satorntcg-mcp-server

An MCP server that exposes live TCG resale/inventory data — pricing, alerts, profit & loss, eBay listings — as tools an LLM client (Claude Desktop, Claude Code, etc.) can call directly. Instead of opening a dashboard, you can just ask: "what's underpriced right now" or "how is the Gothic box performing" and get an answer grounded in real data.

Built on top of SatornTCG, a Sorcery: Contested Realm resale/content operation backed by Supabase/Postgres.

Why this exists

This started as a resume project to learn MCP server design and observability, and turned into a tool I actually use day to day to query my own inventory and pricing data conversationally instead of clicking through a UI.

Related MCP server: mcp-ygoprodeck

What it exposes

Each tool is a thin wrapper around a Postgres view — see src/tools/.

Architecture

Claude Desktop / Claude Code (MCP client)
        │  stdio
        ▼
  src/index.js  ── registers tools, routes tool calls
        │
        ▼
  src/tools/*.js ── one file per domain, each tool = { name, description, inputSchema, handler }
        │
        ▼
  src/supabaseClient.js ── service-role Supabase client
        │
        ▼
  Postgres (Supabase) ── views: v_active_alerts, v_inventory_dashboard,
                          v_latest_prices, v_box_pnl, v_global_pnl,
                          v_ebay_active, v_ebay_sold, v_stale_listings,
                          v_price_gainers_losers, v_listing_price_alerts

Observability via OpenTelemetry (tracing tool calls end-to-end, exported to Jaeger) is planned — see src/tracing.js for the stub and activation notes.

Schema this expects

This server doesn't ship a demo database — it's meant to be pointed at a Postgres/Supabase project with equivalent views. If you're adapting this for your own data, the views above are just SELECTs over your own tables; swap the query in each src/tools/*.js file to match your schema. Column names referenced directly (e.g. card_id, name, tcg_market_price, cost_basis, dismissed) are the main thing to line up.

Setup

git clone <this-repo>
cd satorntcg-mcp-server
npm install
cp .env.example .env
# fill in SUPABASE_URL and SUPABASE_SERVICE_KEY in .env
npm start

The server speaks MCP over stdio, so it's meant to be launched by an MCP client, not run standalone in a terminal for interactive use. To test with Claude Desktop, add it to your MCP config (claude_desktop_config.json):

{
  "mcpServers": {
    "satorntcg": {
      "command": "node",
      "args": ["/absolute/path/to/satorntcg-mcp-server/src/index.js"]
    }
  }
}

Restart Claude Desktop, and the tools above become available in conversation.

Security note

SUPABASE_SERVICE_KEY is the elevated service-role key, not the public anon key. This is safe here because the server only ever runs as a local process launched by a trusted MCP client (never in a browser bundle) — the same reasoning as using a service role key inside a Supabase Edge Function. Never commit .env; only .env.example (placeholder values) is tracked.

Roadmap

• OpenTelemetry tracing per tool call (latency, row counts, error rate) → Jaeger locally, Honeycomb/Grafana for a hosted demo

• suggest_listing tool — draft an eBay listing from inventory + pricing data

• HTTP/SSE transport for remote access, alongside the local stdio transport

License

MIT — see LICENSE.