Reimagine what your Tidbyt can do

Pixbyt is a self-hosted Tidbyt app server for advanced apps
that aren't supported by the official community app server
that you can access through Tidbyt's mobile app.

---

crossword	jeopardy	common-misconceptions	owen-wilson-facts
plex	apple-tv	letterboxd	parcelapp
homebridge-unifi	guess-the-flag	ffmpeg	revolution
hello-world	dadjoke	speedtest	Your next Tidbyt app

---

Your Tidbyt does not run apps directly; it depends on a server to periodically run apps and push the resulting images to the device. When you install a community app through Tidbyt's mobile app, the app runs on Tidbyt's official app server. For security reasons, there are a ton of limitations on what these apps are allowed to do, which means some awesome app ideas are impossible to implement.

Apps running on Pixbyt have none of these limitations:

• Run Python scripts and packages, not just Starlark applets
• Reach local network resources, not just the public internet
• Work with complex APIs, not just simple REST HTTP requests
• Read local files, like images or JSON
• Organize your source code across multiple modules

Pixbyt lets you realize your wildest Tidbyt dreams by making it easy to:

• build advanced Tidbyt apps,
• install advanced apps built by the community,
• manage multiple Tidbyts and apps,
• package apps together in a Docker image, and
• launch the app server using Docker Compose.

How it works

Pixbyt's advanced features are enabled by tap-pixlet, an unofficial Tidbyt app runner that extends Pixlet (the official Tidbyt app development framework) with an unofficial standard library named Pixlib, similar to how Starlib is the unofficial standard library for Starlark (the Python-like language Tidbyt apps are written in). Pixlib comes with functions like file.read, file.exec, font.height, html.unescape, and html.xpath, helpful constants like const.WIDTH, const.HEIGHT, and const.FPS, and overloads load to support local modules.

Pixbyt uses tap-pixlet to run apps, target-tidbyt and target-webp to push the resulting images to your Tidbyt or WebP image files, Airflow to run apps on a schedule, and Meltano to tie these components together. Pixbyt also includes resources to package your apps into a Docker image (locally or automatically on GitHub Actions) and launch it using Docker Compose.

Try it out

This repo defines a Pixbyt app server with a single hello-world app that shows off some of its advanced features. It automatically builds a ghcr.io/douwem/pixbyt:main Docker image that can be launched using Docker Compose to render the app to a Tidbyt device every hour:

To quickly see Pixbyt in action, you can open this repo in GitHub Codespaces and render the hello-world app to a WebP image or your own Tidbyt before you add your own apps. Codespaces will automatically install the necessary dependencies and launch you into a web-based VS Code editor.

1. Click the green "Use this template" button at the top of this page

2. Choose "Open in a codespace" and wait for the codespace to start

3. Optionally, update the HELLO_WORLD_NAME environment variable in .env to replace world with your own name.

4. Render app to a WebP image file:

   TAP_PIXLET_MAGNIFICATION=8 meltano run hello-world--webp

   The image will be created at output/hello-world/<timestamp>.webp. The exact path is also printed in the command output.

5. Render app to your Tidbyt:

   1. Find your Device ID and Key in the Tidbyt mobile app under Settings > General > Get API Key.

   2. Update the TIDBYT_DEVICE_ID and TIDBYT_KEY environment variables in .env.

   3. Render the hello-world app and send it to your Tidbyt (in the foreground):

      TAP_PIXLET_BACKGROUND=false meltano run hello-world

Set up your own

When you're ready to start using apps other than hello-world, follow the steps below to build your own Pixbyt app server using this repo as a template:

1. Create your own Pixbyt repo

Option A: GitHub Codespaces

If you've already opened this template repo in a codespace using the steps above:

1. Click the "Source Control" icon in the sidebar
2. Click "Publish"

If you haven't launched a codespace yet:

1. Click the green "Use this template" button at the top of this page
2. Choose "Open in a codespace"

Option B: Build locally

1. Click the green "Use this template" button at the top of this page

2. Choose "Create a new repository"

3. Create a new (private) repo

4. Clone your new repository and enter the new directory:

   git clone [email protected]:<username>/pixbyt.git
   cd pixbyt

2. Configure Pixbyt

1. If the .env configuration file doesn't exist yet, create it from the sample:

   cp .env.sample .env

2. Update the TZ environment variable in .env to your "TZ" timezone identifier. This is used by many apps that show the (relative) date and time.

Option A: Configure just one Tidbyt

1. Find your Device ID and Key in the Tidbyt mobile app under Settings > General > Get API Key.
2. Update the TIDBYT_DEVICE_ID and TIDBYT_KEY environment variables in .env.

Option B: Configure multiple Tidbyts

1. If devices.yml doesn't exists yet, create it from the sample:

   cp devices.yml.sample devices.yml

2. For each device:

   1. Add the device to devices.yml under devices::

      devices:
      # ...
      - name: <name>
        id: $TIDBYT_<NAME>_DEVICE_ID
        key: $TIDBYT_<NAME>_KEY

      1. Replace <name> with the room name or another identifier.
      2. Replace <NAME> with the uppercased version thereof.

      For example:

      devices:
      # ...
      - name: office
        id: $TIDBYT_OFFICE_DEVICE_ID
        key: $TIDBYT_OFFICE_KEY

   2. Find your Device ID and Key in the Tidbyt mobile app under Settings > General > Get API Key.

   3. Add the TIDBYT_<NAME>_DEVICE_ID and TIDBYT_<NAME>_KEY environment variables in .env. For example:

      TIDBYT_OFFICE_DEVICE_ID="foo-bar-baz-qux-abc"
      TIDBYT_OFFICE_KEY="<key>"

3. Add your apps

The most important files in your Pixbyt repo (and likely the only ones you'll want to edit) are the following, which define the apps, their configuration, and their apps:

pixbyt
├─ .env                     # Configuration
├─ apps.yml                 # App schedules
├─ devices.yml              # Optional: Devices
└─ apps
   └─ <app>                 # One directory for each app
      ├─ <app>.star         # Main Pixlet applet
      ├─ pixbyt.yml         # Pixbyt metadata
      ├─ requirements.txt   # Optional: Python packages (one `pip install` argument per line)
      ├─ apt-packages.txt   # Optional: APT packages (one `apt-get install` argument per line)
      ├─ *.py               # Optional: Python scripts to run using `file.exec`
      ├─ *.star             # Optional: Starlark files to load using `load`
      └─ *                  # Optional: Files to read using `file.read`

Out of the box, Pixbyt comes with a single hello-world app that shows off some of its advanced features and can be used as an example to build your own.

If you're just trying out Pixbyt and don't yet have another app in mind that you'd like to run, you can keep hello-world and skip ahead to step 4 to build and launch the app server.

If you don't want hello-world on your Tidbyt, you can disable it by removing its entry from apps.yml (and .env), but DO NOT remove the apps/hello-world directory as the GitHub Actions workflow that builds the Docker image uses it to test if the image works.

3.1. Add an app

Option A: Use the example hello-world app

Skip ahead to step 4 to build and launch the app server.

Option B: Install an existing app

1. Add the app's repo as a submodule under apps:

   git submodule add https://github.com/<username>/<repository>.git apps/<app>

   For example, to install crossword:

   git submodule add https://github.com/DouweM/tidbyt-crossword.git apps/crossword

   Note that in this case, the repo is called tidbyt-crossword, but the app directory needs to be called crossword.

Option C: Create a brand-new app

1. Create a new directory for your app under apps, and enter the new directory:

   cd apps
   mkdir <app>
   cd <app>

2. Create the main applet at apps/<app>/<app>.star.

   Any standard Pixlet applet is supported, as well as all Pixlib features.

   Note that the app directory and file names need to match.

   Optionally, your app directory can also contain:

   • *.py scripts to run using file.exec
   • *.star files to load using load
   • arbitrary files to read using file.read
   • Python packages in requirements.txt (one pip install argument per line)
   • APT packages in apt-packages.txt(one apt-get install argument per line)

3. Create the Pixbyt metadata file at apps/<app>/pixbyt.yml:

   jobs:
   - name: <app>
     tasks:
     - tap-pixlet--<app> target-tidbyt
   - name: <app>--webp
     tasks:
     - tap-pixlet--<app> target-webp
   
   plugins:
     extractors:
     - name: tap-pixlet--<app>
       inherit_from: tap-pixlet
       # TODO: If your app does not have a `requirements.txt` defining Python packages, delete the following line:
       pip_url: git+https://github.com/DouweM/tap-pixlet.git -r apps/<app>/requirements.txt
       config:
         path: apps/<app>
         # TODO: If your app does not require configuration, delete the following lines:
         app_config:
           # TODO: For any key your app reads from `config`, add an entry mapping the lowercase key to an uppercase environment variable, e.g. `name: $HELLO_WORLD_NAME`:
           <key>: $<APP>_<KEY>

   Most of this is boilerplate for Meltano, you only need to make the following changes:

   1. Replace <app> with the name of your app
   2. Follow the TODO instructions.

3.2. Configure the app

1. Add the app and its update schedule to apps.yml under apps::

   apps:
   # ...
   - name: <app>
     schedule: '<cron expression>'
     # If you have multiple Tidbyts defined in `devices.yml`, you can optionally filter them by name:
     # devices: [<device>]

   1. Replace <app> with the name of the app.

   2. Replace <cron expression> with an appropriate cron expression:

      • Clocks should use * * * * * to update every minute, so that the displayed time is always as fresh as possible.
      • Apps that display a random entry from a list can use */5 * * * * to update every 5 minutes, so that a fresh entry is shown on every app rotation.
      • Apps that show the latest data from some API can use */15 * * * * to update every 15 minutes, or something else appropriate for your data source and the expected data freshness.
      • Apps that will always generate the same image can use 0 0 * * * to update every day at midnight, just to be sure.

      A recommended schedule is typically documented in the app's README.

   3. Optionally, replace <device> with the name of a device defined in devices.yml to only send the app to that device. By default, the app will be sent to all devices.

   For example:

   apps:
   # ...
   - name: hello-world
     schedule: '0/15 * * * *' # Every 15 minutes
     devices: [office] # Optional

   Note that examples in apps' READMEs sometimes use schedules and interval keys instead of apps and schedules. They are equivalent and both are supported, but the latter is preferred.

2. If the app requires configuration, add its environment variables to .env:

   For any config key the app defines under app_config: in its pixbyt.yml file, add a value for the uppercase environment variable:

   <APP>_<KEY>="<value>"

   The exact environment variables are typically documented in the app's README.

   For example:

   HELLO_WORLD_NAME="world"

3.3 Test the app

If you're developing a new app, or you're not confident you've configured it correctly, you can test it without building and running the entire app server by following the Development instructions below.

4. Build the app server

To be able to easily run your app server using Docker Compose, you will build a Docker image from your repo containing Pixbyt and your apps.

Option A: Build using GitHub Actions

1. Edit docker-compose.yml:

   1. Under x-remote-image:, replace <username> with your GitHub username
   2. Under pixbyt:, comment out <<: *local-image and uncomment <<: *remote-image on the next line

2. Commit your changes:

   git add -A
   git commit -m "Set up my Pixbyt"

3. Push your repo up to GitHub:

   git push origin main

   This will automatically trigger a GitHub Actions workflow to build a Docker image containing Pixbyt and your apps whenever your apps or their schedules change.

Option B: Build locally

Note that you'll need to do this each time your apps or their schedules change.

1. Ensure Docker is installed.

Note that Docker is not available in GitHub Codespaces. If you've opened your Pixbyt repo in GitHub Codespaces, use the GitHub Actions method above instead.

1. Build a Docker image containing Pixbyt and your apps:

   docker compose build

5. Launch the app server

During testing and development, you can do this on your local machine. In production, you'll likely want to do this on a NAS or other homelab, or on any other (virtual) server that has access to the required network resources.

Note that you'll need to do this each time your apps or their schedules change and a new Docker image is built, or whenever their configurations change.

1. Ensure Docker is installed.

2. If you chose to build your Docker image using GitHub Actions in the previous step, authenticate with the GitHub Container Registry.

3. Create or update .env with your configuration, based on the sample or the configuration you used during development.

4. Launch Pixbyt using Docker Compose:

   docker compose up --pull --build -d

Your Pixbyt app server is now running, and your apps will update on schedule! You can find logs for your apps under logs/apps/<app>/.

How to develop apps with Pixbyt

During app development or debugging, you will not want to build the entire Docker image each time your apps, their schedules, or their configurations change, nor will you want to run the entire app server.

Instead, you can directly render a specific app to a WebP image file or your Tidbyt, and quickly iterate on your app based on what you see in the logs and the output image.

Set up development environment

Option A: GitHub Codespaces

The quickest way to start developing is using GitHub Codespaces, which will automatically install the necessary dependencies and launch you into a web-based VS Code editor.

If you're already inside a codespace, continue to the next step.

If you've already created your own repo using this template repo:

1. Click the "<> Code" button at the top of the page
2. Choose "Codespaces" > "Create codespace on main"

If you haven't created a new repo from this template yet:

1. Click the green "Use this template" button at the top of this page
2. Choose "Open in a codespace"

Option B: Develop locally

1. Install Pixlet:

   • On macOS:

     brew install tidbyt/tidbyt/pixlet

   • Other operating systems

2. Install Meltano:

   • With pip:

     pip install meltano

   • Other installation methods

3. If your project contains apps as submodules, initialize them:

   git submodule update --init

4. Manually install any APT packages defined in your apps' apt-packages.txt files.

5. Install tap-pixlet, target-tidbyt, and target-webp using Meltano:

   meltano install

Option C: Docker image

If you've already built a Docker image and want to test the apps inside it without making changes to them, you can use the docker compose commands below.

Render app to a WebP image file

The image will be created at output/<app>/<timestamp>.webp. The exact path is also printed in the command output.

Regular size (64x32)

meltano run <app>--webp

# Using Docker image:
docker compose run pixbyt run <app>--webp

For example:

meltano run hello-world--webp

# Using Docker image:
docker compose run pixbyt run hello-world--webp

Magnified 8 times (512x256)

TAP_PIXLET_MAGNIFICATION=8 meltano run <app>--webp

# Using Docker image:
docker compose run -e TAP_PIXLET_MAGNIFICATION=8 pixbyt run <app>--webp

For example:

TAP_PIXLET_MAGNIFICATION=8 meltano run hello-world--webp

# Using Docker image:
docker compose run -e TAP_PIXLET_MAGNIFICATION=8 pixbyt run hello-world--webp

Render app to your Tidbyt

Send to foreground

The app will immediately show up on your Tidbyt. This is useful during development.

TAP_PIXLET_BACKGROUND=false meltano run <app>

# Using Docker image:
docker compose run -e TAP_PIXLET_BACKGROUND=false pixbyt run <app>

For example:

TAP_PIXLET_BACKGROUND=false meltano run hello-world

# Using Docker image:
docker compose run -e TAP_PIXLET_BACKGROUND=false pixbyt run hello-world

Send to background

The app will be added to the Tidbyt app rotation. This is useful when you're running this command on a schedule, to make sure that the app will be up to date the next time it comes up in the app rotation.

meltano run <app>

# Using Docker image:
docker compose run pixbyt run <app>

For example:

meltano run hello-world

# Using Docker image:
docker compose run pixbyt run hello-world

Keep apps up to date

If you're working with Pixbyt in GitHub Codespaces or locally, you can quickly iterate on apps and test your changes (this is not possible when you're debugging inside a Docker container). Changes to an app's source files are automatically picked up, but changes to APT and Python package dependencies aren't.

If an app defines Python packages in its requirements.txt file, you'll need to manually do a clean install of the app's Meltano plugin every time it changes:

meltano install --clean extractor tap-pixlet--<app>

For example:

meltano install --clean extractor tap-pixlet--hello-world

If an app defines APT packages in its apt-packages.txt file, you'll need to manually install them every time they change.