Access MongoDB directly via JavaScript

MongoDB natively does not has a fully usable REST interface. You will need either Python based Sleepy Mongoose or Node.js based MongoDB Rest

Please see http://www.mongodb.org/display/DOCS/Http+Interface for more information.

Mongo's inbuilt REST interface is very basic & read only.

Connections to MongoDB occur over a socket; browsers communicate via http. That said, it's not difficult to write a back-end app that gives you pretty transparent access to MongoDB via JavaScript / REST / HTTP. That's essentially what's happening with Try Mongo, e.g. http://try.mongodb.org/ .

People have also started building some generic back-ends for this purpose. Here's one example: http://github.com/djsun/sinatra_resource

Not in the standard security context.

If you have a situation where you have elevated security rights (such as inside a custom browser extension) then it may become possible.

If you happen to host your database on MongoLabs, they also expose a REST API. Watch out, it's not secure, as an API key is passed with each request, but your could use it to retrieve public data through Javascript:

https://support.mongolab.com/entries/20433053-Is-there-a-REST-API-for-MongoDB-

Once you have your mongolab db setup, you can access it thru REST request such as

$.getJSON( "https://api.mongolab.com/api/1/databases/your-db/collections/your-collection/?      apiKey=your-key", function( json ) {
//console.log( "JSON Data: " + json );
}
);