Verify Contracts in BlockScout

Contract verification exposed ABI methods needed to transfer tokens

To invoke contract methods which approve and initiate token transfers, it is important to verify the newly deployed contracts. This provides access to the ABI code.

We will verify the following group of deployed contracts for this demo. You will use your own contract address output to verify your contracts.

Sokol
[ Home ] homeMediator: 0xF190e4EBAF15E66869A3D8252AC48588a75EEf4e
[ Home ] simpleKittyCore: 0x8eb75AD1ab50aB28E78B62fEeDD9EBcF9F040E33

Kovan
[ Foreign ] foreignMediator: 0x510D85CfB9E50b60700a02AAeD789B1A5Ebe6873
[ Foreign ] kittyCore: 0x9d0c70Bfd1770B7cfbC97AfA8cF1CFcE9659271E

1) Flatten Contracts

Check that you are in the root directory from deployment steps (cryptokitties-xdai-demo ) and run the flatten command.

yarn flatten

flattened contracts will be created in the flats folder.

2) Go to Deployed KittyCore Contract in BlockScout - Kovan

• Example url: https://blockscout.com/eth/kovan/address/0x13AC5C6338796a31A39e74D70B0153C1bE5f53B4/transactions. You will replace with your [ Foreign ] kittyCore: 0x....... address.

• Click on the Code tab, then click the Verify and publish button.

In Code tab you will see the Contract Byte Code. Click Verify & Publish

3) Enter KittyCore Contract Details

• Contract Address: Preselected

• Contract Name: KittyCore

• Compiler: v0.4.24+commit.e67f0147

• EVM Version: byzantium

• Optimization: Yes

• Optimization runs: 200

• Enter the Solidity Contract code: copy code from cryptokitties-xdai-demo/flats/kitty/KittyCore_flat.sol

• ABI-encoded Constructor Arguments: leave blank

Click Verify & publish.

Verification parameters are located in the truffle-config file in the root directory. https://github.com/poanetwork/cryptokitties-xdai-demo/blob/master/truffle-config.js#L83-L94

Enter in Contract Details and click Verify & publish

On success, you will see the verified contract. It will include the contract name under details, along with a ✅ next to the code tab and the ability to Read the Contract.

Verified Contract Example. Note the ability to copy the ABI has been added.

4) Go to Deployed ForeignMediator Proxy Contract in BlockScout - Kovan

• Example url: https://blockscout.com/eth/kovan/address/0x510D85CfB9E50b60700a02AAeD789B1A5Ebe6873/transactions . You will replace with your [ Foreign ] foreignMediator: 0x....... address.

• Click on the Code tab, then click the Verify and Publish button.

5) Enter Mediator Proxy Contract Details

Mediator contracts are actually proxy contracts - so you will verify the flatted proxy contract located at: cryptokitties-xdai-demo/flats/upgradeability/EternalStorageProxy_flat.sol

• Contract Address: Preselected

• Contract Name: EternalStorageProxy

• Compiler: v0.4.24+commit.e67f0147

• EVM Version: byzantium

• Optimization: Yes

• Optimization runs: 200

• Enter the Solidity Contract code: copy code from

  cryptokitties-xdai-demo/flats/upgradeability/EternalStorageProxy_flat.sol

• ABI-encoded Constructor Arguments: leave blank

Click Verify & publish

On success, you will see the verified contract. It will include the contract name under details, along with a ✅ next to the code tab and the ability to Read the Contract.

6) Locate and Verify Additional ForeignMediator Contract

Because the previous contract is a proxy contract, you must also find the ForeignMediator contract as well to verify.

1) After the EternalStorageProxy contract has been verified, go to the Read Contract Tab 2) You will see a 2. implementation -> 0x..... row. Click on that implementation address.

Click on the implementation address

7) Verify ForeignMediator Contract

• Click on the Code tab, then click the Verify and Publish button

Verification Details

• Contract Address: Preselected

• Contract Name: ForeignMediator

• Compiler: v0.4.24+commit.e67f0147

• EVM Version: byzantium

• Optimization: Yes

• Optimization runs: 200

• Enter the Solidity Contract code: copy code from

  cryptokitties-xdai-demo/flats/mediator/ForeignMediator_flat.sol

• ABI-encoded Constructor Arguments: leave blank

Click Verify & publish

On success, you will see the verified contract. It will include the contract name under details, along with a ✅ next to the code tab and the ability to Read the Contract.

8) Verify Remaining Contracts in Sokol

You will now follow the same steps to verify the contracts on the Sokol Testnet https://blockscout.com/poa/sokol

SimpleKittyCore Parameters

• Contract Address: Preselected

• Contract Name: SimpleBridgeKitty

• Compiler: v0.4.24+commit.e67f0147

• EVM Version: byzantium

• Optimization: Yes

• Optimization runs: 200

• Enter the Solidity Contract code: copy code from cryptokitties-xdai-demo/flats/simpleKitty/SimpleBridgeKitty_flat.sol

• ABI-encoded Constructor Arguments: leave blank

Mediator Proxy Contract Parameters

We use the same proxy contract on both chains.

• Contract Address: Preselected

• Contract Name: EternalStorageProxy

• Compiler: v0.4.24+commit.e67f0147

• EVM Version: byzantium

• Optimization: Yes

• Optimization runs: 200

• Enter the Solidity Contract code: copy code from

  cryptokitties-xdai-demo/flats/upgradeability/EternalStorageProxy_flat.sol

• ABI-encoded Constructor Arguments: leave blank

HomeMediator Parameters

• Contract Address: Preselected

• Contract Name: HomeMediator

• Compiler: v0.4.24+commit.e67f0147

• EVM Version: byzantium

• Optimization: Yes

• Optimization runs: 200

• Enter the Solidity Contract code: copy code from

  cryptokitties-xdai-demo/flats/mediator/HomeMediator_flat.sol

• ABI-encoded Constructor Arguments: leave blank

9) Proceed to Transfer Operations

Once contracts are verified, methods are exposed to NiftyWallet or MEW. You can proceed to either of these tutorials, or view your Kitties in BlockScout.