Rack::TestApp is another testing helper library for Rack application. IMO it is more intuitive than Rack::Test.

A Rack endpoint that generates cache manifests and other useful HTML5 offline utilities that are useful on the server-side. Rack::Offline also provides a conventional Rails endpoint (Rails::Offline) that configures Rack::Offline using expected Rails settings

Because you don't allow strangers into your app, and OAuth 2.0 is the new awesome.

If you are creating Rack middleware that changes the HTML response, use Rack::Mason to get a head start. Rack::Mason takes care of the boilerplate Rack glue so that you can focus on simply changing the HTML. Notethis is a fork from https://github.com/techiferous/rack-mason (c) techiferous@gmail.com

This Rack middleware records incoming Rack request and responses in a VCR compatible format.

Flexible rate limits for your Rack apps

A client wrapper around a Rack app or HTTP

Tools for monitoring Rack apps in production.

This is Rack middleware that makes your app compliant with the 'EU ePrivacy Directive'

Rack::Debug is a middleware that provides a simple interface to ruby-debug. Helps debug apps running in Passenger.

Rack middleware for Weixin apps: message validation/parser/generator

Rack OpenTracing middleware

JSON Schema based Rack middlewares

Rack::Debug adds a middlerware interface to ruby-debug http://github.com/github/rack-debug

Rack::Brotli enables Google's Brotli compression on HTTP responses

Rack::GridServe is a Rack middleware for serving files stored in MongoDB GridFS. It is meant as a simple replacement for Rack::GridFS until it is ready for Mongo driver version 2.0 and above.

Rack::State is middleware that securely stores and manages object state. Applications use the Manager API to set, get, and delete state of any object that requires persistence in a stateless environment. Rack::State is similar to Rack::Session, but provides state management for multiple objects...

Rack::EnvInspector is a Rack middleware for debugging that allows you to dump the Rack environment by appending a query parameter to the URL.

Rack::Synctime is a simple Rack middleware that returns sync time (time when request started) in HTTP headers (#{Rack::Synctime::DEFAULT_HEADER_NAME} by default). Header name can be changed also sync time can be modified using time offset i.e. -5 seconds (server time in seconds decreased by 5) et...

Rack::RequestID is a Rack middleware for generating request IDs. It generates a request GUID for every request (if one was not already provided) and inserts the request ID as a response header.