Anthias/website/content/docs/developer-documentation.md

---
title: "Developer Documentation"
description: "Develop and contribute to Anthias: architecture, services, building, and testing."
slug: "development"
aliases:
  - "/docs/developer-documentation/"
---

## Understanding the components that make up Anthias

Here is a high-level overview of the different components that make Anthias:

![Anthias Diagram Overview](/docs/d2/anthias-diagram-overview.svg)

These components and their dependencies are mostly installed and handled with Ansible and Docker.

* The **web app** component (`anthias-server`) is the single HTTP entrypoint, served by uvicorn (ASGI). It runs the Django front-end + REST API, serves static assets via WhiteNoise, streams uploaded media at `/anthias_assets/`, and exposes the WebSocket endpoint at `/ws` via Django Channels. Always plain HTTP — TLS is opt-in via the **anthias-caddy** sidecar that `bin/enable_ssl.sh` installs (Caddy local CA by default, or Let's Encrypt with `--domain`).
* The **viewer** (`anthias-viewer`) is what drives the screen (e.g., shows web page, image or video). It fetches media from `anthias-server` over HTTP.
* The **Celery** (`anthias-celery`) component is for asynchronously queueing and executing tasks outside the HTTP request-response cycle (e.g., yt-dlp downloads, asset cleanup). It pushes asset-update events to connected WebSocket clients via the Redis-backed Channels layer.
* **Redis** (`redis`) is used as the Celery broker/result backend and as the Channels channel layer.
* The **database** component uses **SQLite** for storing the assets information.

## Dockerized development environment

To simplify development of the server module of Anthias, we've created a Docker container. This is intended to run on your local machine with the Anthias repository mounted as a volume.

> **Important**
>
> * Make sure that you have [installed Docker](https://docs.docker.com/engine/install/) on your machine before proceeding.
> * Anthias is using Docker's [buildx](https://docs.docker.com/engine/reference/commandline/buildx/) for the image builds. This is used both for cross compilation as well as for local caching. You might need to run `docker buildx create --use` first.

Assuming you're in the source code repository, simply run:

```bash
$ ./bin/start_development_server.sh

# The console output was truncated for brevity.
# ...

[+] Running 4/4
 ✔ Network anthias_default                Created                            0.1s
 ✔ Container anthias-redis-1              Started                            0.2s
 ✔ Container anthias-anthias-server-1     Started                            0.3s
 ✔ Container anthias-anthias-celery-1     Started                            0.4s
```

> **Note**
>
> Running the script will install Python 3.11, [pyenv](https://github.com/pyenv/pyenv),
> and [uv](https://docs.astral.sh/uv/) inside a Docker container on your machine.
> This is to ensure that the development environment is consistent across different
> machines.
>
> The script currently supports Debian-based systems and macOS.

Running the command above will start the development server and you should be able to
access the web interface at `http://localhost:8000`.

To stop the development server, run the following:

```bash
docker compose -f docker-compose.dev.yml down
```

## Building containers on the Raspberry Pi

> **Note**
>
> Make sure that you have Docker installed on the device before proceeding.

```bash
$ ENVIRONMENT=production \
    ./bin/generate_dev_mode_dockerfiles.sh
$ MODE=build \
    ./bin/upgrade_containers.sh
```

## Django admin site

Create a superuser account:

```bash
$ export COMPOSE_FILE=docker-compose.dev.yml
$ docker compose exec anthias-server \
    python manage.py createsuperuser
# You will be prompted to enter a username, an email address, and a password.
```

Once you have created a superuser account, you can open the Django admin site at `http://localhost:8000/admin/` (with a trailing slash)
and login with the credentials you just created.


## Testing
### Running the unit tests

Build and start the containers.

```bash
$ uv run python -m tools.image_builder \
  --dockerfiles-only \
  --disable-cache-mounts \
  --service redis \
  --service test
$ docker compose \
    -f docker-compose.test.yml up -d --build
```

Run the unit tests.

```bash
$ docker compose \
    -f docker-compose.test.yml \
    exec anthias-test bash ./bin/prepare_test_environment.sh -s

# Integration and non-integration tests should be run separately as the
# former doesn't run as expected when run together with the latter.

$ docker compose \
    -f docker-compose.test.yml \
    exec anthias-test ./manage.py test --exclude-tag=integration

$ docker compose \
    -f docker-compose.test.yml \
    exec anthias-test ./manage.py test --tag=integration
```

### The QA checklist

We've also provided a [checklist](/docs/qa/) that can serve as a guide for testing Anthias manually.

## Generating CSS and JS files

To get started, you need to start the development server first. See this [section](#dockerized-development-environment)
for details.

### Starting the bundler in development mode

To start [Bun](https://bun.sh/) in development (watch) mode, run the following command:

```bash
$ docker compose -f docker-compose.dev.yml exec anthias-server \
    bun run dev
```

This runs `bun build --watch` for JS/TS and `sass --watch` for SCSS in parallel.
Making changes to the TypeScript, TSX, or SCSS files will automatically trigger a recompilation,
generating the corresponding bundle and CSS files.

### Formatting and linting TypeScript code

To run the linting and formatting checks on the TypeScript code, run the following command:

```bash
$ docker compose -f docker-compose.dev.yml exec anthias-server \
    bun run lint:check
$ docker compose -f docker-compose.dev.yml exec anthias-server \
    bun run format:check
```

If you want to fix the linting errors and formatting issues, run the following command:

```bash
$ docker compose -f docker-compose.dev.yml exec anthias-server \
    bun run lint:fix
$ docker compose -f docker-compose.dev.yml exec anthias-server \
    bun run format:fix
```

### Closing the transpiler

Just press `Ctrl-C` to close the bundler watch.

## Linting Python code locally

The project uses `ruff` for linting the Python codebase. While the linter is being run on the CI/CD pipeline,
you can also run it locally. There are several ways to do this.

### Run the linter using `act`

[`act`](https://nektosact.com/) lets you run GitHub Actions locally. This is useful for testing the CI/CD pipeline locally.
Installation instructions can be found [here](https://nektosact.com/installation/index.html).

After installing and setting up `act`, run the following command:

```bash
$ act -W .github/workflows/python-lint.yaml
```

The command above will run the linter on the all the Python files in the repository. If you want to run the linter
on a specific file, you can try the commands in the next section.

### Running the linter using `uv`

You have to install `uv` first. You can find the installation instructions
[here](https://docs.astral.sh/uv/getting-started/installation/).

After installing uv, run the following commands:

```bash
# Install the dependencies
$ uv venv
$ uv pip install --group dev-host
$ uv run ruff check .
```

To run the linter on a specific file, run the following command:

```bash
$ uv run ruff check /path/to/file.py
```


## Managing releases
### Creating a new release

Check what the latest release is:

```bash
$ git pull
$ git tag

# Running the `git tag` command should output something like this:
# 0.16
# ...
# v0.18.6
```

Create a new release:

```bash
$ git tag -a v0.18.7 -m "Test new automated disk images"
```

Push release:
```bash
$ git push origin v0.18.7
```

### Delete a broken release

```bash
$ git tag -d v0.18.5                         [±master ✓]
Deleted tag 'v0.18.5' (was 9b86c39)

$ git push --delete origin v0.18.5           [±master ✓]
```

## Directories and files explained

In this section, we'll explain the different directories and files that are
present in a Raspberry Pi with Anthias installed.

### `/home/${USER}/anthias/`

* All of the files and folders from the Github repo should be cloned into this directory.
* On installations created before the rename, this directory is `/home/${USER}/screenly/` — the installer migrates it to `anthias/` on upgrade and leaves a back-compat symlink at the old path for one release.

### `/home/${USER}/.anthias/`

* `default_assets.yml` — configuration file which contains the default assets that get added to the assets list if enabled
* `anthias.conf` — configuration file for web interface settings
* `anthias.db` – database file containing current assets information.
* On pre-rename installations this directory is `~/.screenly/` containing `screenly.conf` / `screenly.db`; the installer migrates them.


### `/etc/systemd/system/`

* `anthias-host-agent.service` — starts the Python script `host_agent.py`, which subscribes from the Redis component and performs a system call to shutdown or reboot the device when the message is received.

### `/etc/sudoers.d/anthias_overrides`

* `sudoers` configuration file that allows pi user to execute certain `sudo` commands without being a superuser (i.e., `root`)

### `/usr/share/plymouth/themes/anthias`

* `anthias.plymouth` — Plymouth config file (sets module name, `ImageDir` and `ScriptFile` dir)
* `anthias.script` – plymouth script file that loads and scales the splash screen image during the boot process
* `splashscreen.png` — the splash screen image that is displayed during the boot process

## Debugging the Anthias WebView

```
export QT_LOGGING_DEBUG=1
export QT_LOGGING_RULES="*.debug=true"
export QT_QPA_EGLFS_DEBUG=1
```

The Anthias WebView is a custom-built web browser based on the [Qt](https://www.qt.io/) toolkit framework.
The browser is assembled with a Dockerfile and built by a `src/anthias_webview/build_qt#.sh` script.

For further info on these files and more, visit the following link: [https://github.com/Screenly/Anthias/tree/master/src/anthias_webview](https://github.com/Screenly/Anthias/tree/master/src/anthias_webview)