```ruby
require 'rubygems'

ENV['RACK_ENV'] ||= 'development'

require File.join(File.dirname(__FILE__), 'lib/metrics-api.rb')

use(Rack::Cors) do
  allow do
    origins '*'
    resource '*', :headers => :any, :methods => [:get]
  end
end

run MetricsApi
```

Make sure we're operating inside the bundle
user
```ruby
require 'rubygems'
require 'bundler'
Bundler.setup

ENV['RACK_ENV'] ||= 'development'

require File.join(File.dirname(__FILE__), 'lib/metrics-api.rb')

use(Rack::Cors) do
  allow do
    origins '*'
    resource '*', :headers => :any, :methods => [:get]
  end
end

run MetricsApi
```
assistant