Typst Bot

A Discord bot that renders Typst code.

Built with poise so it has all the goodies like edit tracking, typing status, and automatic help generation.

Hosting

The bot uses two binaries:

• bot: connects to Discord and processes messages
• worker: receives requests, interacts with Typst, responds

bot will automatically spawn worker, so you only need to run bot.

To set up the working environment, create a directory with the following items:

• worker: The worker binary, copied/hardlinked from the target directory after building. If you put the worker somewhere else, you can set TYPST_BOT_WORKER_PATH to it.
• bot: The bot binary, copied/hardlinked from the target directory after building. (This doesn't need to be in this directory, but having everything in one place simplifies things.)
• db.sqlite: You can just touch this, but the bot needs to be able to write to it. (Legacy note: you don't need fonts anymore because we use typst-assets now.)

To run, CD into this directory, set DISCORD_TOKEN to your bot token, set CACHE_DIRECTORY and DB_PATH to suitable locations, and run the bot binary (not the worker binary that's also in the directory).

Docker

There is a Dockerfile and docker-compose.yml for running the bot inside a Docker container.

To set up the bot with Docker, create a discord_token.txt file containing your bot token and start the container with docker compose up -d.

Public Instance

Here is a link you can use to invite a public instance run by @frozolotl: https://discord.com/oauth2/authorize?client_id=1183804211264225301&permissions=3072&scope=bot

Note: the bot may be limited from joining more servers because we require the message content (since slash commands don't support code blocks) and Discord denied verification, so we are limited to 100 servers. Accordingly, we request that you remove the bot from your servers if you are not using it anymore.

Is it safe to host? Is it true that Typst allows arbitrary code execution?

Typst is fundamentally a sandboxed, interpreted language so there is no such thing as "arbitrary code execution". However, Typst documents/code can access the host environment in a limited capacity. In CLI usage, documents can read files (e.g., images) inside the project directory and download packages from the typst packages repo. For the bot, only the latter is allowed. Resource exhaustion and DOS attacks are also somewhat addressed with timeouts and automatic restarting on crash. If you are paranoid, I suggest to set up adequate sandboxing on the host (which you should do for everything anyway) -- for example with Docker or systemd sandboxing.

License

AGPL. Use ?source to get a link to the source from deployments of the bot.