Tedchain is an open source distributed ledger technology. It is suited for organizations wishing to issue and manage digital assets in a robust, secure and scalable way. Visit tedchain.network for more information.

The full documentation for Tedchain is available at Github.

This module is a NodeJS client library to use in conjunction with the Tedchain server.

Getting started

Node.js

Install the module through NPM:

$ npm install tedchain

Import the module:

var tedchain = require("tedchain");

In the browser

Install the module through Bower:

$ bower install tedchain

Reference the scripts:

<script src="bower_components/bitcore-lib/bitcore-lib.min.js"></script>
<script src="bower_components/tedchain/dist/tedchain.min.js"></script>

Import the module:

var tedchain = require("tedchain");

Modules

The tedchain module exports the following objects:

• ApiClient: A class wrapping the Tedchain API calls.
• Schema: A set of classes (Schema.Record, Schema.Mutation and Schema.Transaction) that can be used for serialization and deserialization of transactions and mutations.
• TransactionBuilder: A class facilitating the construction, signature and submission of transactions to an Tedchain instance.
• LedgerPath: A class representing a path within the Tedchain structure.
• RecordKey: A class representing a record key.
• encoding: A submodule that contains methods that can be used for encoding and decoding integers and string to/from a ByteBuffer object.
• MutationSigner: A class that can be used to sign a mutation.
• ByteBuffer: A buffer of raw bytes.
• Long: A class for representing a 64 bit integer value.

Code samples

Query the balance of an account

This code queries an Tedchain server for the balance of the account represented by the path /p2pkh/Xat6UaXpQE9Dxv6rLtxY1peBkzC1SQDiEX/ for the asset represented by the path /asset/p2pkh/XcDCGPMtdrKxodQ4soFyYfDmr78gTvJ9jN/.

var tedchain = require("tedchain");
        
var client = new tedchain.ApiClient("http://localhost:8080/");

client.getAccountRecord(
    // Account path
    "/p2pkh/Xat6UaXpQE9Dxv6rLtxY1peBkzC1SQDiEX/",
    // Asset path
    "/asset/p2pkh/XcDCGPMtdrKxodQ4soFyYfDmr78gTvJ9jN/")
.then(function (result) {
    console.log("Balance: " + result.balance.toString());
});

Submit a transaction

This code submits a transaction that transfers 100 units of an asset from an issuance account (e.g. /asset/p2pkh/Xat6UaXpQE9Dxv6rLtxY1peBkzC1SQDiEX/) to a normal wallet account (e.g. /p2pkh/Xat6UaXpQE9Dxv6rLtxY1peBkzC1SQDiEX/).

var tedchain = require("tedchain");
var bitcore = require("bitcore-lib");

var seed = "0123456789abcdef0123456789abcdef";

// Load a private key from a seed
var privateKey = bitcore.HDPrivateKey.fromSeed(seed, "tedchain");
var address = privateKey.publicKey.toAddress();

// Calculate the accounts corresponding to the private key
var issuancePath = "/asset/p2pkh/" + address + "/";
var assetPath = issuancePath;
var walletPath = "/p2pkh/" + address + "/";

console.log("Issuance path: " + issuancePath);
console.log("Wallet path: " + walletPath);

// Create an Tedchain client and signer
var client = new tedchain.ApiClient("http://localhost:8080/");
var signer = new tedchain.MutationSigner(privateKey);

// Initialize the client
client.initialize()
.then(function () {
    // Create a new transaction builder
    return new tedchain.TransactionBuilder(client)
        // Add the key to the transaction builder
        .addSigningKey(signer)
        // Add some metadata to the transaction
        .setMetadata({ "memo": "Issued through NodeJS" })
        // Take 100 units of the asset from the issuance path
        .updateAccountRecord(issuancePath, assetPath, -100);
})
.then(function (transactionBuilder) {
    // Add 100 units of the asset to the target wallet path
    return transactionBuilder.updateAccountRecord(walletPath, assetPath, 100);
})
.then(function (transactionBuilder) {
    // Submit the transaction
    return transactionBuilder.submit();
})
.then(function (result) { console.log(result); });

Store data on the chain

This code submits a transaction recording a piece of arbitrary data (the storedData variable) into the chain. The data may be anything: arbitrary text, JSON data, XML data or even binary data.

var tedchain = require("tedchain");
var bitcore = require("bitcore-lib");

var seed = "0123456789abcdef0123456789abcdef";

// Load a private key from a seed
var privateKey = bitcore.HDPrivateKey.fromSeed(seed, "tedchain");
var address = privateKey.publicKey.toAddress();

// Calculate the accounts corresponding to the private key
var dataPath = "/asset/p2pkh/" + address + "/metadata/";
var recordName = "datarecord";
var storedData = "This is the data to store in the chain";

console.log("Account path: " + dataPath);
console.log("Record name: " + recordName);

// Create an Tedchain client and signer
var client = new tedchain.ApiClient("http://localhost:8080/");
var signer = new tedchain.MutationSigner(privateKey);

// Initialize the client
client.initialize()
.then(function () {
    // Retrieve the record being modified
    return client.getDataRecord(dataPath, recordName)
})
.then(function (dataRecord) {
    // Encode the data into a ByteBuffer
    var newValue = tedchain.encoding.encodeString(storedData);

    // Create a new transaction builder
    return new tedchain.TransactionBuilder(client)
        // Add the key to the transaction builder
        .addSigningKey(signer)
        // Modify the record
        .addRecord(dataRecord.key, newValue, dataRecord.version)
        // Submit the transaction
        .submit();
})
.then(function (result) { console.log(result); });

Other use

The Tedchain JavaScript client library is also used by the Tedchain web-wallet available on GitHub.

License

Copyright (c) 2014-2018 TEDLab Sciences Ltd