npm install objectstruct

var ostruct = require('objectstruct')
var example = ostruct({
  hello: 'string',
  list: [{           // [type] donates an array
    a: 'boolean',
    b: 'number',     // you can also set DoubleBE etc
    c: 'integer'     // uses a varint
  }],
  data: 'bytes'      // expect a Buffer object
  foo: {             // a nested object
    bar: 'boolean'
  }
})
var buf = example.encode({
  hello: 'world',
  list: [{
    a: true,
    b: 10.0,
    c: 10000
  }, {
    b: 1
  }],
  foo: {
    bar: true
  },
  data: new Buffer('test')
})
console.log(buf) // prints a buffer
var parsed = example.decode(buf)
console.log(parsed) // prints an object similar to above