Read-only Trello connector for Claude (claude.ai/design)

A tiny remote MCP server that lets Claude on the web read your Trello boards, lists, and cards. There is no official Trello connector, so this fills the gap. It is read-only — it cannot change anything in Trello.

Once deployed you add it under Settings → Connectors → Add custom connector in Claude, and then Claude (including claude.ai/design) can pull your cards.

Tools it exposes

Tool	What it does
list_boards	Your open boards (id, name, URL)
list_lists	Lists/columns on a board
list_cards	Cards on a board, or in one list
get_card	Full card detail: description, labels, due, members, checklists, comments, attachment links
search_cards	Find cards by keyword (whole account or one board)

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Step 1 — Get your Trello credentials (read-only)

1. API key: go to https://trello.com/app-key while logged in and copy the Key. (You may be asked to create a Power-Up first — name it anything, e.g. "Claude reader"; that's just how Trello issues a key now.)

2. Read-only token: open this URL in your browser, replacing YOUR_KEY, then click Allow:

   https://trello.com/1/authorize?expiration=never&name=ClaudeTrello&scope=read&response_type=token&key=YOUR_KEY
   

   scope=read means the token can only read — even if the URL leaked, no one could edit your boards with it. Copy the token Trello shows you.

Keep the Key and Token handy for Step 3.

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Step 2 — Deploy the server (no local install needed)

The simplest path uses Render's free tier and builds everything in the cloud, so you don't need Node or a newer Python on your Mac.

1. Put this folder on GitHub (a private repo is fine). If you have the gh CLI:

   git init && git add -A && git commit -m "Trello MCP connector"
   gh repo create trello-mcp --private --source=. --push
   

   (Or create a repo in the GitHub web UI and upload these files.)
2. Go to https://render.com → New + → Blueprint → pick the repo. Render reads render.yaml and sets up a Python 3.11 web service automatically.
3. When prompted (or under the service's Environment tab) set:
   • TRELLO_API_KEY → your key from Step 1
   • TRELLO_TOKEN → your read-only token from Step 1
   • MCP_PATH → an unguessable path, e.g. /mcp-7f3a9c2e1b (make up your own)
4. Deploy. Render gives you a URL like https://trello-mcp-xxxx.onrender.com.

Your MCP endpoint is that URL plus your MCP_PATH, e.g. https://trello-mcp-xxxx.onrender.com/mcp-7f3a9c2e1b.

Heads-up on Render free tier: the service sleeps after inactivity, so the first request after a pause takes ~30–60s to wake. Fine for occasional use.

Prefer containers? A Dockerfile is included — deploy it to Fly.io, Railway, Cloud Run, or your own VPS instead. Same env vars apply.

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Step 3 — Add it to Claude

1. In Claude (web): Settings → Connectors → Add custom connector.
2. Paste your full MCP endpoint URL (URL + MCP_PATH from Step 2).
3. Save. Claude will connect and discover the five tools above.

Now in claude.ai/design you can say things like "list my Trello boards", "pull the cards from the 'Launch' list on my Marketing board", or "search my Trello for cards mentioning rebrand" — and use them in your design work.

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Security — read this

In this simple setup, the URL is the only thing protecting your data: anyone who has the full URL (including MCP_PATH) can read your Trello. That's why:

• MCP_PATH must be long and random — treat the full URL like a password.
• The Trello token is scope=read, so a leak can't modify your boards.
• Don't paste the URL into shared docs, screenshots, or chats.

Want stronger protection? The proper hardening is OAuth on the connector (FastMCP supports it), so Claude authenticates instead of relying on a secret URL. That's a worthwhile upgrade if this holds sensitive boards — say the word and I'll wire it in.

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Running locally (optional)

Requires Python 3.10+ (your system Python is 3.9, so use a newer one, e.g. via pyenv or brew install python@3.11):

python3.11 -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt
cp .env.example .env   # fill in your key/token
set -a && source .env && set +a
python trello_mcp_server.py

The endpoint will be at http://localhost:8000$MCP_PATH. Local HTTP can't be added to claude.ai (it needs public HTTPS) — local runs are just for testing, e.g. with the MCP Inspector (npx @modelcontextprotocol/inspector).