Adding Context to Errors

Honeybadger can display additional custom key/value metadata — or "context" — with each error report. Context is what you're looking for if:

You want to record the current user's id or email address at the time of an exception
You need to send raw POST data for use in debugging
You have any other metadata you'd like to send with an exception

There are two ways to add context to errors in your code: global and local. While you can add any key/value data to context, a few keys have a special meaning in Honeybadger.

Global Context

Honeybadger.context/1 is provided for adding extra data to the notification that gets sent to Honeybadger. You can make use of this in places such as a Plug in your Phoenix Router or Controller to ensure useful debugging data is sent along.

elixir

  

def MyPhoenixApp.Controller
  use MyPhoenixApp.Web, :controller

  plug :set_honeybadger_context

  def set_honeybadger_context(conn, _opts) do
    user = get_user(conn)
    Honeybadger.context(user_id: user.id, account: user.account.name)
    conn
  end
end

Honeybadger.context/1 stores the context data in the process dictionary, so it will be sent with errors/notifications on the same process. The following Honeybadger.notify/1 call will not see the context data set in the previous line.

elixir

  

Honeybadger.context(user_id: 5)
Task.start(fn ->
  # this notify does not see the context set earlier
  # as this runs in a different elixir/erlang process.
  Honeybadger.notify(%RuntimeError{message: "critical error"})
end)

Local Context

You can also add context to a manual error report using the metadata option, like this:

elixir

context = %{user_id: 5, account_name: "Foo"}
Honeybadger.notify(exception, metadata: context, stacktrace: __STACKTRACE__)

Local context always overrides any global values when the error is reported.

Special Context Keys

While you can add any key/value data to context, a few keys have special meaning in Honeybadger:

Option	Description
`user_id`	The `String` user ID used by Honeybadger to aggregate user data across occurrences on the error page.
`user_email`	Same as `user_id`, but for email addresses

Limits

Honeybadger uses the following limits to ensure the service operates smoothly for everyone:

Nested objects have a max depth of 20
Context values have a max size of 64Kb

When an error notification includes context data that exceed these limits, the context data will be truncated, and the notification will still be processed.