# `Letterbox.Dev.Router`
[🔗](https://github.com/hattoriai/letterbox/blob/v0.1.0-rc.0/lib/letterbox/dev/router.ex#L1)

The development page: write an email to the app and see what became of
it, as Action Mailbox's conductor does. Mounted in the app's router,
where only developers reach it:

    import Letterbox.Dev.Router

    if Application.compile_env(:my_app, :dev_routes) do
      scope "/dev" do
        pipe_through :browser
        letterbox_dev "/letterbox"
      end
    end

At `/dev/letterbox`:

  * the messages, the newest first, with their status, refreshed while
    they change;
  * a form to write an email, with attachments, that is delivered as an
    ingress's would be (`ingress: "dev"`), routed and given to its
    mailbox;
  * each message as its mailbox got it (`Letterbox.Message`): its status
    and error, Retry and Delete, its text, its HTML in a frame that runs
    no script and loads nothing from elsewhere, its attachments and its
    raw email.

It is a page of its own, with its own style sheet and script, served
under the mount: nothing to add to the app's assets. It is a library
mounted with [PhoenixMountable](https://hexdocs.pm/phoenix_mountable), so
it takes PhoenixMountable's options (`:as`, `:on_mount`, …).

# `letterbox_dev`
*macro* 

Mounts Letterbox.Dev.Router at `path` in a host router.

    import Letterbox.Dev.Router

    scope "/" do
      pipe_through :browser
      letterbox_dev "/letterbox"
    end

Every mount also takes the options listed in `PhoenixMountable`, such as
`:as`, `:on_mount` and `:csp_nonce_assign_key`.

---

*Consult [api-reference.md](api-reference.md) for complete listing*