Trello MCP Server

A Model Context Protocol (MCP) server implementation for Trello, written in Kotlin. This server enables AI assistants to interact with Trello boards, lists, and cards through a standardized protocol.

Features

Board Management

• List all boards for authenticated user
• Get detailed board information
• Create new boards

List Management

• Get all lists on a board
• Create new lists with custom positioning

Card Management

• Get card details
• List all cards in a list
• Create new cards with descriptions and due dates
• Update existing cards (name, description, list, status, due date)

Prerequisites

• JDK 21 or higher
• Gradle (wrapper included)
• Trello API credentials:
  • API Key from https://trello.com/app-key
  • Token generated from the same page

Installation

1. Clone or download this repository

2. Get Trello API credentials:

   • Visit https://trello.com/app-key
   • Copy your API Key
   • Click "Token" link to generate a token with read/write permissions
   • Copy the generated token

3. Configure credentials:

   Create a .env file in the project root:

   cp .env.example .env

   Edit .env and add your credentials:

   TRELLO_API_KEY=your_api_key_here
   TRELLO_TOKEN=your_token_here
   

4. Build the project:

   ./gradlew build

Usage

Running Standalone

./gradlew run

Or using the built JAR:

java -jar build/libs/trello-mcp-server-1.0.0.jar

Configuration for Claude Desktop

Add to your Claude Desktop config file (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

Using the JAR file:

{
  "mcpServers": {
    "trello": {
      "command": "java",
      "args": [
        "-jar",
        "/absolute/path/to/trelloMCP/build/libs/trello-mcp-server-1.0.0.jar"
      ],
      "env": {
        "TRELLO_API_KEY": "your_api_key_here",
        "TRELLO_TOKEN": "your_token_here"
      }
    }
  }
}

Using Gradle:

{
  "mcpServers": {
    "trello": {
      "command": "./gradlew",
      "args": ["run", "--quiet", "--console=plain"],
      "cwd": "/absolute/path/to/trelloMCP",
      "env": {
        "TRELLO_API_KEY": "your_api_key_here",
        "TRELLO_TOKEN": "your_token_here"
      }
    }
  }
}

Using the wrapper script:

{
  "mcpServers": {
    "trello": {
      "command": "/absolute/path/to/trelloMCP/run-mcp-server.sh",
      "env": {
        "TRELLO_API_KEY": "your_api_key_here",
        "TRELLO_TOKEN": "your_token_here"
      }
    }
  }
}

Available Tools

Board Tools

list_boards

• Lists all boards for the authenticated user
• No parameters required
• Returns: Board ID, name, description, URL

get_board

• Get detailed information about a specific board
• Parameters:
  • boardId (required): The board ID

create_board

• Create a new Trello board
• Parameters:
  • name (required): Board name
  • desc (optional): Board description

List Tools

get_lists

• Get all lists on a specific board
• Parameters:
  • boardId (required): The board ID

create_list

• Create a new list on a board
• Parameters:
  • boardId (required): The board ID
  • name (required): List name
  • pos (optional): Position ('top', 'bottom', or number)

Card Tools

get_card

• Get detailed information about a card
• Parameters:
  • cardId (required): The card ID

get_cards_in_list

• Get all cards in a specific list
• Parameters:
  • listId (required): The list ID

create_card

• Create a new card in a list
• Parameters:
  • listId (required): The list ID
  • name (required): Card title
  • desc (optional): Card description
  • due (optional): Due date (ISO 8601 format)
  • pos (optional): Position ('top', 'bottom', or number)

update_card

• Update an existing card
• Parameters:
  • cardId (required): The card ID
  • name (optional): New card title
  • desc (optional): New description
  • closed (optional): Archive/unarchive (boolean)
  • idList (optional): Move to different list (list ID)
  • due (optional): New due date (ISO 8601 format)

Architecture

Components

• McpServer: Main server implementing JSON-RPC 2.0 protocol over stdio
• TrelloService: HTTP client for Trello REST API using Ktor
• Models:
  • MCP protocol models (JSON-RPC, tools, responses)
  • Trello entity models (boards, lists, cards, labels, members)

Protocol

Implements MCP specification version 2024-11-05:

• JSON-RPC 2.0 over standard input/output
• Capability negotiation during initialization
• Tool discovery and execution
• Structured error handling

Development

Project Structure

src/main/kotlin/com/example/mcp/trello/
├── McpServer.kt           # Main MCP server implementation
├── TrelloServer.kt        # Entry point
├── TrelloService.kt       # Trello API client
└── models/
    ├── McpModels.kt       # MCP protocol models
    └── TrelloModels.kt    # Trello entity models

Building

# Build JAR
./gradlew build

# Clean build
./gradlew clean build

# Run tests
./gradlew test

Dependencies

• Kotlin 2.1.0
• Ktor Client 2.3.7 (HTTP client)
• kotlinx.serialization 1.6.2 (JSON handling)
• kotlin-logging 5.1.0 (Logging)
• dotenv-kotlin 6.4.1 (Environment configuration)

Troubleshooting

Server won't start

1. Check that Java 21+ is installed: java -version
2. Verify Trello credentials are set in .env or environment variables
3. Check the error log at /tmp/trello-mcp-stderr.log (when using wrapper script)

API Errors

• Verify your API key and token are valid
• Check token has necessary permissions (read/write)
• Ensure board/list/card IDs are correct

Build Issues

If you encounter Java version issues:

# Stop Gradle daemon
./gradlew --stop

# Build with specific Java version
JAVA_HOME=/path/to/java21 ./gradlew build

License

This project is provided as-is for use with the Model Context Protocol.

Links

• Trello API Documentation
• Model Context Protocol
• Get Trello API Key