Installation in Sinatra

First, add MongoMapper to your Gemfile, and run bundle install:

gem 'mongo_mapper'
gem 'bson_ext'

If you’re not using Bundler.require in the top of your Sinatra application then you’ll need to require the MongoMapper library:

require 'mongo_mapper'

You’ll also need to set up your MongoDB connection in your configure method call. If you have a MongoDB URI for the database connection (i.e. on Heroku):

configure do
  MongoMapper.setup({'production' => {'uri' => ENV['MONGODB_URI']}}, 'production')
end

You can now define your models and start using MongoMapper in Sinatra!