Open standard · v1 draft

One deck code for the whole community

Two open formats for the Palworld TCG: PWC. is a self-contained, URL-safe code that is the decklist; PWCS. is an ultra-short variant backed by a public card registry for character-limited environments. Full normative spec: docs/deck-code-standard.md in the repo.

The four artifacts

PWC portable code — decodable offline, ~100 lines, no server or card database required.
PWCS short code — same information in typically under ~80 characters, using dense integer card IDs from the public registry at /api/cards.json.
Share code — a 5–8 character key into a hosted deck page (/decks/ABC12), referenced as code:ABC12 in play URLs. Site-specific.
Text format — the human-readable interchange:

// Main Deck
4x ETD01-001
3x ETD01-014
2x BP01-001-SSP

// Soul Deck
10x ESOUL-001

PWC wire format

PWC. + base64url (no padding) of:

Offset	Field	Notes
0	version	0x01
1	metadata pair count K	u8; then K pairs of [key_len u8][key ASCII][val_len u8][val UTF-8]. Keys lowercase; e.g. name, author.
—	main entry count M	u8; then M entries of [count u8][len u8][ASCII card number], sorted lexicographically.
—	soul entry count S	u8; then S entries, same shape, sorted.
last	checksum	Sum of every preceding byte mod 256.

PWCS wire format

PWCS. + base64url (no padding). Card numbers are replaced by dense integer IDs from the registry manifest:

Offset	Field	Notes
0	version	0x01
1	registry generation	u8; must match your manifest's generation or reject.
2…	metadata pairs	varint count, then [key_len u8][key][val_len u8][val].
—	main deck groups	Four groups: [entry count varint] then delta-encoded LEB128 card ids for 1x, 2x, 3x, then N-copies pairs [count varint][id delta varint].
—	soul deck groups	Same four-group structure.
last	checksum	Sum of every preceding byte mod 256.

The registry (/api/cards.json) is append-only: an ID once assigned is never reassigned within a generation — old codes decode forever.
Encoders register new card numbers via POST /api/cards.json with { "cards": [...] } — returns the refreshed manifest, safe to call before every encode.
Delta-encoded card IDs MUST be sorted ascending so all deltas are positive.
Decoders MUST verify version, registry generation, bounds, and checksum — never partially decode.

Versioning

The version byte implies the payload layout: PWC. and PWCS. are both at 0x01. Future formats ship with a new version byte — reject unknown versions rather than guessing. Registry generation is versioned independently of payload version.

Already working on the site

Every public deck page exposes both a PWC and a PWCS code (with name/author metadata).
Builder import/export and the Import Code dialog accept PWC, PWCS, share codes, and text lists.
Play with — or against — a code directly: /play/local?deckId=PWC.…&bot=PWCS.…, or code:ABC12 for hosted decks. Pick them in Practice vs AI.
Card registry manifest: /api/cards.json

Deck names, lists, and votes are community content; card data belongs to Pocketpair, Inc. and Bushiroad Inc. These formats are offered for the whole unofficial ecosystem to share.