Radar is a tool which provides a drop-in solution to catching and reporting errors in your Ruby applications in customizable ways.

Radar is not a typical exception notifier such as Hoptoad and Exceptional since the former are built with Rails apps in mind, logging to a central server. Instead, Radar was initially built for Vagrant, a command line tool. And instead of solely logging to a central server, Radar supports logging in configurable ways (to a file, to a server, to a growl notification, etc.)

Radar was built out of the need for an easy automated solution to catching exceptions and gathering information, since I noticed that every time a stack trace was outputted for Vagrant, I was asking the user all the same questions which could've easily have been gathered automatically. Now, Vagrant users can simply send me the radar output and I don't have to ask for any more information 90% of the time.

Brief Feature Breakdown

  • Reporters allow Radar to report anywhere: a file, a server, email, etc.
  • Data extensions to add additional contextual data to exceptions
  • Matchers to filter exceptions which Radar reports
  • Run multiple Radar "applications" side-by-side to catch and report different exceptions to different places
  • Integration with 3rd party software: Rack, Rails 3.

Quick Start

gem install radar

Then just begin logging exceptions in your application:

r = Radar::Application.new(:my_application)
r.reporters.use :file

You can also tell Radar to attach itself to Ruby's at_exit hook so it can catch application-crashing exceptions automatically:


Both of the above methods can be used together, of course.

Since the above enabled the FileReporter for the application, reported exceptions will be stored in a text file on the local filesystem, by default at ~/.radar/errors/my_application. Sample contents of the exception data generated by default is shown below. Note that you can add your own custom data to this output by using data extensions (covered in the user guide).

      "message":"This was an example exception",
         "test.rb:28:in `<main>'"

Also, instead of assigning the application to a variable, you may also look it up later anywhere in your application:


# Or the shorthand:

Documentation and User Guide

For more details on configuring Radar, please view the user guide, which is a detailed overview of Radar and all of its features.

Reporting Bugs and Requesting Features

Please use the issues section to report bugs and request features. This section is also used as the TODO area for the Radar gem.


To hack on Radar, you'll need bundler which can be installed with a simple gem install bundler. Then, do the following:

bundle install

This will run the test suite, which should come back all green! Then you're good to go.

The general steps to contributing a new change are:

  1. Fork the repository
  2. Make your changes, writing tests if necessary
  3. Open an issue with the feature and a link to your fork or a gist with a patch.
  4. Wait patiently, for I am but one man.