Getting Started

This guide walks through wiring a TUI into a Phoenix LiveView from scratch, then explains the two integration APIs and when to reach for each.

Project setup

phoenix_ex_ratatui runs alongside the rest of a normal Phoenix project — no special generator is needed. Add the deps:

# mix.exs
defp deps do
  [
    # …
    {:phoenix, "~> 1.7"},
    {:phoenix_live_view, "~> 1.1"},
    {:phoenix_ex_ratatui, "~> 0.1"}
  ]
end

Wire the JS hook. phoenix_ex_ratatui ships a top-level package.json, so it imports like any other npm module. Add it to the assets/package.json:

{
  "dependencies": {
    "phoenix": "file:../deps/phoenix",
    "phoenix_html": "file:../deps/phoenix_html",
    "phoenix_live_view": "file:../deps/phoenix_live_view",
    "phoenix_ex_ratatui": "file:../deps/phoenix_ex_ratatui"
  }
}

Then cd assets && npm install to symlink it, and import the hook in assets/js/app.js:

import { Socket } from "phoenix"
import { LiveSocket } from "phoenix_live_view"
import { PhoenixExRatatuiHook } from "phoenix_ex_ratatui"

const liveSocket = new LiveSocket("/live", Socket, {
  hooks: { PhoenixExRatatuiHook }
})

liveSocket.connect()

That's the only client-side wiring. The hook auto-discovers each TUI's container by phx-hook="PhoenixExRatatuiHook" and handles cell measurement, paint, keypress forwarding, and resize observation itself.

The unified-module pattern

Both APIs (PhoenixExRatatui.LiveView and PhoenixExRatatui.LiveComponent) are unified modules: the same module is both the Phoenix LiveView/LiveComponent AND the ExRatatui.App driving it.

The macro doesn't fight Phoenix's handle_info/2 callback (which takes a socket) and the App's handle_info/2 callback (which takes App state) — they have the same name and arity but different semantics. Instead, the macro auto-generates a hidden Module.Runtime proxy via @after_compile that conforms to ExRatatui.App by delegating to a small set of tui_* callbacks on the host module:

All are overridable; implement only what's needed. Phoenix's regular LV/LC callbacks (mount/3, render/1, handle_event/3, etc.) remain available and overridable through the same defoverridable mechanism.

Two ways to mount a TUI

Option A — Full-page TUI route (PhoenixExRatatui.LiveView)

When the page IS a TUI, write a unified module and mount it through the router's regular live/3 macro:

defmodule MyAppWeb.CounterLive do
  use PhoenixExRatatui.LiveView

  alias ExRatatui.Event.Key
  alias ExRatatui.Layout.Rect
  alias ExRatatui.Widgets.{Block, Paragraph}

  def tui_mount(_opts), do: {:ok, %{n: 0}}

  def tui_render(state, frame) do
    [
      {%Paragraph{
         text: "Count: #{state.n}\n\n+ increment   - decrement   q quit",
         block: %Block{title: " counter ", borders: [:all]}
       },
       %Rect{x: 0, y: 0, width: frame.width, height: frame.height}}
    ]
  end

  def tui_handle_event(%Key{code: "+"}, s), do: {:noreply, %{s | n: s.n + 1}}
  def tui_handle_event(%Key{code: "-"}, s), do: {:noreply, %{s | n: s.n - 1}}
  def tui_handle_event(%Key{code: "q"}, s), do: {:stop, s}
  def tui_handle_event(_, s), do: {:noreply, s}
end

In the router:

scope "/", MyAppWeb do
  pipe_through :browser
  live "/counter", CounterLive
end

That's the full integration. The @after_compile hook generates MyAppWeb.CounterLive.Runtime automatically — it's never referenced directly.

Threading socket data into the App

To pass per-connection context (current user, session, URL params) from the LiveView mount into tui_mount/1, override tui_mount_opts/1:

defmodule MyAppWeb.AdminTui do
  use PhoenixExRatatui.LiveView

  @impl Phoenix.LiveView
  def mount(_params, session, socket) do
    {:ok, socket} = super(nil, nil, socket)
    {:ok, assign(socket, :user_id, session["user_id"])}
  end

  def tui_mount_opts(socket), do: [user_id: socket.assigns.user_id]

  def tui_mount(opts), do: {:ok, %{user_id: opts[:user_id]}}
end

super/3 delegates to the macro's default mount/3 (which sets up internal assigns and trap_exit); layer additional assigns on top afterward. tui_mount_opts/1 reads them off the socket and returns the keyword list that becomes opts in tui_mount/1.

Option B — Embedded TUI (PhoenixExRatatui.LiveComponent)

When the page is a regular Phoenix dashboard with a TUI sidebar, dev console, or modal — anything where the TUI lives alongside other content the user already controls — write a unified LiveComponent:

defmodule MyAppWeb.SystemMonitorPanel do
  use PhoenixExRatatui.LiveComponent

  def tui_mount(_opts), do: {:ok, %{cpu: 0.0, mem: 0.0}}

  def tui_render(state, frame) do
    # widgets…
  end

  def tui_handle_event(_event, state), do: {:noreply, state}
end

Embed it inside any LiveView's render:

defmodule MyAppWeb.AdminLive do
  use MyAppWeb, :live_view

  def mount(_params, _session, socket) do
    {:ok, assign(socket, :recent_orders, fetch_recent_orders())}
  end

  def render(assigns) do
    ~H"""
    <h1>Admin Dashboard</h1>

    <div class="grid grid-cols-2 gap-4">
      <div>
        <h2>Recent Orders</h2>
        <ul>
          <li :for={order <- @recent_orders}>{order.id} — {order.total}</li>
        </ul>
      </div>

      <div>
        <h2>Live System Monitor</h2>
        <.live_component module={MyAppWeb.SystemMonitorPanel} id="admin-tui" />
      </div>
    </div>
    """
  end
end

The TUI's diff stream routes through Phoenix.LiveView.send_update/3 into the component's update/2 (LiveComponents have no handle_info — they share the parent LV's process). Everything else is identical to the full-page path.

Inter-page navigation

A TUI can request navigation to another LV route by returning a list of runtime intents from any handler. The intents flow through ExRatatui.Server's intent writer into the LV, which dispatches them to Phoenix.LiveView.push_navigate/2 (and its siblings):

defmodule MyAppWeb.LoginTui do
  use PhoenixExRatatui.LiveView

  alias ExRatatui.Event.Key

  def tui_mount(_opts), do: {:ok, %{}}

  def tui_render(_state, _frame), do: # …

  # Press <enter> → push_navigate to /dashboard
  def tui_handle_event(%Key{code: "enter"}, state) do
    {:noreply, state, intents: [{:navigate, "/dashboard"}]}
  end

  def tui_handle_event(_, state), do: {:noreply, state}
end

Recognised intent shapes:

Unrecognised intents are dropped (logged at warning level), so a TUI that returns an intent the host doesn't know how to handle stays alive instead of crashing.

Embedded LiveComponent navigation

Phoenix LV forbids redirects from inside LiveComponent.update/2, so when the embedded TUI emits a navigation intent the LiveComponent sends it to its parent LV process via send/2 and the parent dispatches. Add this clause to the parent LV:

def handle_info({:phoenix_ex_ratatui, :intent, intent}, socket) do
  {:noreply, PhoenixExRatatui.LiveView.dispatch_intent(socket, intent)}
end

If the parent is itself a PhoenixExRatatui.LiveView, the clause is generated automatically — nothing else is needed.

Stop-then-redirect

Intents from {:stop, state, intents: ...} transitions fire before the runtime server exits, so a TUI can return {:stop, state, intents: [{:redirect, "/login"}]} from a "logout" key and trust the redirect reaches the LV before the server's EXIT signal propagates.

Decision matrix

Telemetry

Both integrations emit the same :telemetry events, one layer above the events ex_ratatui already emits. Attach the default logger in dev with PhoenixExRatatui.Telemetry.attach_default_logger(level: :info), or wire Telemetry.Metrics for production dashboards. The Telemetry guide covers the full event tree, a Telemetry.Metrics example, and how the two event layers pair up.

What about ANSI / xterm.js / a real terminal in a browser?

That's kino_ex_ratatui — same parent library, but it's built around xterm.js and is the right pick for a real terminal emulator in the page.

phoenix_ex_ratatui is deliberately different: cells are pushed directly to the DOM as styled <span>s. The advantages are that the bundle is tiny (~5KB minified, no third-party deps), phones get real touch events, and the cell grid is just HTML — themeable with CSS, accessible to screen readers, copy/pasteable. The trade-off is no scrollback, no shell semantics, no ANSI alt-screen — if a TUI was relying on those, kino_ex_ratatui (or running the App over SSH) is the right call.