JavaScript Driver for BigchainDB

Inspired by js-bigchaindb-quickstart of @sohkhai [thanks]

Supports BigchainDB Server v0.10

Some naive helpers to get you on your way to making some transactions, if you'd like to use BigchainDB with JavaScript.

Aimed to support usage in browsers or node and ES∞+, so you'll probably need a babel here and a bundler there (or use one of the built versions), of which I expect you'll know quite well (otherwise, go check out js-reactor).

Contents

• Getting Started
• Usage
• Speed Optimizations
• Warnings
• API

Getting started

Install from npm

# install from npm
npm install js-bigchaindb-driver
# Install from GitHub - ssh
npm install git+ssh://github.com/bigchaindb/js-bigchaindb-driver.git
# Install from GitHub - https
npm install git+https://github.com/bigchaindb/js-bigchaindb-driver.git

Import / ES6

// ES6 Browser
import * as driver from 'js-bigchaindb-driver';
// ES<<6 Browser
let driver = require('js-bigchaindb-driver');
// ES<<6 CommonJS / node
let driver = require('js-bigchaindb-driver/dist/node');

Usage

import * as driver from 'js-bigchaindb-driver';

// http(s)://<bigchaindb-API-url>/ (e.g. http://localhost:9984/api/v1/)
const API_PATH = 'http://localhost:9984/api/v1/';

// create a new user with a public-private keypair
const alice = new driver.Ed25519Keypair();

// Create a transation
const tx = driver.Transaction.makeCreateTransaction(
    { assetMessage: 'My very own asset...' },
    { metaDataMessage: 'wrapped in a transaction' },
    [ driver.Transaction.makeOutput(
            driver.Transaction.makeEd25519Condition(alice.publicKey))
    ],
    alice.publicKey
);

// sign/fulfill the transaction
const txSigned = driver.Transaction.signTransaction(tx, alice.privateKey);

// send it off to BigchainDB
driver.Connection
    .postTransaction(txSigned, API_PATH)
    .then((res) => {
        // request the status of the transaction
        driver.Connection
            .getStatus(txSigned.id, API_PATH)
            .then((res) => console.log('Transaction status:', res.status))});

You may also be interested in some long-form tutorials with actual code.

The expected flow for making transactions:

1. Go get yourself some keypairs! (or a whole bunch of them, nobody's counting)
   • new driver.Ed25519Keypair()
2. Construct a transaction payload that you can send of to BigchainDB:
   • driver.Transaction.makeCreateTransaction() for creating a new asset or
   • driver.Transaction.makeTransferTransaction() for transfering an existing asset
3. A transaction needs an output (*):
   • driver.Transaction.makeOutput() still requires a crypto-condition
   • driver.Transaction.makeEd25519Condition() should do the trick for a simple public key output.
4. (Optional) You've got everything you need, except for an asset and metadata. Maybe define them (any JSON-serializable object will do).
5. Ok, now you've got a transaction, but we need you to sign it cause, you know... cryptography and ¯\_(ツ)_/¯:
   • driver.Transaction.signTransaction() allows you to sign with private keys.
6. Final step is to send the transaction off to BigchainDB:
   • driver.Connection.postTransaction()

(*) If you're not sure what any of this means (and you're as confused as I think you are right now), you might wanna go check out this and this and this first.

Speed Optimizations

This implementation plays "safe" by using JS-native (or downgradable) libraries for its crypto-related functions to keep compatibilities with the browser. If you do want some more speed, feel free to explore the following:

• chloride, or its underlying sodium library
• node-sha3 -- MAKE SURE to use steakknife's fork if the FIPS 202 upgrade hasn't been merged (otherwise, you'll run into all kinds of hashing problems)

Warnings

Crypto-conditions

Make sure you keep using a crypto-conditions implementation that implements the older v1 draft (e.g. five-bells-condition@v3.3.1). BigchainDB Server 0.10 does not implement the newer version of the spec and WILL fail if you to use a newer implementation of crypto-conditions.

SHA3

Make sure to use a SHA3 implementation that has been upgraded as per FIPS 202. Otherwise, the hashes you generate WILL be invalid in the eyes of the BigchainDB Server.

Ed25519

If you do end up replacing tweetnacl with chloride (or any other Ed25519 package), you might want to double check that it gives you a correct public/private (or verifying/signing, if they use that lingo) keypair.

An example BigchainDB Server-generated keypair (encoded in base58):

• Public: DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C
• Private: 7Gf5YRch2hYTyeLxqNLgTY63D9K5QH2UQ7LYFeBGuKvo

Your package should be able to take in the decoded version of the private key and return you the same public key (once you encode that to base58).