Moxfield MCP Server

A local MCP server that gives Claude access to Moxfield's deckbuilding platform data — public deck search, deck card lists, and card prices.

Moxfield has no official public API. This server calls the same JSON endpoints (api2.moxfield.com) that moxfield.com's own frontend uses. These endpoints are undocumented and unofficial — they may change or break without notice. No API key is needed; requests include browser-like headers to satisfy Cloudflare.

Tools

• moxfield_search_decks — search public decklists by keyword, optionally filtered by format; returns deck names, authors, like/view counts, and URLs
• moxfield_get_deck — fetch a specific deck's full card list (commanders, mainboard, sideboard) with mana costs, type lines, and per-card USD prices
• moxfield_search_cards — search Moxfield's card database by name or keyword, returning oracle text, legalities, and prices from multiple vendors

Setup

1. Install dependencies

Requires Python 3.10+.

cd "moxfield_mcp"
pip install -r requirements.txt

2. Test it directly (optional)

python server.py

With no PORT environment variable set, this runs over stdio (for the MCP Inspector or a classic Claude Desktop config). You can also exercise it with the MCP Inspector:

npx @modelcontextprotocol/inspector python server.py

3. Register it as a connector in Cowork (this project)

Cowork's "Add custom connector" dialog only accepts a remote MCP server URL — it can't point at a local script. server.py runs over streamable-HTTP automatically whenever a PORT environment variable is present (which is how Render and most PaaS hosts tell an app what to bind to). That's what makes it deployable.

Deploy to Render (free tier):

1. Push the contents of this moxfield-mcp folder to a new GitHub repo (the folder's contents should be the repo root — server.py, requirements.txt, and render.yaml at the top level).

   cd "moxfield-mcp"
   git init
   git add .
   git commit -m "Moxfield MCP server"
   git branch -M main
   git remote add origin https://github.com/<your-username>/moxfield-mcp.git
   git push -u origin main
   

2. Go to render.com → sign in with GitHub → New → Blueprint → select your moxfield-mcp repo. Render will read render.yaml and configure the service automatically. Click Apply.
3. Wait for the first deploy to finish (a few minutes). Render gives you a URL like https://moxfield-mcp.onrender.com.
4. Sanity-check it's alive by visiting https://moxfield-mcp.onrender.com/mcp in a browser — a 4xx/JSON error about missing headers is fine; that means the MCP endpoint is up.
5. In Cowork, open Settings → Connectors → Add custom connector, and paste:
   • Name: Moxfield (or anything you like)
   • Remote MCP server URL: https://moxfield-mcp.onrender.com/mcp
   • Leave Advanced settings (OAuth) blank — this server has no auth.
6. Save. The Moxfield tools should now show up as a connector you can enable in any conversation.

Note on the free tier: Render's free web services spin down after ~15 minutes of inactivity and take 30-60 seconds to wake back up on the next request (cold start).

Notes

• Moxfield's API is Cloudflare-protected. This server mimics browser headers to bypass the bot check — this may break if Moxfield changes their Cloudflare configuration.
• Private/unlisted decks will return a 404 error; only public decks are accessible without authentication.
• Prices are Moxfield's aggregated vendor data and update daily.