Trello MCP Server

🔀 Active fork. This is a maintained fork of kocakli/Trello-Desktop-MCP integrating contributions from across the fork ecosystem (kevinhillinger, zonca, dbz-max, maks244, jantman, ThatIanMcShane, josh-argyle). PRs welcome — see Credits for what each contributor brought in. Published on npm as atlassian-trello-mcp.

A Model Context Protocol (MCP) server for Trello that works with any MCP-compatible client -- Claude Desktop, Claude Code, Gemini CLI, and more.

Provides 46 tools covering boards, cards, lists, labels, checklists, attachments, members, custom fields, and search.

Quick Start

1. Get Trello API credentials

• Visit https://trello.com/app-key
• Copy your API Key
• Click "Generate a Token" for read/write access

2. Install

The easiest path is npx — no clone, no build, just run:

npx atlassian-trello-mcp

Or install from source:

git clone https://github.com/agrath/Trello-Desktop-MCP.git
cd Trello-Desktop-MCP
npm install
npm run build

3. Configure your MCP client

{
  "mcpServers": {
    "trello": {
      "command": "npx",
      "args": ["-y", "atlassian-trello-mcp"],
      "env": {
        "TRELLO_API_KEY": "your-api-key",
        "TRELLO_TOKEN": "your-token"
      }
    }
  }
}

claude mcp add trello -- npx -y atlassian-trello-mcp

{
  "mcpServers": {
    "trello": {
      "command": "npx",
      "args": ["-y", "atlassian-trello-mcp"],
      "env": {
        "TRELLO_API_KEY": "your-api-key",
        "TRELLO_TOKEN": "your-token"
      }
    }
  }
}

TRELLO_API_KEY=your-key TRELLO_TOKEN=your-token npx atlassian-trello-mcp
# or, from a source clone:
TRELLO_API_KEY=your-key TRELLO_TOKEN=your-token node dist/index.js

Credentials

Credentials can be provided two ways:

1. Environment variables (recommended): Set TRELLO_API_KEY and TRELLO_TOKEN
2. Per-request: Pass apiKey and token as tool parameters (overrides env vars)

Available Tools (46)

Boards & Lists

Cards

Comments & Activity

Labels

Members on Cards

Attachments

Checklists

Check Items

Search

Configuration

Read-only mode

Set TRELLO_READ_ONLY=true to disable all write operations. Only read/query tools will be available.

{
  "env": {
    "TRELLO_API_KEY": "your-key",
    "TRELLO_TOKEN": "your-token",
    "TRELLO_READ_ONLY": "true"
  }
}

Compact mode

Several tools support a compact parameter (default: true) that returns minimal fields to reduce response size. Set compact: false for full details including descriptions, labels, members, and custom fields.

Tools with compact mode: get_board_details, trello_get_board_cards, trello_get_list_cards, trello_search.

Image attachment download

When get_card is called and the card has image attachments, the server downloads them and returns them as inline MCP image content blocks alongside the JSON — letting the client see card images directly. Downloads are restricted to Trello-hosted URLs (*.trello.com, trello-attachments.s3.amazonaws.com) and capped at 5 MB per image to mitigate SSRF and payload-bloat risks.

Set TRELLO_DOWNLOAD_IMAGES=false (or 0/no/off) to disable entirely — the server will skip the extra getCardAttachments call and return text only. Default is enabled.

Logging

Set TRELLO_MCP_LOGGING=true to enable file-based logging via Pino. Logs are written to dist/logs/app.log.

Development

Project structure

src/
  index.ts              Entry point (credential injection, tool routing)
  server.ts             MCP server factory (read-only mode support)
  tools/
    boards.ts           Board tools (list, details, lists, filter)
    cards.ts            Card tools (CRUD, archive)
    lists.ts            List tools (cards, create list, comments)
    members.ts          Member tools (user boards, member details)
    search.ts           Search tool
    advanced.ts         Labels, attachments, members on cards, custom fields
    checklists.ts       Checklist and check item tools (13 tools)
  trello/
    client.ts           TrelloClient (API calls, retry, rate limiting)
  types/
    trello.ts           TypeScript interfaces
  utils/
    validation.ts       Zod schemas, extractCredentials, extractTrelloId
    logger.ts           Pino file logger
    health.ts           Health check utility
    appInsights.ts      Telemetry (no-op)
tests/
  validation.test.ts    Validation and credential extraction tests
  trelloClient.test.ts  API client tests (mocked fetch)
  tools.test.ts         Tool handler tests (mocked client)

Build & test

npm install
npm run build
npm test
npm run type-check

Key patterns

• ID resolution: All tools accept Trello URLs, short IDs, or full 24-char hex IDs via extractTrelloId()
• Credential fallback: extractCredentials() checks args first, then env vars
• Retry with backoff: TrelloClient retries on 500/network errors (3 attempts, exponential backoff)
• Rate limiting: Extracts and returns x-rate-limit-* headers from every response
• Validation: Zod schemas validate all inputs before API calls

Contributing

Pull requests are welcome and actively reviewed. This fork is maintained by an extensive Trello user, so features get real-world testing.

If you've forked the original project and built something useful, please submit a PR here rather than maintaining a separate fork -- it's easier for everyone to benefit from a single well-maintained project.

To contribute:

1. Fork this repo
2. Create a feature branch
3. Add tests for new functionality
4. Run npm test and npm run build
5. Submit a pull request with a clear description of what and why

Credits

This project is a fork of kocakli/Trello-Desktop-MCP. Features and ideas were incorporated from across the fork ecosystem:

• kocakli -- Original project, MCP client-agnostic rebranding, stderr logging fix
• kevinhillinger -- Credential injection architecture, label deletion, card member management, card archiving, expanded TypeScript types, resources layer
• zonca -- Centralized credential handling with env var fallback, label management tools, comprehensive unit tests, improved TypeScript types replacing any
• dbz-max -- Custom fields support (board custom fields + card custom field items)
• maks244 -- Read-only mode concept, list filtering by name, credential stripping from telemetry logs
• jantman -- Fix for numeric pos values rejected when sent as strings by MCP clients
• ThatIanMcShane -- Bumped @modelcontextprotocol/sdk 1.0.4 → 1.29.0 to fix connection timeouts with current Claude Code releases
• josh-argyle -- Auto-download image attachments in get_card responses as inline MCP image content blocks (with allowlist + size cap added during port)

License

MIT