd472864220bcf9e37ede1b8a3125970","Libcheck_1":"0x030f7c7dbd472864220bcf9e37ede1b8a3125970"},"evm_version":"berlin","autodetect_constructor_args":true}

Responses

application/json

cURL

JavaScript

Python

HTTP

curl -L \
  --request POST \
  --url 'https://eth.blockscout.com/api/v2/smart-contracts/0xb12cad649a56e67188bbaa56583c18dc7d2812ed/verification/via/flattened-code' \
  --header 'Content-Type: application/json' \
  --data '{
    "compiler_version": "v0.8.17+commit.8df45f5f",
    "license_type": "mit",
    "source_code": "// SPDX-License-Identifier: GPL-3.0

  pragma solidity >=0.7.0 <0.9.0;

  /**
   * @title Owner
   * @dev Set & change owner
   */
  contract Owner {

      address private owner;
      
      // event for EVM logging 2345678ewqwertyui54567890987654345678
      event OwnerSet(address indexed oldOwner, address indexed newOwner);
      
      // modifier to check if caller is owner
      modifier isOwner() {
          // If the first argument of 'require' evaluates to 'false', execution terminates and all
          // changes to the state and to Ether balances are reverted.
          // This used to consume all gas in old EVM versions, but not anymore.
          // It is often a good idea to use 'require' to check if functions are called correctly.
          // As a second argument, you can also provide an explanation about what went wrong.
          require(msg.sender == owner, \"Caller is not owner\");
          _;
      }
      
      /**
       * @dev Set contract deployer as owner
       */
      constructor(uint112 abc, address abb, bytes32 ghnc) {
          // console.log(\"Owner contract deployed by:\", msg.sender);
          owner = msg.sender; // 'msg.sender' is sender of current call, contract deployer for a constructor
          emit OwnerSet(address(0), owner);
      }

      /**
       * @dev Change owner
       * @param newOwner address of new owner
       */
      function changeOwner(address newOwner) public isOwner {
          emit OwnerSet(owner, newOwner);
          owner = newOwner;
      }

      /**
       * @dev Return owner address 
       * @return address of owner
       */
      function getOwner() external view returns (address) {
          return owner;
      }
  }",
    "is_optimization_enabled": true,
    "optimization_runs": 199,
    "contract_name": "Owner",
    "libraries": {
      "Libcheck": "0x030f7c7dbd472864220bcf9e37ede1b8a3125970",
      "Libcheck_1": "0x030f7c7dbd472864220bcf9e37ede1b8a3125970"
    },
    "evm_version": "berlin",
    "autodetect_constructor_args": true
  }'

200

No body

Successful response

Via Standard JSON input

For more information on parameters to pass, see the flattened source code information on the Verifying a smart contract page. 0x contract in POST example should be replaced with your contract hash.

verification standard json

post

Body

compiler_versionnumberoptional

Example: v0.8.17+commit.8df45f5f

contract_namestringoptional

Example: Owner

files[0]string · binaryoptional

autodetect_constructor_argsbooleanoptional

Example: false

constructor_argsstringoptional

Example:

00000000000000000000000000000000000000000000000000000002d2982db3000000000000000000000000bb36c792b9b45aaf8b848a1392b0d6559202729e666f6f0000000000000000000000000000000000000000000000000000000000

license_typestringoptional

Example: gnu_gpl_v2

Responses

application/json

cURL

JavaScript

Python

HTTP

curl -L \
  --request POST \
  --url 'https://eth.blockscout.com/api/v2/smart-contracts/0x9c1c619176b4f8521a0ab166945d785b92aef453/verification/via/standard-input' \
  --header 'Content-Type: multipart/form-data' \
  --form 'compiler_version=v0.8.17+commit.8df45f5f' \
  --form 'contract_name=Owner' \
  --form 'files[0]=binary' \
  --form 'autodetect_constructor_args=false' \
  --form 'constructor_args=00000000000000000000000000000000000000000000000000000002d2982db3000000000000000000000000bb36c792b9b45aaf8b848a1392b0d6559202729e666f6f0000000000000000000000000000000000000000000000000000000000' \
  --form 'license_type=gnu_gpl_v2'

200

No body

Successful response

Via Sourcify Files

For more information on parameters to pass, see the Contract Verification via Sourcify. 0x contract in POST example url should be replaced with your contract hash, as should your relevant variables.

verification sourcify

post

Body

files[0]stringoptional

chosen_contract_indexintegeroptional

Example: 4

Responses

application/json

cURL

JavaScript

Python

HTTP

curl -L \
  --request POST \
  --url 'https://eth.blockscout.com/api/v2/smart-contracts/0x030f7c7dbd472864220bcf9e37ede1b8a3125970/verification/via/sourcify' \
  --header 'Content-Type: multipart/form-data' \
  --form 'files[0]=text' \
  --form 'chosen_contract_index=4'

200

No body

Successful response

Multi-part Solidity files

verification multipart Copy

post

Body

compiler_versionnumberoptional

Example: v0.8.17+commit.8df45f5f

license_typestringoptional

Example: gnu_gpl_v3

is_optimization_enabledbooleanoptional

Example: true

librariesstringoptional

Example: {"Libcheck": "0x030f7c7dbd472864220bcf9e37ede1b8a3125970"}

evm_versionstringoptional

Example: london

optimization_runsintegeroptional

Example: 199

files[0]stringoptional

files[1]string · binaryoptional

Responses

application/json

cURL

JavaScript

Python

HTTP

curl -L \
  --request POST \
  --url 'https://eth.blockscout.com/api/v2/smart-contracts/0x030f7c7dbd472864220bcf9e37ede1b8a3125970/verification/via/multi-part' \
  --header 'Content-Type: multipart/form-data' \
  --form 'compiler_version=v0.8.17+commit.8df45f5f' \
  --form 'license_type=gnu_gpl_v3' \
  --form 'is_optimization_enabled=true' \
  --form 'libraries={"Libcheck": "0x030f7c7dbd472864220bcf9e37ede1b8a3125970"}' \
  --form 'evm_version=london' \
  --form 'optimization_runs=199' \
  --form 'files[0]=text' \
  --form 'files[1]=binary'

200

No body

Successful response

Vyper Contracts

verification vyper contract

post

Body

objectoptional

Example:

{"compiler_version":"v0.2.12+commit.2c6842c","license_type":"gnu_agpl_v3","source_code":"from vyper.interfaces import ERC20\n\nimplements: ERC20\n\nevent Transfer:\n    sender: indexed(address)\n    receiver: indexed(address)\n    value: uint256\n\nevent Approval:\n    owner: indexed(address)\n    spender: indexed(address)\n    value: uint256\n\nname: public(String[64])\nsymbol: public(String[32])\ndecimals: public(uint256)\n\nbalanceOf: public(HashMap[address, uint256])\nallowance: public(HashMap[address, HashMap[address, uint256]])\ntotalSupply: public(uint256)\nminter: address\n_supply: uint256\n_check: uint256 #1% of the total supply check\n\n\n@external\ndef __init__():\n    self._supply = 10_000_000_000 \n    self._check = 100_000_000\n    self.decimals = 18\n    self.name = 'Kooopa'\n    self.symbol = 'KOO'\n    \n    init_supply: uint256 = self._supply * 10 ** self.decimals\n    \n    self.balanceOf[msg.sender] = init_supply\n    self.totalSupply = init_supply\n    self.minter = msg.sender\n\n    log Transfer(ZERO_ADDRESS, msg.sender, init_supply)\n\n\n@internal\ndef _transfer(_from : address, _to : address, _value : uint256) -> bool:\n    assert _value <= self._check, 'Transfer limit of 1%(100 Million) Tokens'\n\n    TargetBalance: uint256 = self.balanceOf[_to] + _value\n    assert TargetBalance <= self._check, 'Single wallet cannot hold more than 1%(100 Million) Tokens'\n\n    self.balanceOf[_from] -= _value\n    self.balanceOf[_to] += _value\n    log Transfer(_from, _to, _value)\n    return True\n\n\n@external\ndef transfer(_to : address, _value : uint256) -> bool:\n    self._transfer(msg.sender, _to, _value)\n    return True\n\n\n@external\ndef transferFrom(_from : address, _to : address, _value : uint256) -> bool:\n    self._transfer(_from, _to, _value)\n    self.allowance[_from][msg.sender] -= _value\n    return True\n\n\n@external\ndef approve(_spender : address, _value : uint256) -> bool:\n    assert _value <= self._check, 'Cant Approve more than 1%(100 Million) Tokens for transfer'\n\n    self.allowance[msg.sender][_spender] = _value\n    log Approval(msg.sender, _spender, _value)\n    return True\n\n\n@external\ndef mint(_to: address, _value: uint256):\n    assert msg.sender == self.minter\n    assert _to != ZERO_ADDRESS\n    self.totalSupply += _value\n    self.balanceOf[_to] += _value\n    log Transfer(ZERO_ADDRESS, _to, _value)\n\n\n@internal\ndef _burn(_to: address, _value: uint256):\n    \n    assert _to != ZERO_ADDRESS\n    self.totalSupply -= _value\n    self.balanceOf[_to] -= _value\n    log Transfer(_to, ZERO_ADDRESS, _value)\n\n\n@external\ndef burn(_value: uint256):\n    self._burn(msg.sender, _value)\n\n\n@external\ndef burnFrom(_to: address, _value: uint256):\n    self.allowance[_to][msg.sender] -= _value\n    self._burn(_to, _value)","constructor_args":null,"contract_name":"Storage","evm_version":"istanbul"}

Responses

application/json

cURL

JavaScript

Python

HTTP

curl -L \
  --request POST \
  --url 'https://eth.blockscout.com/api/v2/smart-contracts/0xd73249995040f04cb891bdf0f997579ee3a6676c/verification/via/vyper-code' \
  --header 'Content-Type: application/json' \
  --data '{
    "compiler_version": "v0.2.12+commit.2c6842c",
    "license_type": "gnu_agpl_v3",
    "source_code": "from vyper.interfaces import ERC20

  implements: ERC20

  event Transfer:
      sender: indexed(address)
      receiver: indexed(address)
      value: uint256

  event Approval:
      owner: indexed(address)
      spender: indexed(address)
      value: uint256

  name: public(String[64])
  symbol: public(String[32])
  decimals: public(uint256)

  balanceOf: public(HashMap[address, uint256])
  allowance: public(HashMap[address, HashMap[address, uint256]])
  totalSupply: public(uint256)
  minter: address
  _supply: uint256
  _check: uint256 #1% of the total supply check


  @external
  def __init__():
      self._supply = 10_000_000_000 
      self._check = 100_000_000
      self.decimals = 18
      self.name = 'Kooopa'
      self.symbol = 'KOO'
      
      init_supply: uint256 = self._supply * 10 ** self.decimals
      
      self.balanceOf[msg.sender] = init_supply
      self.totalSupply = init_supply
      self.minter = msg.sender

      log Transfer(ZERO_ADDRESS, msg.sender, init_supply)


  @internal
  def _transfer(_from : address, _to : address, _value : uint256) -> bool:
      assert _value <= self._check, 'Transfer limit of 1%(100 Million) Tokens'

      TargetBalance: uint256 = self.balanceOf[_to] + _value
      assert TargetBalance <= self._check, 'Single wallet cannot hold more than 1%(100 Million) Tokens'

      self.balanceOf[_from] -= _value
      self.balanceOf[_to] += _value
      log Transfer(_from, _to, _value)
      return True


  @external
  def transfer(_to : address, _value : uint256) -> bool:
      self._transfer(msg.sender, _to, _value)
      return True


  @external
  def transferFrom(_from : address, _to : address, _value : uint256) -> bool:
      self._transfer(_from, _to, _value)
      self.allowance[_from][msg.sender] -= _value
      return True


  @external
  def approve(_spender : address, _value : uint256) -> bool:
      assert _value <= self._check, 'Cant Approve more than 1%(100 Million) Tokens for transfer'

      self.allowance[msg.sender][_spender] = _value
      log Approval(msg.sender, _spender, _value)
      return True


  @external
  def mint(_to: address, _value: uint256):
      assert msg.sender == self.minter
      assert _to != ZERO_ADDRESS
      self.totalSupply += _value
      self.balanceOf[_to] += _value
      log Transfer(ZERO_ADDRESS, _to, _value)


  @internal
  def _burn(_to: address, _value: uint256):
      
      assert _to != ZERO_ADDRESS
      self.totalSupply -= _value
      self.balanceOf[_to] -= _value
      log Transfer(_to, ZERO_ADDRESS, _value)


  @external
  def burn(_value: uint256):
      self._burn(msg.sender, _value)


  @external
  def burnFrom(_to: address, _value: uint256):
      self.allowance[_to][msg.sender] -= _value
      self._burn(_to, _value)",
    "constructor_args": null,
    "contract_name": "Storage",
    "evm_version": "istanbul"
  }'

200

No body

Successful response

Vyper Multi-part files

verification multipart vyper

post

Body

compiler_versionnumberoptional

Example: v0.3.7+commit.6020b8bb

license_typestringoptional

Example: gnu_lgpl_v2_1

evm_versionstringoptional

Example: istanbul

files[0]string · binaryoptional

files[1]string · binaryoptional

interfaces[0]string · binaryoptional

interfaces[1]string · binaryoptional

interfaces[2]string · binaryoptional

Responses

application/json

cURL

JavaScript

Python

HTTP

curl -L \
  --request POST \
  --url 'https://eth.blockscout.com/api/v2/smart-contracts/0xc3fd3c09d5481f4d6c85e70775804de4c93fe630/verification/via/vyper-multi-part' \
  --header 'Content-Type: multipart/form-data' \
  --form 'compiler_version=v0.3.7+commit.6020b8bb' \
  --form 'license_type=gnu_lgpl_v2_1' \
  --form 'evm_version=istanbul' \
  --form 'files[0]=binary' \
  --form 'files[1]=binary' \
  --form 'interfaces[0]=binary' \
  --form 'interfaces[1]=binary' \
  --form 'interfaces[2]=binary'

200

No body

Successful response

Vyper Standard JSON input

verification standard json vyper

post

Body

compiler_versionnumberoptional

Example: v0.2.7+commit.0b3f3b3

license_typestringoptional

Example: gnu_lgpl_v3

evm_versionstringoptional

Example: istanbul

files[0]string · binaryoptional

files[1]string · binaryoptional

Responses

application/json

cURL

JavaScript

Python

HTTP

curl -L \
  --request POST \
  --url 'https://eth.blockscout.com/api/v2/smart-contracts/0xc3fd3c09d5481f4d6c85e70775804de4c93fe630/verification/via/vyper-standard-input' \
  --header 'Content-Type: multipart/form-data' \
  --form 'compiler_version=v0.2.7+commit.0b3f3b3' \
  --form 'license_type=gnu_lgpl_v3' \
  --form 'evm_version=istanbul' \
  --form 'files[0]=binary' \
  --form 'files[1]=binary'

200

No body

Successful response

Last updated 7 months ago

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