5-Minute Guide

Overview

This guide will walk you through the basic functions of Chain Core:

Sample Code

All code samples in this guide can be viewed in a single, runnable script. Available languages:

Initialize the SDK

Create an instance of the SDK. By default, the SDK will try to access a core located at http://localhost:1999, which is the default if you’re running Chain Core locally.

Client client = new Client();
chain = Chain::Client.new
  • Java
  • Ruby

Create Keys

Create a new key in the Mock HSM.

MockHsm.Key key = MockHsm.Key.create(client);
key = chain.mock_hsm.keys.create
  • Java
  • Ruby

Initialize the HSM Signer

To be able to sign transactions, load the key into the HSM Signer, which will communicate with the Mock HSM.

HsmSigner.addKey(key, MockHsm.getSignerClient(client));
signer = Chain::HSMSigner.new
signer.add_key(key, chain.mock_hsm.signer_conn)
  • Java
  • Ruby

Create an Asset

Create a new asset, providing an alias, key, and quorum. The quorum is the threshold of keys that must sign a transaction issuing units of the asset.

new Asset.Builder()
  .setAlias("gold")
  .addRootXpub(key.xpub)
  .setQuorum(1)
  .create(client);
chain.assets.create(
  alias: :gold,
  root_xpubs: [key.xpub],
  quorum: 1
)
  • Java
  • Ruby

Create an Account

Create an account, providing an alias, key, and quorum. The quorum is the threshold of keys that must sign a transaction to spend asset units controlled by the account.

new Account.Builder()
  .setAlias("alice")
  .addRootXpub(key.xpub)
  .setQuorum(1)
  .create(client);
chain.accounts.create(
  alias: :alice,
  root_xpubs: [key.xpub],
  quorum: 1
)
  • Java
  • Ruby

Create a second account to interact with the first account.

new Account.Builder()
  .setAlias("bob")
  .addRootXpub(key.xpub)
  .setQuorum(1)
  .create(client);
chain.accounts.create(
  alias: :bob,
  root_xpubs: [key.xpub],
  quorum: 1
)
  • Java
  • Ruby

Issue Asset Units

Build, sign, and submit a transaction that issues new units of the gold asset into the alice account.

Transaction.Template issuance = new Transaction.Builder()
  .addAction(new Transaction.Action.Issue()
    .setAssetAlias("gold")
    .setAmount(100)
  ).addAction(new Transaction.Action.ControlWithAccount()
    .setAccountAlias("alice")
    .setAssetAlias("gold")
    .setAmount(100)
  ).build(client);

Transaction.submit(client, HsmSigner.sign(issuance));
issuance = chain.transactions.build do |b|
  b.issue asset_alias: :gold, amount: 100
  b.control_with_account account_alias: :alice, asset_alias: :gold, amount: 100
end

chain.transactions.submit(signer.sign(issuance))
  • Java
  • Ruby

Spend Asset Units

Build, sign, and submit a transaction that spends units of the gold asset from the alice account to the bob account.

Transaction.Template spending = new Transaction.Builder()
  .addAction(new Transaction.Action.SpendFromAccount()
    .setAccountAlias("alice")
    .setAssetAlias("gold")
    .setAmount(10))
  .addAction(new Transaction.Action.ControlWithAccount()
    .setAccountAlias("bob")
    .setAssetAlias("gold")
    .setAmount(10)
  ).build(client);

Transaction.submit(client, HsmSigner.sign(spending));
spending = chain.transactions.build do |b|
  b.spend_from_account account_alias: :alice, asset_alias: :gold, amount: 10
  b.control_with_account account_alias: :bob, asset_alias: :gold, amount: 10
end

chain.transactions.submit(signer.sign(spending))
  • Java
  • Ruby

Retire Asset Units

Build, sign, and submit a transaction that retires units of the gold asset from the bob account.

Transaction.Template retirement = new Transaction.Builder()
  .addAction(new Transaction.Action.SpendFromAccount()
    .setAccountAlias("bob")
    .setAssetAlias("gold")
    .setAmount(5)
  ).addAction(new Transaction.Action.Retire()
    .setAssetAlias("gold")
    .setAmount(5)
  ).build(client);

Transaction.submit(client, HsmSigner.sign(retirement));
retirement = chain.transactions.build do |b|
  b.spend_from_account account_alias: :bob, asset_alias: :gold, amount: 5
  b.retire asset_alias: :gold, amount: 5
end

chain.transactions.submit(signer.sign(retirement))
  • Java
  • Ruby