Stats = require 'stats'
stats = new Stats
  namespace: 'applicationName'
  sdUrl: 'url to statsd'
  gaugePollPeriodMs: 5 * 1000 # has a default

# counters are sent to statsd
stats.increment 'counter', 1
stats.gauge 'gauge', 1
...

# gauges can take event emitters which set the gauge value
stats.gauge 'eventedGauge', event: 'foo', emitter: emitter
emitter.emit 'foo', 100

# gauges can take also a poll function which peridically
# updates the gauge value
stats.gauge 'time', => Date.now()

# key values that are not sent to stats
stats.key 'started-at', new Date.now()

# dynamically get the key value when needed
stats.key 'fun', ->
  #count something

...

# serve the json containing the counters and keys
# json from under '/status'
app.get '/status', stats.render