What is mcpfortrello CLAUDE.md?

Development instructions for MCPforTrello, an open-source server that lets AI assistants connect to Trello, a tool for organizing work on boards and cards.

Use them when developing, testing, configuring, or deploying MCPforTrello, including setting its required secrets.

They document the server's architecture, development commands, OAuth login, encrypted credentials, and important project files.

How michaelpryor/mcpfortrello configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to michaelpryor/mcpfortrello. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/michaelpryor/mcpfortrello/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/michaelpryor/mcpfortrello

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/michaelpryor/mcpfortrello/claude-md/github.svg)](https://agentmods.dev/instructions/michaelpryor/mcpfortrello/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/michaelpryor/mcpfortrello/claude-md"><img src="https://agentmods.dev/badge/instructions/michaelpryor/mcpfortrello/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/michaelpryor/mcpfortrello/claude-md"><img src="https://agentmods.dev/badge/instructions/michaelpryor/mcpfortrello/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 490 This file is loaded in full into every session.

When invoked 490 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00490	$0.00490
Opus 5.5	$0.00196	$0.00196
Sonnet 5.5	$0.00098	$0.00098
Haiku 4.5	$0.00049	$0.00049

Measured 2mo ago against content hash a5b1aa55e618, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcpfortrello CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 53 lines

What it actually says

MCPforTrello

Public Trello MCP server at mcpfortrello.com. Open source (MIT).

Status: Trello shipped an official MCP server at https://mcp.trello.com/v1. The landing page in src/index.ts and the README direct users there by design — don't "fix" them back to promoting this server. This server still runs for existing connections; no shutdown date is set.

Architecture

Cloudflare Workers with @cloudflare/workers-oauth-provider for OAuth 2.1
McpAgent Durable Object from agents package for MCP sessions
OAuth 2.1 bridges to Trello's /1/authorize token flow
Trello credentials stored in encrypted OAuth grant props

Development

pnpm install
pnpm dev          # wrangler dev on localhost:8787
pnpm typecheck    # tsc --noEmit
pnpm test         # vitest
pnpm run deploy   # wrangler deploy — plain `pnpm deploy` hits pnpm's own subcommand and fails

Secrets

Stored in 1Password Claude vault, set via wrangler secret put:

TRELLO_API_KEY — from Trello Power-Up registration
COOKIE_ENCRYPTION_KEY — openssl rand -hex 32

Local development: copy .dev.vars.example to .dev.vars and fill in values.

Key Files

src/index.ts — OAuthProvider config, landing page, route handlers
src/trello-mcp-agent.ts — McpAgent DO, registers all tools
src/trello-client.ts — Typed Trello REST API client
src/auth/ — OAuth authorize + Trello callback handlers
src/tools/ — 13 tool modules, ~43 tools total

Security Rules

NEVER commit .dev.vars, API keys, or real Trello data
All tool inputs validated with Zod
Callback page uses strict CSP + X-Frame-Options: DENY
workers_dev: false in wrangler.jsonc — all traffic through custom domain

Trello

Board: https://trello.com/b/mIIu82zI/mcpfortrello

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 53 lines · 490 tokens per session scan A a5b1aa55e618

Subscribe to this mod's changes

mcpfortrello CLAUDE.md is an instructions file published in the GitHub repository michaelpryor/mcpfortrello (18 stars, last pushed 3mo ago), licensed MIT. It adds 490 tokens to every session, about $0.0020 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Project management

mcpfortrello CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
mcpfortrello CLAUDE.mdmichaelpryor/mcpfortrello	Instructions file	18	3mo ago	MIT	A	490	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

mcpfortrello: Instructions file for Claude Code