Slack Lists MCP Server

Slack Lists MCP Server

A Model Context Protocol (MCP) server that gives AI assistants full read and write access to Slack Lists.

This server acts as a bridge between AI models and Slack, enabling seamless creation, retrieval, updating, deletion, filtering, and management of Slack List items through a standardized protocol. It empowers AI assistants like Claude Desktop to become powerful productivity tools for managing tasks, projects, and data within Slack.

This project provides a complete package with:

• Comprehensive Toolset: Create, query, update, delete, filter, and export list items.
• Robust Implementation: Built with Python, FastMCP, and best practices.
• Easy Deployment: Simple setup with environment variables.
• Detailed Documentation: Full README, tool reference, and examples.
• Extensible Design: Easily add new tools and functionality.

The write paths have been verified against a live Slack workspace (see Verification status).

Features

This MCP server provides a rich set of tools for interacting with Slack Lists:

• Create Single Item: Add one item to a list with detailed fields.
• Bulk Create Items: Add multiple items at once with built-in rate limiting to respect Slack's API.
• Retrieve Items: Fetch a list of items with optional metadata.
• Update Items: Update any cell on an existing item — check a task off, reassign it, reschedule it, or edit any field (full task management).
• Delete Items: Permanently remove an item from a list.
• Discover Columns: Infer a list's column IDs, types, and select option IDs from its existing items (Slack exposes no schema API, so this saves you from hunting for IDs in browser dev tools).
• Filter Items: Powerful server-side filtering based on any field value (status, assignee, priority, etc.).
• Export Data: Export list items to JSON or CSV format for analysis or backup.
• Subtask Creation: Create sub-items under a parent item.
• Full Field Support: Works with all Slack List field types (text, date, user, select, checkbox, number, email, phone).
• Error Handling: Robust error handling and clear feedback for failed operations.

Getting Started

Follow these steps to get your Slack Lists MCP server up and running.

Prerequisites

• Python 3.10+
• Slack Workspace: A Slack workspace where you have permission to install apps.
• Slack Bot Token: A bot token with lists:read and lists:write scopes.

1. Create a Slack App

1. Go to the Slack API website and click Create New App.
2. Choose "From scratch", give your app a name (e.g., "Lists MCP Server"), and select your workspace.
3. In the app settings, go to OAuth & Permissions.
4. Under Bot Token Scopes, add the following scopes:
   • lists:read
   • lists:write
5. Click Install to Workspace at the top of the page and authorize the app.
6. Copy the Bot User OAuth Token (it starts with xoxb-). This is your SLACK_BOT_TOKEN.

2. Installation

Clone the repository and install the dependencies:

# Clone the repository
git clone https://github.com/justadityaraj/slack-lists-mcp.git
cd slack-lists-mcp

# Create and activate a virtual environment
python3 -m venv .venv
source .venv/bin/activate

# Install dependencies
pip install -r requirements.txt

3. Configuration

Create a .env file by copying the example:

cp .env.example .env

Open the .env file and set your SLACK_BOT_TOKEN:

SLACK_BOT_TOKEN=xoxb-your-bot-token-here

The server loads this .env (from the project root) automatically on startup, so you do not need to put the token anywhere else. A real SLACK_BOT_TOKEN environment variable always takes precedence over the file.

4. Running the Server

You can run the server directly from the command line:

python src/slack_lists_server.py

The server will start and listen for MCP requests over STDIO.

5. Connecting to an MCP Host (e.g., Claude Desktop)

To use the server with an AI assistant, you need to configure your MCP host.

1. Open your MCP host's configuration file (e.g., mcp_servers.json for Claude Desktop).
2. Add a new server entry pointing to your slack_lists_server.py script.

Example mcp_servers.json configuration:

{
  "mcpServers": {
    "slack-lists": {
      "command": "/path/to/your/.venv/bin/python",
      "args": ["/path/to/slack-lists-mcp-server/src/slack_lists_server.py"],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-bot-token-here"
      }
    }
  }
}

Important: Make sure to use the absolute path to your Python executable and the server script. Because the server reads the token from the project .env, the env block above is optional.

Once configured, restart your MCP host. The Slack Lists tools should now be available to your AI assistant.

Claude Code (CLI)

claude mcp add slack-lists -s user -- /abs/path/.venv/bin/python /abs/path/slack-lists-mcp/src/slack_lists_server.py

No -e SLACK_BOT_TOKEN=... is needed; the server picks the token up from .env.

Tool Reference

This server exposes the following tools to your AI assistant. Each tool is designed to be intuitive and powerful, with clear descriptions and parameters.

---

create_list_item

Creates a single new item in a Slack List.

Description: This tool creates one item in the specified Slack List. The item must have at least a title field, and can include additional fields as needed. All field values are validated against the list's schema.

Parameters:

• list_id (string, required): The ID of the Slack List (e.g., F1234ABCD).
• title (string, required): The main title/text for the item.
• title_column_id (string, optional): Column ID for the title field (defaults to Col10000000).
• additional_fields (string, optional): JSON string of additional fields. See Field Formats for details.
• parent_item_id (string, optional): Optional parent item ID to create a subtask.

Example Prompt:

"Create a new task in my project list F1234ABCD with the title 'Finish Q4 report' and a due date of 2024-12-20."

---

create_multiple_list_items

Creates multiple items in a Slack List with rate limiting.

Description: This tool allows bulk creation of list items. Each item is created individually with proper rate limiting to respect Slack's API limits (~50 requests per minute).

Parameters:

• list_id (string, required): The ID of the Slack List.
• items_data (string, required): JSON array of items to create. See Bulk Creation Format for details.
• title_column_id (string, optional): Column ID for the title field.
• rate_limit_delay (float, optional): Delay between requests in seconds (default: 1.2s).

Example Prompt:

"Add these three tasks to my list F1234ABCD: 1. Design mockups (due 12/10), 2. Write tests (due 12/15), 3. Update documentation (due 12/20)."

---

get_list_items

Retrieves items from a Slack List.

Description: This tool fetches items from the specified Slack List with optional metadata. Use this to view current list contents, check item details, or prepare data for filtering.

Parameters:

• list_id (string, required): The ID of the Slack List.
• limit (integer, optional): Maximum number of items to retrieve (default: 50, max: 100).
• include_metadata (boolean, optional): Whether to include creation/update metadata (default: True).

Example Prompt:

"Show me the 10 most recent items in my 'Tasks' list F5678EFGH."

---

filter_list_items

Filters and retrieves items from a Slack List based on field values.

Description: This tool allows you to search and filter list items by specific field values. Useful for finding items with a specific status, assignee, priority, or any other field.

Parameters:

• list_id (string, required): The ID of the Slack List.
• filter_column_id (string, required): Column ID to filter by.
• filter_value (string, required): Value to search for.
• filter_operator (string, optional): How to match the value. See Filter Operators for options.
• max_items (integer, optional): Maximum number of items to process (default: 100).

Example Prompt:

"Find all tasks in list F1234ABCD assigned to me that are marked as 'High' priority."

---

export_list_items

Exports items from a Slack List to a structured data format.

Description: This tool exports list items to JSON or CSV format, with optional filtering. Useful for backup, analysis, or integration with other systems.

Parameters:

• list_id (string, required): The ID of the Slack List.
• export_format (string, optional): Output format - json or csv (default: json).
• filter_column_id (string, optional): Optional column ID to filter by.
• filter_value (string, optional): Value to filter for (required if filter_column_id is provided).
• filter_operator (string, optional): Filter operator.

Example Prompt:

"Export all completed tasks from my project list F1234ABCD to a CSV file."

---

update_list_item

Updates one or more cells on an existing Slack List item (row). This is the tool for full task management: check a task off, reassign it, reschedule it, or edit any field — in a single call.

Description: Updates the given columns on the item identified by row_id. Find the row_id with get_list_items or filter_list_items (it is each item's id, e.g. Rec1234567). Find column_ids and select option IDs with discover_list_columns.

Parameters:

• list_id (string, required): The ID of the Slack List (e.g., F1234ABCD).
• row_id (string, required): The ID of the item/row to update (e.g., Rec1234567).
• fields (string, required): JSON array of cells to update. Each cell is {"column_id": "...", "type": "...", "value": ...}. See Field Formats. Supported types: text, date, user, select, checkbox, number, email, phone.

Example Prompt:

"Mark task Rec1234567 in list F1234ABCD as done, reassign it to U1234567, and move the due date to 2025-09-20."

---

delete_list_item

Permanently deletes an item (row) from a Slack List. This cannot be undone.

Parameters:

• list_id (string, required): The ID of the Slack List (e.g., F1234ABCD).
• row_id (string, required): The ID of the item/row to delete (e.g., Rec1234567).

Example Prompt:

"Delete item Rec1234567 from list F1234ABCD."

---

discover_list_columns

Discovers a list's columns by inspecting its existing items. Slack exposes no API to read a list's schema directly, so this infers each column's ID, type, a sample value, and (for select columns) the option IDs from the data already in the list. Use it to find the column_id and select option IDs needed by create_list_item and update_list_item.

Note: A column is only discoverable if at least one item has a value in it. Empty columns will not appear.

Parameters:

• list_id (string, required): The ID of the Slack List (e.g., F1234ABCD).
• sample_size (integer, optional): How many items to scan, 1-1000 (default: 100).

Example Prompt:

"What columns does list F1234ABCD have, and what are the status option IDs?"

Data Formats

Field Formats

When using create_list_item or create_multiple_list_items, you need to provide field data in a specific JSON format. The additional_fields and items_data parameters expect a JSON string.

Each field is an object with column_id, type, and value:

[
  {
    "column_id": "Col10000001",
    "type": "date",
    "value": "2024-12-31"
  },
  {
    "column_id": "Col10000002",
    "type": "select",
    "value": ["OptionID123"]
  },
  {
    "column_id": "Col10000003",
    "type": "user",
    "value": ["U1234567", "U2345678"]
  },
  {
    "column_id": "Col10000004",
    "type": "checkbox",
    "value": true
  }
]

Supported Field Types:

• text: String value.
• date: String in YYYY-MM-DD format.
• user: Array of Slack user IDs (e.g., ["U1234567"]).
• select: Array of select option IDs.
• checkbox: Boolean true or false.
• number: Numeric value.
• email: String email address.
• phone: String phone number.

Bulk Creation Format

The items_data parameter for create_multiple_list_items expects a JSON array where each object represents an item to be created.

[
  {
    "title": "First Task",
    "fields": [
      {"column_id": "Col123", "type": "date", "value": "2024-12-15"}
    ]
  },
  {
    "title": "Second Task",
    "fields": [
      {"column_id": "Col123", "type": "date", "value": "2024-12-20"},
      {"column_id": "Col456", "type": "user", "value": ["U1234567"]}
    ]
  }
]

Filter Operators

The filter_list_items tool supports the following operators:

• contains: Field contains the value (case-insensitive).
• equals: Field exactly matches the value (case-insensitive).
• not_equals: Field does not match the value.
• not_contains: Field does not contain the value.
• exists: Field has any non-empty value.
• not_exists: Field is empty or missing.

Troubleshooting

• invalid_auth Error: Your SLACK_BOT_TOKEN is likely incorrect or has been revoked. Generate a new one and update your .env file.
• missing_scope Error: Ensure your Slack app has both lists:read and lists:write scopes.
• list_not_found Error: The list_id you provided is incorrect. Double-check the ID in Slack.
• Server Not Responding: Make sure the server is running and that the path in your MCP host configuration is correct. Check for any errors in the server logs.
• JSON Errors: Validate your JSON strings for additional_fields and items_data using an online validator.

How to Find List and Column IDs

1. List ID: Open the list in Slack. The ID is the last part of the URL (e.g., https://app.slack.com/client/.../F1234ABCD).
2. Column ID: The easiest way is the discover_list_columns tool, which lists every column's ID, type, and select option IDs by inspecting the list's existing items. (You can also inspect browser network requests, or read the raw output of get_list_items.)

Contributing

Contributions are welcome! If you have ideas for new features, bug fixes, or improvements, please open an issue or submit a pull request. See CONTRIBUTING.md for more details.

Verification status

All tools are covered by unit tests and have been exercised against a live Slack workspace: discover_list_columns, create_list_item, update_list_item (text, user, date, and checkbox cells, including a single multi-cell "check off + reassign + reschedule" update), and delete_list_item all round-trip correctly.

One field shape differs from the published docs: checkbox cells take a bare boolean ("checkbox": true), not an array. The docs show "checkbox": [boolean], but the live API rejects the array form with invalid_arguments and returns the value as a bare bool, so this server sends a bare bool.

Credits

This project is derived from maplehilllabs/mcp-slack-lists (MIT), extended with update_list_item, delete_list_item, and discover_list_columns plus full field-type support.

License

This project is licensed under the MIT License. See the LICENSE file for details.