This code shows how to interact with Ethereum using the web3 JavaScript library:
- How to connect to an Ethereum node using RPC and the web3 library
- How to compile a Solidity smart contract from source
- How to deploy the compiled contract, signing the deploy transaction using a private key
- How to invoke read-only methods on the smart contract
- How to modify the state of the smart contract by submitting a transaction signed using a private key
This code was written for educational purposes only. Use it at your own risk! It has only been tested on the rinkeby test network.
Install a local geth node. E.g. by following: https://github.com/ethereum/go-ethereum/wiki/Installation-Instructions-for-Mac
Launch the local geth node (connecting to the rinkeby test network) in a terminal using:
geth --rinkeby --rpc --verbosity 2 console
You may need to wait for the node to synchronize with the network.
Then create your test account by using the geth REPL:
personal.newAccount()
eth.coinbase
You will then have to request some Ether for your account using the faucet service at https://faucet.rinkeby.io by pasing a URL to a Tweet containing the Ethereum address you created above.
You will also need to grab a random destination Ethereum account. You can use https://rinkeby.etherscan.io to check the status of your account or to find the address of a random Ethereum account.
Install dependencies:
npm install
You can launch the client and get help using:
node ./lib/client.js --help
E.g.
dselman$ node ./lib/client.js -a 0xaaaaaa -p 0xbbbbbb -d 0xcccccc