Customizing error reports

In order to quickly reproduce and fix errors, it is often helpful to send additional application-specific diagnostic data to Bugsnag.

Adding callbacks

If you’d like to add diagnostic data to every error report, or adjust error reports conditionally, you can add callbacks which will be invoked each time a report will be sent:

Bugsnag.before_notify_callbacks << lambda {|report|
  # Add customer information to every report
  report.add_tab(:account, {
    paying_customer: current_user.organization.paying?

  # Add user information to every report
  report.user = {

# Your app code here

Callbacks are scoped to the current thread to avoid leaking request data between threads. For job queues (such as Sidekiq or Que), make sure the job’s callbacks are added to before_notify_callbacks during job initialisation.

See the report object for methods available inside the callback.

Custom error diagnostic data

If you are using custom error classes within your application, diagnostic data can be automatically attached to each error report within the exception class itself.

This is achieved by creating a bugsnag_meta_data function on the custom error class that returns a hash with the data you wish to attach.

class MyCustomError < StandardError
  attr_reader :metadata
  def initialize(message, metadata)
    @metadata = metadata

  def bugsnag_meta_data
     {tabname: metadata}

Bugsnag.notify("Error message", value1: '1', value2: {nested: 3}))

This will add a tab with the name tabname on the dashboard with the corresponding data listed in it.

The report object


Call add_tab on a report object to add a tab to the error report so that it would appear on your dashboard.

report.add_tab(:user_info, { name: })

The first parameter is the tab name that will appear in the error report and the second is the key, value list that will be displayed in the tab.


Set the project API key for the error report. The API key is normally set in the configuration, but it can be overridden to report to a different API key in some situations.

report.api_key = 'your-api-key-here'

Customize or filter breadcrumbs to be sent with the report. Modified breadcrumbs will not be validated again.

report.breadcrumbs.each { |breadcrumb| breadcrumb.meta_data = {} } # Clear the meta data


Set the context of the error report. This is notionally the location of the error and should be populated automatically. Context is displayed in the dashboard prominently.

report.context = 'billing'


Allows you to read the exceptions that will be combined into the report.

puts report.exceptions.first.message + ' found!'


Sets the grouping hash of the error report. All errors with the same grouping hash are grouped together. This is an advanced usage of the library and mis-using it will cause your errors not to group properly in your dashboard.

report.grouping_hash = exception.message + exception.class.to_s


Calling ignore! on a report object will cause the report to not be sent to Bugsnag. This means that you can choose dynamically not to send an error depending on application state or the error itself.

report.ignore! if foo == 'bar'


Provides access to the meta_data in the error report.

report.ignore! if report.meta_data[:sidekiq][:retry_count] < 2


Removes a tab completely from the error report



Set the severity of the error. Severity can be error, warning or info.

report.severity = 'error'


Creates a hashed summary of the report. Given keys are :error_class, :severity, and optionally :message.

summary = report.summary
puts "#{summary[:error_class]} occurred with message: #{summary[:message]}"


You can set or read the user with the user property of the report.

report.user = {

The breadcrumb object


A short description of the breadcrumbed event. This shows up prominently on the Bugsnag dashboard. += ': some extra context'

This has a maximum length of 30 characters, and will be trimmed to that limit if it’s too long.


Identifies what kind of event occurred.

breadcrumb.meta_data = {} if breadcrumb.type == Bugsnag::Breadcrumbs::PROCESS_BREADCRUMB_TYPE

There is a list of valid types within the Bugsnag::Breadcrumbs module, defaulting to MANUAL_BREADCRUMB_TYPE.


A hash of additional data about the event. This can help to determine if or how this event may have caused an error notification.

breadcrumb.meta_data[:authorized] = user_authorized?(user_id)

This data can only consist of String, Numeric, or TrueClass/FalseClass type objects, or nil, with non-conforming entries being removed.


Describes if the breadcrumb was automatically generated or not.

puts ? "Bugsnag generated" : "Manually created"

This cannot be modified.


The time the breadcrumb was created.

puts "Breadcrumb created at #{breadcrumb.timestamp}"

This cannot be modified.