Use any card's art as a deck sleeve

[MostCromulent]

What it does

Select any card's art as a deck sleeve. You pick a card from a dialog; chosen art renders in the lobby and in-match exactly where the built-in sleeves do, styled to match them, on both desktop and mobile.

How it works

A player's sleeve is stored as either a built-in sleeve index or a card image key, carried on LobbyPlayer/Player/PlayerView and exposed as a TrackableProperty so opponents see the choice; it travels over the wire in UpdateLobbyPlayerEvent.

Two preferences persist the choice across sessions: UI_SLEEVE_ART_LIBRARY holds the saved "Card Art Sleeves" library, and UI_SLEEVE_ART_KEYS holds the per-lobby-slot selection — sitting parallel to the existing UI_SLEEVES (built-in index per slot), so a slot using card art stores its key here while choosing a built-in sleeve clears it. Both are stored as comma-joined, URL-safe-base64-encoded image keys so card identifiers stay valid in the KEY=VALUE preference format.

The art itself comes from Scryfall's art_crop:

• When a card-art sleeve is needed, the existing Scryfall image fetcher is reused but forced to the art_crop variant (Scryfall's tightly-cropped artwork), regardless of the user's UI_CARD_ART_FORMAT preference. It's gated behind the online-image-fetcher preference and skips cards with no usable art_crop (custom cards, or those missing an artist / collector number).
• The download is cached under a dedicated sleeves cache (CACHE_SLEEVE_PICS_DIR), keyed by a hash of the image key with an .artcrop.jpg filename — chosen so the fetcher's Scryfall URL rewriting leaves it as the art_crop image.
• At render time the cached art_crop is centre-cropped to the built-in sleeve aspect and framed. The fetch is async — until the art lands, the built-in sleeve shows in its place.

Safety

The only thing sent over the network is a card image key (a card identifier) — never a URL or an image file. Each client independently derives the Scryfall art_crop from that key through its own preference-gated fetch path, so a player cannot point opponents at an arbitrary URL or push image bytes to them; an unrecognised key simply falls back to the built-in sleeve.

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🤖 Generated with Claude Code

[MostCromulent]

Since this just uses a card identifier to fetch the relevant scryfall art, it opens up some fun design space for future development: e.g. Adventure Mode enemies could have an optional field to use a specific card's art as their sleeve / player decks could designate sleeve art as metadata.