Slack Agent CLI

A CLI and Model Context Protocol (MCP) server for Slack API integration. Use slack from the terminal for scripting and agent workflows, or slack mcp for AI assistant integration via stdio MCP.

AI agents: See AGENTS.md for install, auth, all commands, MCP tool names, and workflow examples.

Features

Channel Management

• List all accessible channels (public/private)
• Get channel information and details
• Create new channels
• Archive channels
• Join/leave channels
• Set channel topics
• Fetch channel message history

Messaging

• Post messages to channels
• Reply to message threads
• Update and delete messages
• Add and remove emoji reactions
• Get message reactions

Direct Messages (DMs)

• Send direct messages to users
• List DM and group DM conversations
• Fetch DM conversation history
• Open new DM conversations

Search (requires User Token)

• Search messages across the workspace
• Search files
• Combined search for messages and files

User Management

• List workspace users
• Get user profile information
• Check user presence/online status
• Look up users by email
• Get bot and team information

Prerequisites

• Python 3.10 or higher
• A Slack workspace with admin access to create apps
• Slack Bot Token (xoxb-...) for most operations
• Slack User Token (xoxp-...) for search functionality

Installation

npm (recommended)

Requires Node.js 18+ and Python 3.10+.

npm install -g slack-agent-cli
slack --version

MCP via global install:

slack mcp

From source (Python)

1. Clone the Repository

git clone https://github.com/bcharleson/slack-agent-cli.git
cd slack-agent-cli

2. Create Virtual Environment

python3.12 -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

3. Install Dependencies

pip install -e .

Or install from requirements:

pip install -r requirements.txt

Slack App Setup

1. Create a Slack App

1. Go to Slack API Apps
2. Click "Create New App" → "From scratch"
3. Name your app and select your workspace

2. Configure Bot Token Scopes

Navigate to OAuth & Permissions and add these Bot Token Scopes:

Channels

• channels:read - View basic channel info
• channels:write - Manage public channels
• channels:history - View messages in public channels
• groups:read - View private channels
• groups:write - Manage private channels
• groups:history - View messages in private channels

Messaging

• chat:write - Send messages
• reactions:read - View reactions
• reactions:write - Add reactions

Direct Messages

• im:read - View DM info
• im:write - Start DMs
• im:history - View DM history
• mpim:read - View group DM info
• mpim:write - Start group DMs
• mpim:history - View group DM history

Users

• users:read - View users
• users:read.email - View user emails

3. Configure User Token Scopes (for Search)

If you need search functionality, add these User Token Scopes:

• search:read - Search messages and files

4. Install the App

1. Click "Install to Workspace"
2. Authorize the app
3. Copy the Bot User OAuth Token (starts with xoxb-)
4. If using search, also copy the User OAuth Token (starts with xoxp-)

Configuration

Environment Variables

Create a .env file in the project root:

# Required: Bot Token for most operations
SLACK_BOT_TOKEN=xoxb-your-bot-token-here

# Optional: User Token for search functionality
SLACK_USER_TOKEN=xoxp-your-user-token-here

You can copy the example file:

cp .env.example .env
# Then edit .env with your tokens

Usage

CLI

After installation, the slack command exposes grouped subcommands that mirror the MCP tools:

# Channels
slack channels list
slack channels info C01234567
slack channels history C01234567 --limit 10

# Messages
slack messages post C01234567 "Hello from the CLI"
slack messages reply C01234567 1710000000.000100 "Thread reply"

# DMs
slack dms send U01234567 "Quick note from CLI"
slack dms list

# Search (requires SLACK_USER_TOKEN)
slack search messages "project update in:#general"

# Users / workspace
slack users list
slack users lookup [email protected]
slack workspace team

# Output formatting
slack --pretty channels list
slack --output json --quiet channels list

Global options:

• --bot-token / SLACK_BOT_TOKEN
• --user-token / SLACK_USER_TOKEN
• --output json|pretty (default: json)
• --pretty shorthand
• --quiet for exit-code-only automation

MCP server

Start the stdio MCP server:

slack mcp
# or
slack-agent-cli mcp

Running the Server (development)

source venv/bin/activate
python -m slack_agent_cli.cli mcp

Claude Desktop Configuration

Add to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "slack": {
      "command": "/path/to/slack-agent-cli/venv/bin/python",
      "args": ["-m", "slack_agent_cli"],
      "cwd": "/path/to/slack-agent-cli",
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-bot-token",
        "SLACK_USER_TOKEN": "xoxp-your-user-token"
      }
    }
  }
}

Replace /path/to/slack-agent-cli with the actual path to your installation.

Cursor IDE Configuration

Add to your Cursor MCP settings (~/.cursor/mcp.json):

{
  "mcpServers": {
    "slack-agent-cli": {
      "command": "slack",
      "args": ["mcp"],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-bot-token",
        "SLACK_USER_TOKEN": "xoxp-your-user-token"
      }
    }
  }
}

Or with a global install:

{
  "mcpServers": {
    "slack-agent-cli": {
      "command": "slack",
      "args": ["mcp"],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-bot-token",
        "SLACK_USER_TOKEN": "xoxp-your-user-token"
      }
    }
  }
}

Available Tools

Channel Tools

| Tool | Description | |------|-------------| | list_channels | List all accessible channels | | get_channel_info | Get details about a specific channel | | create_channel | Create a new channel | | archive_channel | Archive a channel | | get_channel_history | Fetch message history | | join_channel | Join a channel | | leave_channel | Leave a channel | | set_channel_topic | Set channel topic |

Message Tools

| Tool | Description | |------|-------------| | post_message | Post a message to a channel | | reply_to_thread | Reply in a thread | | get_thread_replies | Get all replies in a thread | | add_reaction | Add emoji reaction | | remove_reaction | Remove emoji reaction | | get_message_reactions | Get reactions on a message | | update_message | Update an existing message | | delete_message | Delete a message |

DM Tools

| Tool | Description | |------|-------------| | send_dm | Send a direct message | | list_conversations | List DM conversations | | get_dm_history | Fetch DM history | | open_dm | Open a DM conversation |

Search Tools (requires User Token)

| Tool | Description | |------|-------------| | search_messages | Search messages | | search_files | Search files | | search_all | Search both messages and files |

User Tools

| Tool | Description | |------|-------------| | list_users | List workspace users | | get_user_info | Get user details | | get_user_presence | Check if user is online | | lookup_user_by_email | Find user by email | | get_user_profile | Get detailed profile | | get_bot_info | Get bot identity | | get_team_info | Get workspace info |

Testing

Using MCP Inspector

npx @modelcontextprotocol/inspector python -m slack_agent_cli

This opens a web interface to test all available tools interactively.

Manual Testing

1. Start the server
2. Use Claude Desktop or another MCP client
3. Try basic commands:
   • "List all channels in the workspace"
   • "Get the history of #general channel"
   • "Send a message to #test-channel saying Hello!"

Troubleshooting

"SLACK_BOT_TOKEN is not set"

Ensure your .env file exists and contains the token, or set it in your MCP client configuration.

"Search requires a User Token"

Search operations require a User Token (SLACK_USER_TOKEN). Add User Token scopes to your Slack app and include the token.

"channel_not_found"

The bot may not have access to the channel. Ensure:

1. The channel exists
2. The bot is a member of private channels
3. The channel ID is correct (use list_channels to find IDs)

"missing_scope"

Your Slack app is missing required permissions. Check the OAuth scopes section above and add the missing scopes in your Slack app settings.

Development

Project Structure

slack-agent-cli/
├── src/
│   └── slack_agent_cli/
│       ├── cli/
│       │   └── main.py            # Click CLI + `slack mcp`
│       ├── core/
│       │   └── output.py          # JSON/pretty output helpers
│       ├── operations/            # Shared handlers for CLI + MCP
│       │   ├── channels.py
│       │   ├── messages.py
│       │   ├── search.py
│       │   └── users.py
│       ├── tools/                   # MCP tool registration
│       ├── utils/
│       │   └── slack_client.py
│       └── server.py              # FastMCP stdio server
├── pyproject.toml
├── package.json
├── AGENTS.md                      # AI agent guide (commands, MCP, workflows)
├── requirements.txt
├── .env.example
└── README.md

Adding New Tools

1. Create or edit a file in src/slack_agent_cli/tools/
2. Define tools using the @mcp.tool() decorator
3. Register the tools in the server by calling the registration function

License

MIT License

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.