Node.js – smart contract integration with truffle-contract and infura.io

While running your own Ethereum node with geth by using web3js from node.js (backend) app is a common solution, connecting to a public Ethereum node such as infura.io and using [truffle-contract](https://github.com/trufflesuite/truffle-contract] gives some benefits: No need to maintain your own Ethereum node (syncing a full node requires huge storage space! (around 40 GB for Ropsten))…

Sending Bitcoin programmatically using BlockCypher API

BlockCypher provides convenient REST APIs to send cryptocurrency like Bitcoin easily. Here are two APIs that we can use to send Bitcoin from one address to another: 1. Build transaction skeleton https://api.blockcypher.com/v1/btc/test3/txs/new 2. Push signed transaction https://api.blockcypher.com/v1/btc/test3/txs/send Here are the step by steps of using those APIs in JavaScript (Node.js) in testnet3 Bitcoin network. First,…

Loopback automatic creation & modification timestamp

In certain cases, it’s convenience to have automatic creation & modification timestamp where system automatically records when and who create/update a record. So far, I find that the most efficient way to do this in Loopback is by utilizing hook feature. Based on the docs, there are 3 types of hooks provided by loopback based…