Introduction
Terminal user interfaces have long been associated with simple command‑line tools, but recent advances in text‑based UI frameworks have turned the console into a playground for rich, interactive applications. One of the most exciting developments in this space is the Textual framework, a Python library that brings the declarative, component‑driven philosophy of modern web frameworks to the terminal. By leveraging Textual, developers can build dashboards that feel as responsive and dynamic as their browser‑based counterparts, all while running inside a lightweight terminal session.
In this tutorial we will walk through the process of building a fully interactive, reactive, and dynamic data dashboard using Textual. We will start from a blank project and progressively add widgets, layout logic, reactive state management, and event handling. Each step will be accompanied by code snippets that you can copy, paste, and run immediately, so you can see how the interface evolves in real time. By the end of the article you will understand how Textual’s reactive system works, how to compose complex layouts with panels and grids, and how to tie user input to live data updates.
The goal of this guide is not only to demonstrate the mechanics of Textual but also to illustrate how terminal‑first UI frameworks can match the expressiveness of modern web dashboards. Whether you are a data scientist who wants to monitor metrics on a remote server, a DevOps engineer who needs a quick overview of system health, or a hobbyist exploring new ways to present information, this tutorial will give you the tools to create a polished, production‑ready dashboard that runs in any terminal.
Main Content
Building the Dashboard
The first thing we need to do is set up a minimal Textual application. Textual follows a component‑based architecture similar to React or Vue, where the UI is described as a tree of widgets. The root of this tree is the App class, which you extend to define your own application logic. Inside the on_mount method you can create and add child widgets. For our dashboard we start with a simple header, a body area for charts and tables, and a footer that displays status information.
from textual.app import App
from textual.widgets import Header, Footer, Static
class DashboardApp(App):
async def on_mount(self) -> None:
await self.view.dock(Header(), edge="top")
await self.view.dock(Footer(), edge="bottom")
await self.view.dock(Static("Loading…"), edge="left", size=30)
await self.view.dock(Static("Loading…"), edge="right", size=30)
await self.view.dock(Static("Loading…"), edge="top", size=3)
await self.view.dock(Static("Loading…"), edge="bottom", size=3)
This skeleton creates a four‑pane layout that will later host our charts and tables. The Static widgets act as placeholders until we replace them with more sophisticated components.
Crafting Reactive State
A key feature of Textual is its reactive state system. Reactive variables are defined with the reactive decorator, and any change to them automatically triggers a re‑render of dependent widgets. This is analogous to state hooks in React, but it is built into the framework’s core.
For a data dashboard we typically need to keep track of metrics, filter selections, and user preferences. We can declare these as reactive attributes on the App class:
from textual.reactive import reactive
class DashboardApp(App):
metrics = reactive({})
filter = reactive("all")
Whenever metrics or filter changes, Textual will call the watch_* methods that we can define to update the UI. For example, a watch_metrics method could refresh a chart widget to display the latest values.
Wiring Event Flows
Interaction in Textual is driven by events. When a user presses a key, clicks a button, or scrolls a list, an event object is generated and propagated through the widget tree. By overriding event handlers such as on_key or on_click, we can capture these actions and modify reactive state accordingly.
In our dashboard we might want to allow the user to switch between different data views by pressing the number keys. We can implement this by listening for key events and updating the filter reactive variable:
async def on_key(self, event) -> None:
if event.key in {"1", "2", "3"}:
self.filter = event.key
Because filter is reactive, the watch_filter method will automatically re‑render any widgets that depend on it, ensuring the UI stays in sync with the user’s choices.
Styling and Layout
Textual gives developers fine‑grained control over layout using a combination of Dock, Grid, and Container widgets. For a dashboard, a grid layout is often the most natural choice, as it allows you to place charts, tables, and status panels in a structured, responsive manner.
from textual.widgets import Grid
class DashboardApp(App):
async def on_mount(self) -> None:
grid = Grid()
grid.add_column("left", size=30)
grid.add_column("center", fraction=1)
grid.add_column("right", size=30)
grid.add_row("top", size=3)
grid.add_row("middle", fraction=1)
grid.add_row("bottom", size=3)
grid.add_areas(
header="left-start|center-end|right-end",
body="left-start|center-end|right-end",
footer="left-start|center-end|right-end",
)
await self.view.dock(grid, edge="top")
Once the grid is in place, you can drop widgets into each area. Textual’s styling system uses CSS‑like syntax, allowing you to define colors, borders, and padding in a separate stylesheet or inline. This separation of concerns keeps the Python code focused on logic while the stylesheet handles presentation.
Testing and Iteration
Because Textual runs in the terminal, testing can be done locally on any machine with a modern terminal emulator. However, to ensure that the dashboard behaves correctly across different terminal sizes, it is useful to write automated tests that simulate resizing events and verify that widgets maintain their layout. Textual’s testing utilities provide a TestApp class that can be used to programmatically interact with the UI and assert on its state.
from textual.testing import TestApp
async def test_dashboard_layout():
app = TestApp(DashboardApp)
await app.start()
await app.resize(120, 40)
assert app.query_one("Header").size.width == 120
await app.stop()
Iterating quickly is one of Textual’s biggest strengths. By running the application in watch mode, you can edit code and see changes reflected instantly, making the development cycle fast and enjoyable.
Conclusion
Building a terminal‑based dashboard that feels as interactive and dynamic as a web application is no longer a niche pursuit. With Textual, developers gain access to a modern, component‑driven framework that brings reactive state, declarative layouts, and rich event handling to the console. By following the steps outlined in this tutorial—setting up the application skeleton, defining reactive variables, wiring event flows, and styling the layout—you can create dashboards that run anywhere a terminal is available, from local development machines to remote servers accessed via SSH.
The power of Textual lies in its ability to abstract away low‑level terminal control while still exposing the full flexibility needed for complex UIs. Whether you are visualizing real‑time metrics, monitoring logs, or presenting data tables, the patterns demonstrated here provide a solid foundation for building professional‑grade terminal dashboards.
Call to Action
If you’re ready to bring your data dashboards into the terminal, start by cloning the example repository that accompanies this tutorial. Experiment with adding new widgets, tweaking the reactive logic, and customizing the CSS to match your brand. Share your creations on GitHub or a personal blog to inspire others in the community. And if you run into challenges, join the growing Textual community on Discord or the official forums—there’s a wealth of knowledge waiting to help you turn your terminal into a powerful, interactive data hub.