# To get started with Solidity + Truffle

See our tutorial on Truffle and Solidity

# To get started with Golang Contracts

See our Golang Contracts

# To get started with universal transaction signing

Basechain has the ability to verify and accept transactions signed by native Ethereum wallets. In a nutshell, users can simply use their MetaMask account or any other native Ethereum wallet — further blending the line between Layer 1 and Layer 2.

In the next sections, we'll briefly walk you through the setup required to enable universal transaction signing in your app.

# Connecting to Loom

The first thing we want to do is to instantiate a new Client:

this.client = new Client(
  this.chainId,
  this.writeUrl,
  this.readUrl
)

Once the client gets instantiated, we must force personal sign by pretending to be MetaMask no matter what the web3 provider actually is:

let provider = this.web3js.currentProvider
provider.isMetaMask = true
const ethersProvider = new ethers.providers.Web3Provider(provider)

Next, let's call the createDefaultTxMiddleware function as follows:

this.client.txMiddleware = createDefaultTxMiddleware(this.client, privateKey)

This allows us to create the default set of tx middleware required to successfully commit transactions to Loom.

# Configuring LoomProvider

Now, we want to instantiate and configure LoomProvider:

this.loomProvider = new LoomProvider(this.client, privateKey)
this.loomProvider.callerChainId = this.callerChainId
this.loomProvider.setMiddlewaresForAddress(to.local.toString(), [
  new NonceTxMiddleware(
    new Address(this.callerChainId, LocalAddress.fromHexString(this.ethAddress)),
    this.client
  ),
  new SignedEthTxMiddleware(signer)
])

Note that we're using the SignedEthTxMiddleware which lets us sign transactions via an Ethereum compatible wallet like Metamask.

# Instantianting the contract

For the scope of this example, we are using the SimpleStore smart contract. Instantiating it is as simple as:

const web3 = new Web3(this.loomProvider)
this.contract = new web3.eth.Contract(SimpleStoreJSON.abi, SimpleStoreJSON.networks[this.networkId].address)

# Universal transaction signing in action

Now, to execute the set method of our smart contract, we can do something like this:

await this.contract.methods
  .set(value)
  .send({
    from: this.ethAddress
  })

If everything works well you should see a Metamask popup asking you to confirm the transaction:

Note that you just signed transactions on Loom without even accessing your eth wallet keys😉.

# Demo Project

We've built a small demo project to showcase this functionality. The source code is available here.

# Other Wallets

If you use Portis or Fortmatic, head over to this page.