Introducing Cartheca Alpha: A Workshop for Your Next Bad Idea

Every Magic player has a deck idea that probably shouldn’t work.

A commander nobody at the table remembers. A combo with one too many moving parts. A pile of cards that has been “almost finished” for six months.

Cartheca is a place to work on those ideas—and the good ones, too.

Built by JankyJoes, Cartheca brings deckbuilding, collection tracking, and a playtest table into one free, fan-made workspace. With the Alpha version, we’re inviting you to try it, put your own decks through it, and help shape what comes next.

Why we built it

Cartheca grew out of two frustrations.

The first was watching friends spend too much of an evening getting a playtest table ready to share over a call. Showing the battlefield while keeping a hand private should be straightforward, and your setup should still be there when you come back.

The second was asking an AI assistant for deckbuilding advice and realizing how little of the picture it could see. A pasted decklist is useful, but it leaves out your other decks, your collection, and the cards you keep coming back to.

We wanted a workshop that could support both: somewhere to build and playtest, with a way to give a connected assistant more useful context when you want its help.

What you can do in Alpha

Build and organize your decks. Search for cards, import an existing list, sort decks into folders, assign cards multiple roles, and write a primer explaining how the deck works. Legality guidance helps you spot problems while leaving room for unfinished lists and kitchen-table experiments.

Keep track of your collection. Record the specific printings you own and their quantities, browse set checklists, and bring that information into your deckbuilding.

Take a deck to the table. The manual playtester includes drag-and-drop zones, tokens, counters, library actions, and undo. A separate Streamer View lets you share the table while keeping your hand and face-down cards concealed.

Share when you’re ready. Keep a deck private, send someone an unlisted link, or publish a legal deck to Community. You can also explore public lists and make a private copy to start your own version.

Bring your own AI assistant. Connect a supported assistant to work with the decks and collection you give it permission to access. Assistant changes to decks appear as proposals for you to review and approve. You stay in control of the list.

Cartheca also works on its own. Connecting an assistant is optional.

Alpha means we need your feedback

There’s enough here to start building, but there’s still work to do.

We want to hear where you get stuck, what feels awkward, and what’s missing from your usual routine. Import a deck you know well. Try tracking a few favorite printings. Take a brew through the playtester.

When something goes wrong, tell us what you were trying to do and what happened. That context helps us make Cartheca better.

Cartheca is free, with no paid tier and no plans for one.

Bring your favorite deck—or the idea you haven’t quite made work yet.

Let’s see what it can become.