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Slack MCP Server

Provides a Slack-based MCP server that controls Slack actions via a Python client and C# server integration.

Installation

Add the following to your MCP client configuration file.

Configuration

{
  "mcpServers": {
    "antonhofstader-slack-mcp": {
      "command": "dotnet",
      "args": [
        "run",
        "--project",
        "../server-csharp/SlackMcpServer.csproj"
      ],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token-here"
      }
    }
  }
}

You deploy a four-layer MCP implementation that connects a Python client to a C# Slack-integrated server. This setup enables natural language prompts to drive Slack actions such as posting messages, reading history, managing channels, and reacting to messages, all through a unified MCP protocol.

How to use

You interact with the Slack MCP server through the Python client. Start by launching the C# Slack MCP server in stdio mode, then run the Python client to communicate via JSON-RPC over standard input and output. The agent interprets your prompts, decides which Slack tool to call, and returns human-friendly responses. You can perform tasks like listing channels, creating channels, sending messages, reading history, and adding reactions by stating your intent in natural language.

How to install

Prerequisites you need before starting:

Python 3.11+
.NET SDK 8.0+
Slack Bot Token (xoxb-…)

Additional setup steps

1) Set your Slack bot token in your environment.

2) Build the C# server and prepare the Python client to connect to it.

Troubleshooting

If you encounter issues, verify that environment variables are set, the C# server builds successfully, and the Python client launches with the correct server command.

Available tools

send_message

Post a message to a Slack channel or thread.

get_history

Read recent messages from a channel or thread.

list_channels

List channels in the Slack workspace.

create_channel

Create a new public channel.

add_reaction

Add an emoji reaction to a message.

list_users

Enumerate workspace members.