Attention Button Backend

This is the backend implementation for the Attention Button, handling MQTT communication, authentication, and API requests. It is designed to run behind an Nginx instance that handles TLS termination.

Usage

Running the Backend

The server expects a config.json file in the current directory, but you can override this by setting the TAB_CONFIG_FILE environment variable.

TAB_CONFIG_FILE=/path/to/config.json node src/main.ts

Alternatively, for development mode:

TAB_ENV=dev node src/main.ts

You can also simply run nodemon to start a server with live-reloading.

Configuration

The configuration is defined as a JSON object and an example is given in config.example.json.

Required Fields:

• smtpHost: SMTP server hostname.
• smtpPort: SMTP server port.
• smtpUsername: SMTP authentication username.
• smtpPassword: SMTP authentication password.
• secrets: Array of secret keys used as the cookie secret.
• captchaSecret: Secret key for hCaptcha verification.

Optional Fields:

• hostname: Defaults to 0.0.0.0.
• httpPort: Defaults to 8000.
• smtpSecure: Whether to use secure SMTP (true for TLS, false for STARTTLS). Defaults to false.
• storeUrl: URL for the Attention Button store.
• mqttPort: Defaults to 1883.
• mqttTls: If true, additional fields keyPath, certPath, and caPath must be provided for TLS support.

Example for MQTT over TLS:

{
    "mqttTls": true,
    "keyPath": "/etc/ssl/private/mqtt.key",
    "certPath": "/etc/ssl/certs/mqtt.crt",
    "caPath": "/etc/ssl/certs/ca.pem"
}

Running Your Own Instance

The recommended setup is to run this backend behind an Nginx instance that handles HTTPS termination. Ensure that your Nginx configuration properly proxies requests to the backend.

Contributing

Contributions are welcome! If you find an issue or want to suggest improvements, feel free to open a pull request.

Hosted Instance

You can use the hosted instance at theattentionbutton.in.

Acknowledgements

This project uses the following libraries:

Acknowledgements

Acknowledgements

• aedes Copyright © 2015 Matteo Collina, The MIT License
• argon2 Copyright © 2015 Ranieri Althoff, The MIT License
• better-sqlite3 Copyright © 2016 Joshua Wise, The MIT License
• better-sqlite3-session-store Copyright © 2020 Tim Daubenschütz, GPL-3.0-only
• cors Copyright © 2013 Troy Goode, The MIT License
• escape-html Copyright © 2012 component, The MIT License
• express Copyright © 2010 TJ Holowaychuk, The MIT License
• express-rate-limit Copyright © 2014 Nathan Friedly, The MIT License
• express-session Copyright © 2014 TJ Holowaychuk, The MIT License
• hcaptcha Copyright © 2018 Juho Hautala, The MIT License
• http-status-codes Copyright © 2013 Bryce Neal, The MIT License
• kysely Copyright © 2021 Sami Koskimäki, The MIT License
• liquidjs Copyright © 2017 Harttle, The MIT License
• nodemailer Copyright © 2011 Andris Reinman, The MIT-0 License
• nodemailer-smtp-transport Copyright © 2014 Andris Reinman, The MIT License
• random-words Copyright © 2013 Apostrophe Technologies, The MIT License
• zod Copyright © 2020 Colin McDonnell, The MIT License
• zod-validation-error Copyright © 2022 Dimitrios C. Michalakos, The MIT License

License

MIT License. See LICENSE for details.