Exploring Hedera

Welcome to this Hedera High Level Wrapper package.

I've encapsulated a couple of functions within this repository.

This tutorial is split in two sections.

Section one incorporates some theoretical knowledge.

Section two incorporates a technical and programmatical approach to the Hedera network

Install & Prepare

Install dependencies to ensure examples are executable

yarn

Create yourself an account

yarn create-account

or create it here and get your testnet funds:

Hedera Account

Section one: Things to know

What is Hedera?

Hedera's Consensus

The Hedera public network is proof-of-stake and built on the open source hashgraph distributed consensus algorithm, invented by Dr. Leemon Baird, Hedera Co-founder and Chief Scientist. The hashgraph consensus algorithm provides near-perfect efficiency in bandwidth usage and consequently can process hundreds of thousands of transactions per second in a single shard (a fully connected, peer-to-peer mesh of nodes in a network).

Unlike a traditional proof-of-work blockchain, which selects a single miner to choose the next block, the community of nodes running hashgraph come to an agreement on which transactions to add to the ledger as a collective. Through gossip-about-gossip and virtual voting, the hashgraph network comes to consensus on both the validity and the consensus timestamp of every transaction. If the transaction is valid and within the appropriate time, the ledger’s state will be updated to include the transaction with 100% certainty (finality).

In blockchain, consensus rules require that blocks eventually settle in a single, longest chain, agreed upon by the community. If two blocks are created at the same time, the network nodes will eventually choose one chain to continue and discard the other one, lest the blockchain “fork” into two different chains. It is like a growing tree that is constantly having all but one of its branches chopped off.

Hederas Application Use Cases

Hedera offers 3 major application uses cases.

1. Consensus Service
2. Token Service
3. Smart Contract Service

All of them can be coded with Typescript

1. Consensus Service

The Hedera Consensus Service offers applications direct access to the native speed, security, and fair ordering guarantees of the hashgraph consensus algorithm. Using this service, clients can submit messages to the Hedera public ledger for time-stamping and ordering. Clients can also encrypt the message contents, ensuring an application's ability to preserve their user's privacy and prevent the publishing of PII.

Messages can include important actionable information in them, events such as for a money transfer settlement, user engagements in an advertising platform, tracking of provenance in a supply chain, and more. These ordered messages will flow out to mirror nodes or clients of mirror nodes for processing in the consensus order. By using Hedera for tamper-proof and verifiable logging of transactions, disparate participants and systems have a real-time view into application events.

Create a topic

    // Create a new topic
const transactionId = new ConsensusTopicCreateTransaction().execute(client);

// Grab the newly generated topic ID
const topicId = transactionId.getReceipt(client).getConsensusTopicId();

Create your first message

    // Submit a message to a topic
const response = new ConsensusMessageSubmitTransaction()
    .setTopicId(topicId)
    .setMessage("Hellooooooo")
    .execute(client)
    .getReceipt(client);

2. Token Service

The native Hedera Token Service offers applications the ability to perform configuration, minting, and management of fungible and non-fungible tokens on Hedera. Tokens on Hedera achieve 10,000 transactions per second, settle with finality immediately, and always cost $0.0001 USD, paid in HBAR, to transfer.

Developers have fine-grained control over tokens and accounts on Hedera, with key and token configurations that deliver flexibility for account KYC verification and freeze, token supply management, transfer, and more. For full layer 1 programmability, you can integrate any type of token minted using Hedera Token Service directly into your Solidity smart contract.

Examples are shown in section 2

3. Smart Contracts on Hedera

The Hedera Smart Contract service lets you program in Solidity and utilizes the Besu Ethereum Virtual Machine (EVM). The Besu EVM has been specifically optimized for the Hedera network and hashgraph consensus, allowing for hundreds of transactions per second, low and predictable fees, a carbon-negative footprint, and incredible performance at 15 million gas per second.

You can write the contract in Solidity, deploy it and access it through the Hedera SDK with Typescript (e.g.)

Examples are shown in section 2

Section Two: Let's get practical

Each example is presented with a specific testcase. Hence, you can run the example yourself and play around.

⚠ Watch out for ACT comments

Each test contains an ACT comment.

This is the part where I abstracted things away to get a more readable test case.

Hence, by analyzing the method marked with ACT you can see the necessary steps you need to undergo to implement this on your end.

---

Create a client

Create your Hedera Testnet Client to interact with Hedera

const clientConfiguration: ClientConfiguration = {
    accountId: TEST_ACCOUNT_ID,
    accountPrivateKey: TEST_MY_PRIVATE_KEY,
    network: "testnet",
    options: {
        defaultMaxTransactionFee: 50,
        defaultMaxQueryPayment: 50,
    },
};

/** @ACT: Get new client */
const client = createClient(clientConfiguration);

---

Create an account

Create an Hedera Testnet Account

const client = createClient({
    accountId: TEST_ACCOUNT_ID,
    accountPrivateKey: TEST_MY_PRIVATE_KEY,
    network: "testnet",
});

/** @ACT: Create new Account */
const {
    accountId,
    accountCreationReceipt
} = await createAccount({client});

---

Create an transfer

Transfer HBar from A to B

const client = createClient({
    accountId: TEST_ACCOUNT_ID,
    accountPrivateKey: TEST_MY_PRIVATE_KEY,
    network: "testnet",
});

/** @ACT: Create new account */
const {accountId: receiverAccountId} = await createAccount({client});

/** @ACT: Transfer HBar */
const txResult = await transfer(
    client,
    AccountId.fromString(TEST_ACCOUNT_ID),
    receiverAccountId,
    1,
);

---

Create a token

Create yourself a token, either fungle or non-fungible.

    const tokenConfig: TokenConfig = {
        account: {
            id: TEST_ACCOUNT_ID,
            privateKey: TEST_MY_PRIVATE_KEY
        },
        initialTokenSupply: 1_000_000,
        tokenDecimals: "10",
        tokenName: "Fungible Token",
        tokenSymbol: "FUNGI",
        type: TokenType.FungibleCommon
}

/** @ACT: Create new token */
const token = await createToken(tokenConfig);