bootstrap.js

module.exports.bootstrap = function (cb) {

  // Ensure we have 2dsphere index on Property so GeoSpatial queries can work!
  sails.models.YOURMODEL.native(function (err, collection) {
    collection.ensureIndex({ coordinates: '2dsphere' }, function () {

      // It's very important to trigger this callack method when you are finished 
      // with the bootstrap!  (otherwise your server will never lift, since it's waiting on the bootstrap)
      cb();

    });
  });


};

model.js

module.exports = {
  
  attributes: {
    
    coordinates: {
      type: 'json'
    }
      
  },
  
  /*
  * Search models based on location
  */
  search: function (conditions) {

    // Let's build up a MongoDB query
    var query = {};

    // We need to use `native` for geo queries
    Property.native(function (err, collection) {

      // Co-ordinates are passed from the client side (GMaps JS API)
      // Note that we don't get them server-side because apparently 
      // the server-side API isn't designed for real-time user searches. 
      // Probably too slow or something.
      query.coordinates = {
        $near: {
          $geometry: {
            type: "Point",  
            coordinates: [ // long then lat
              conditions.coordinates.lng, 
              conditions.coordinates.lat 
            ]
          },
          // $maxDistance : <distance in meters> // TODO
        }
      };

    });


  }
  
}