Creditcoin3

A Creditcoin3 node with the Ethereum RPC support, ready for deploying smart contracts.

Generation & Upstream

This project was originally forked from the Frontier template. The template is maintained in the Frontier project repository, and can be used to generate a stand-alone template for use in an independent project via the included template generation script.

A ready-to-use template generated this way is hosted for each Frontier release on the substrate-developer-hub/frontier-node-template repository.

This template was originally forked from the Substrate Node Template. You can find more information on features on this template there, and more detailed usage on the Substrate Developer Hub Tutorials that use this heavily.

Build & Run

To build the chain, execute the following commands from the project root:

cargo build --release

To execute the chain, run:

./target/release/creditcoin3-node --dev

The node also supports to use manual seal (to produce block manually through RPC). This is also used by the ts-tests:

$ ./target/release/creditcoin3-node --dev --sealing=manual
# Or
$ ./target/release/creditcoin3-node --dev --sealing=instant

Docker Based Development

Optionally, You can build and run the frontier node within Docker directly. The Dockerfile is optimized for development speed. (Running the docker run... command will recompile the binaries but not the dependencies)

Building (takes 5-10 min):

docker build -t creditcoin3-node-dev .

Running (takes 1 min to rebuild binaries):

docker run -t creditcoin3-node-dev

Genesis Configuration

The development chain spec included with this project defines a genesis block that has been pre-configured with an EVM account for Alice. When a development chain is started, Alice's EVM account will be funded with a large amount of Ether. The Polkadot UI can be used to see the details of Alice's EVM account. In order to view an EVM account, use the Developer tab of the Polkadot UI Settings app to define the EVM Account type as below. It is also necessary to define the Address and LookupSource to send transaction, and Transaction and Signature to be able to inspect blocks:

{
  "Address": "MultiAddress",
  "LookupSource": "MultiAddress",
  "Account": {
    "nonce": "U256",
    "balance": "U256"
  },
  "Transaction": {
    "nonce": "U256",
    "action": "String",
    "gas_price": "u64",
    "gas_limit": "u64",
    "value": "U256",
    "input": "Vec<u8>",
    "signature": "Signature"
  },
  "Signature": {
    "v": "u64",
    "r": "H256",
    "s": "H256"
  }
}

Use the Developer app's RPC calls tab to query eth > getBalance(address, number) with Alice's EVM account ID (0xd43593c715fdd31c61141abd04a99fd6822c8558); the value that is returned should be:

x: eth.getBalance
340,282,366,920,938,463,463,374,607,431,768,211,455

Further reading: EVM accounts

Alice's EVM account ID was calculated using an included utility script.

Example 1: Deploy basic contract using Remix & Metamask

Adding local network to Metamask

Creditcoin3 is compatible with most tooling from the Ethereum ecosystem, including browser wallets like Metamask. To connect to your local dev node, add it as a new network:

Network name: Creditcoin3 Local
New RPC URL: http://127.0.0.1:9944
Chain ID: 42
Currency symbol: CTC
Block explorer URL: <empty>

EVM accounts

To fund an account, simply transfer from one of the dev accounts. Import the Alith account to Metamask and you should see it funded with 1M CTC.

Alith (SUDO) keys:

Address: 0xf24FF3a9CF04c71Dbc94D0b566f7A27B94566cac
Private key: 0x5fb92d6e98884f76de468fa3f6278f8807c48bebc13595d45af5bdc4da702133

Deploying contracts with Remix

We will deploy a simple Counter contract:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

contract TestCounter {
    int private count = 0;
    function incrementCounter() public {
        count += 1;
    }
    function decrementCounter() public {
        count -= 1;
    }

    function getCount() public view returns (int) {
        return count;
    }
}

1. Open the Remix IDE. In the Remix IDE, click on the Solidity tab and create a new file called Counter.sol. Paste the Counter contract in the file.

2. In the Remix IDE, click on the Deploy & Run tab. In the Environment dropdown, select Injected Web3. This will prompt you to connect to Metamask.

3. Click on Deploy and Metamask should prompt you to sign the transaction.

4. Once deployed, you can interact with the contract through the Deployed Contracts dropdown menu. Try sending transactions to increase and decrease the counter.