RequestMeter is a Rack middleware gem for Rails applications that limits API requests per API key within a specified timeframe.

It is ideal for Rails APIs wanting built-in request limits.

For the full documentation check RubyDocs

Install the gem and add to the application's Gemfile by executing:

bundle add request_meter

If bundler is not being used to manage dependencies, install the gem by executing:

gem install request_meter

Add this line to config/application.rb

Rails.application.config.middleware.use RequestMeter::Middleware

Example RequestMeter configuration in config/initializers/request_meter.rb:

RequestMeter.configure do |config|
  config.api_key_header = "X-API-Key"
  config.cache_client = Rails.application.config.redis
  config.quota_limit = -> (api_key) {
    user = User.find_by(api_key: api_key)
    user&.quota_limit
  }
  config.quota_period_seconds = -> (api_key) {
    user = User.find_by(api_key: api_key)
    user&.quota_period_seconds
  }
end

• api_key_header used to get the API key from the request headers

  • default: X-API-Key

• quota_limit maximum number of requests that can be performed in the timeframe quota_period_seconds by an API key.

  • default: 1000
  • type: Proc or Integer

• quota_period_seconds number of seconds in a timeframe

  • default: 3600
  • type: Proc or Integer

• cache_client Client used to track request counts. Note: Only has support for Redis

The default configuration defines a global limit of 1000 requests per hour

For custom behavior (e.g., per-user limits), use a Proc to dynamically determine values.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

Bug reports, pull requests and ideas for improvement are welcome on GitHub at https://github.com/mihai9909/request_meter.

The gem is available as open source under the terms of the MIT License.