Lorcana MCP

Disney Lorcana MCP Server

An MCP server that lets Claude (or any MCP client) search, analyze, and build decks for the Disney Lorcana TCG. Ask for cards in plain English, get rules-checked deck validation, ink curves and keyword breakdowns, and round-trip deck lists with Dreamborn/Pixelborn.

2,506 unique cards (3,192 printings including alternate arts and promos), refreshed daily. No API key, no database, no rate limits — the server ships against a snapshot published from our own pipeline, so it never depends on a third-party API being up at query time.

Tools

Tool	What it does
search_cards	Filter and retrieve cards by name, color, cost, rarity, type, keyword, stats, set, and body text. Supports response_format="toon" for ~10% fewer tokens
count_cards	Count cards matching a filter without paying for the card objects
aggregate_cards	Group counts by cost (ink curve), rarity, color, set_code, or type
resolve_card	Fuzzy-match an informal, partial, or misspelled card name to the closest cards
top_traits	Most common traits (Storyborn, Hero, Villain, Ally, ...) across all cards
validate_deck	Check a deck against format rules (≥60 cards, max 4 copies, ≤2 inks, dual-ink requirements); returns {legal, total_cards, inks, violations}
deck_stats	Ink curve, color split, inkable count, type breakdown, keyword counts, subtype counts, and per-card keyword tags
import_deck	Parse a Dreamborn/Pixelborn deck list into resolved cards, with fuzzy candidates for unresolved lines
export_deck	Render a deck back out as a Dreamborn/Pixelborn-compatible text list
server_status	Startup metadata (card count, configuration)

Install

uvx (recommended — no clone, no Docker)

uvx lorcana-cards-mcp

Claude Desktop / claude_desktop_config.json:

{
  "mcpServers": {
    "lorcana": {
      "command": "uvx",
      "args": ["lorcana-cards-mcp"]
    }
  }
}

Claude CLI:

claude mcp add --scope user -- lorcana uvx lorcana-cards-mcp

pip / pipx

pipx install lorcana-cards-mcp   # then run: lorcana-cards-mcp

Docker

The server is also published to GHCR and the MCP Registry.

docker run --rm -i ghcr.io/danielenricocahall/lorcana-mcp:latest

{
  "mcpServers": {
    "lorcana": {
      "command": "docker",
      "args": ["run", "--rm", "-i", "ghcr.io/danielenricocahall/lorcana-mcp:latest"]
    }
  }
}

To persist the card cache across container restarts, mount a volume:

docker run --rm -i \
  -e LORCANA_CACHE_PATH=/data/cards.json \
  -e LORCANA_SKIP_IF_DB_EXISTS=true \
  -v lorcana_mcp_data:/data \
  ghcr.io/danielenricocahall/lorcana-mcp:latest

From a clone

uv run python main.py

docker build -t lorcana-mcp:latest .
docker run --rm -i lorcana-mcp:latest

# or via compose
docker compose build
docker compose run --rm -T lorcana-mcp

No port is exposed; MCP communication is over stdio.

Example questions

Once connected to an MCP client, you can ask natural language questions like:

Card lookup

• "Show me all cards named Moana"
• "What does the card Maui - Hero to All do?"
• "Find all legendary amber cards"

Deck building

• "What are the cheapest ruby characters with at least 3 strength?"
• "Show me inkable sapphire cards that cost 4 or less"
• "Find steel characters with 5 or more willpower"
• "What 3-lore characters exist in emerald?"

Keyword & ability search

• "How many Singer cards cost exactly 5?"
• "How many Evasive characters are there in the first set?"
• "How many ruby cards have Reckless?"
• "Find all cards with Ward in their text"
• "Show me Shift cards in amethyst"

Stats & aggregations

• "How many cards are in each set?"
• "What's the color distribution across all cards?"
• "What are the most common traits?"
• "Show me the ink curve — how many cards exist at each cost?"
• "How many legendary cards are inkable?"

Cross-filter queries

• "How many amber characters have 3 or more lore?"
• "Find cheap (cost 2-3) characters with high strength (4+) in steel"
• "How many cards in set 1 have Evasive and cost less than 4?"

Note: For plain keyword queries (Evasive, Bodyguard, Shift, etc.) use the keyword parameter — it filters against the structured ability list and is more reliable than substring search. For value-specific queries like Singer 5 or Resist +2, use body_text (keyword values live in the card's full text, not the ability list).

MCP prompts

• build_deck(colors, playstyle="balanced") — guides the model through assembling a legal Lorcana deck (60-card minimum, ≤2 inks, max 4 copies of any card) for the requested color(s) and playstyle (aggressive / control / lore-race / balanced). Uses the search/aggregate tools above plus the rules embedded in the server instructions.

Card data & startup behavior

On startup, the server fetches a JSON list of cards from https://danielenricocahall.github.io/lorcana-mcp/allCards.json. The snapshot is refreshed daily by data_pipeline/fetch_cards.py, which pulls from the Lorcast API, normalizes each card into our internal schema, and publishes the list to the gh-pages branch. That middle layer insulates running servers from Lorcast's availability and rate limits — the runtime never calls Lorcast directly.

Cards are kept in memory as a Python list for fast filtering. The dataset holds 2,506 unique cards, each carrying a printings array for its alternate sets, numbers, and rarities (3,192 printings in total). Consolidating printings onto one row per card means a search for "Elsa" returns each distinct Elsa once rather than repeating her for every promo reprint. A local JSON file cache (LORCANA_CACHE_PATH, default cards.json) lets the server skip the network fetch on subsequent startups.

Config

• LORCANA_API (default: https://danielenricocahall.github.io/lorcana-mcp/allCards.json)
• LORCANA_CACHE_PATH (default: cards.json) — local file for caching fetched cards
• LORCANA_HTTP_TIMEOUT_SECONDS (default: 60)
• LORCANA_REFRESH_ON_STARTUP (default: false) — true always fetches and repopulates storage
• LORCANA_SKIP_IF_DB_EXISTS (default: true) — false fetches and repopulates even if the cache is populated

TOON response format

search_cards accepts a response_format argument:

• "json" (default) — list of card objects, unchanged from prior versions.
• "toon" — a TOON string with one column header line and one row per card, encoded by the toons Rust-backed library (the official community reference implementation).

Example (search_cards(name="elsa", limit=2, response_format="toon")):

cards[2]:
  - id: crd_01c4835a62df4960bb973aeff81f2bb2
    name: Elsa
    version: Ice Maker
    full_name: Elsa - Ice Maker
    cost: 7
    ...
    printings[3]{set_code,set_name,number,rarity}:
      "7",Archazia's Island,69,Super Rare
      C2,Lorcana Challenge Year 3,2,Promo
      C2,Lorcana Challenge Year 3,6,Promo
  - id: crd_04bca46a8e2d4e9ba0fbdbfc6c99e51e
    name: Elsa
    ...

The outer cards[2]: falls back to YAML-style per-card blocks (rather than a single tabular table) because card shapes vary — Actions and Items don't carry strength/willpower/lore, for example. The inner printings[N]{...}: block is fully tabular since every printing has the same four fields.

Benchmark

Measured with benchmarks/bench_toon.py against the live 2,506-card dataset, tokenizing with tiktoken cl100k_base (used as a proxy for Claude's tokenizer):

query	rows	JSON tokens	TOON tokens	Δ
color="amber", limit=200	200	44,101	39,680	−10.0%
color="ruby", limit=50	50	10,522	9,519	−9.5%
card_type="action", limit=50 (sparse cols)	50	10,154	9,250	−8.9%
body_text="when", limit=50 (long full_text)	50	11,602	10,391	−10.4%
name="elsa", limit=20	14	3,488	2,940	−15.7%
total		79,867	71,780	−10.1%

Note: TOON's relative savings are smaller here than they were before the printings consolidation (pre-PR-#29 the same queries showed ~50% reductions). That gap is structural to the nested printings array — TOON's columnar encoding wins on the top-level fields but falls back to JSON-style encoding inside the per-printing entries, so the array dilutes the relative gain. Absolute token counts are still down meaningfully versus the equivalent count of pre-consolidation rows, since each unique card is now represented once with a small printings list rather than as 1-3 separate full rows.

Reproduce with PYTHONPATH=. uv run python benchmarks/bench_toon.py (requires a populated cards.json cache).

Disclaimer

This is a personal, unofficial fan and engineering project. It is not affiliated with, endorsed by, sponsored by, or reviewed by Disney, Ravensburger, or the Disney Lorcana TCG team. It is built and distributed in accordance with Ravensburger's Disney Lorcana TCG Community Code, using only publicly available and community data sources. All Disney Lorcana TCG names, card text, trademarks, and related intellectual property belong to Disney and Ravensburger. This project is non-commercial and reflects my personal views only, not those of my employer.

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_{MCP Registry ownership verification — the registry reads this line from the published package description to confirm this project owns the server name.}

mcp-name: io.github.danielenricocahall/lorcana-mcp