Parse Ruby's Marshal strings into JavaScript objects/JSON
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Parse Ruby's Marshal strings into JavaScript objects/JSON.

This module could not have been built without this awesome blog post series.


npm install marshal


Basic use

var Marshal = require('marshal');
var m = new Marshal('0408220a68656c6c6f', 'hex');
console.log(m.parsed); // 'hello'

Decode a Rails cookie

This library was purpose-built for sharing a Rails cookie with an Express session.

See instore/rails-cookie-parser for an example.

Features / Limitations

Able to convert a Marshal string into a JavaScript object (not all types are supported, if you see one you would like supported please create an issue). i.e. Marshal.load()

Unable to convert a JavaScript object into a Marshal string. i.e. Marshal.dump()

Supported Types

  • nil (converted to null)
  • booleans
  • integers
  • floats (thank you @tgriesser!)
  • bignums (bignums are broken after v0.2.0, if you need bignum support please use v0.2.0)
  • raw strings
  • symbols
  • symbol links
  • object links
  • IVARs (encoded strings, regular expressions are not supported)
  • arrays
  • objects
  • hashes

Unsupported Types


From what I can tell, positive integers are unsigned and negative integers are signed. Thus, positive integers have twice the range as negative integers.


The bignum base conversion algorithm was adapted from MikeMcl/decimal.js which is copyright Michael Mclaughlin.