index.js

var express = require("express")
var request = require('request')
var morgan  = require('morgan')
var bodyParser = require('body-parser')
var compression = require('compression')

var app = express()
var TX_URI = new RegExp("^https://btc.blockr.io/api/v1/tx/raw/")

function allowCrossDomain(req, res, next) {
  res.header('Access-Control-Allow-Origin', process.env.CORS_ORIGINS)
  res.header('Access-Control-Allow-Methods', 'POST, GET')
  res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization, Content-Length, X-Requested-With')

  next()
}

app.use(morgan())
app.use(allowCrossDomain)
app.use(bodyParser.json())
app.use(bodyParser.urlencoded())
app.use(compression())

app.post('/', function(req, res){
  request({
    method: 'POST',
    uri: req.query.url,
    body: JSON.stringify({hex: req.body.hex}),
    header: { "Content-Type": "application/json" }
  }, function(err, response, body){
    res.statusCode = response.statusCode
    res.send(body);
  })
});

app.get('/', function(req, res){
  request({
    method: 'GET',
    uri: req.query.url
  }, function(err, response, body){
    res.statusCode = response.statusCode

    // express strips out body for 304
    if (res.statusCode === 200 && TX_URI.test(req.query.url)) {
      body = stripTransactionData(body)
    }
    res.send(body);
  })
});

function stripTransactionData(body) {
  var response = JSON.parse(body)
  var stripped = {
    status: response.status,
    data: []
  }

  stripped.data = response.data.map(function(d) {
    return {
      tx: {
        hex: d.tx.hex,
        blockhash: d.tx.blockhash,
        blockHeight: d.tx.blockHeight,
        blocktime: d.tx.blocktime,
        confirmations: d.tx.confirmations
      }
    }
  })

  return JSON.stringify(stripped)
}

app.listen(process.env.PORT || 9009);