mws-js

I find Node.js an absolute pleasure to work with and made this rough Marketplace web services client as one of my first projects. I still find it beats the snot out of PHP, Java, or C# packages Amazon publishes.
I use it for real-time integration and/or dashboards for e-commerce clients. Note: there may be tons of bugs since I updated the formatting to be a lot more user-friendly, but almost all of the documented functions and objects should work fine and dandy like cotton candy.

Usage

Super simple example

I will be creating some sample projects illustrating how to take advantage of complex/enum params and other more useful features of this library, but the most basic usage I could come up with goes something like:

var mws = require('mws'),
    client = new AmazonMwsClient('accessKeyId', 'secretAccessKey', 'merchantId', {});

// Get the service status of Sellers API endpoint and print it
client.invoke(new mws.sellers.requests.GetServiceStatus(), console.log);

var listOrders = new mws.orders.requests.ListOrders();
listOrders.set('MarketplaceId', 'marketplaceId')
          .set('CreatedAfter', new Date(2,14,2012));
client.invoke(listOrders, function(result) {
  console.log(result);
  // Do something fun with the results...
});