Skip to main content
Glama
Sign In
Slack Message Sender

Slack Message Sender

by a-g-e-n-t-s
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Remote

MCP_Slack_Server

MCP Server that provides Slack message sending capabilities for Claude Desktop and KADI agents.

Overview

This server is part of the KADI Slack bot architecture. It:

  1. Provides stateless message sending tools

  2. Resolves channel names to IDs automatically

  3. Supports both direct messages and thread replies

  4. Works with Claude Desktop and Agent_TypeScript via KADI broker

Related MCP server: Slack MCP Server

Architecture

Claude Desktop / Agent_TypeScript
              ↓
      KADI Broker (MCP Upstream)
              ↓
    MCP_Slack_Server (this project)
              ↓
      Slack Web API
              ↓
         Slack Channel

Installation

cd C:\p4\Personal\SD\MCP_Slack_Server
npm install

Configuration

Create .env file:

SLACK_BOT_TOKEN=xoxb-your-bot-token
MCP_LOG_LEVEL=info

Required Slack Scopes

  • chat:write - Send messages to channels

  • chat:write.public - Send messages to public channels without joining

  • channels:read - List and resolve channel names

  • groups:read - Access private channels (if needed)

Usage

Development Mode

npm run dev

Production Mode

npm run build
npm start

As MCP Upstream (via KADI Broker)

Add to kadi-broker/mcp-upstreams.json:

{
  "id": "slack-server",
  "name": "Slack Message Sender",
  "type": "stdio",
  "prefix": "slack",
  "networks": ["global", "slack"],
  "stdio": {
    "command": "node",
    "args": ["C:/p4/Personal/SD/MCP_Slack_Server/dist/index.js"],
    "env": {
      "SLACK_BOT_TOKEN": "xoxb-..."
    }
  }
}

Tools

send_message

Send a message to a Slack channel.

Input:

{
  "channel": "#general",  // or "C09T6RU41HP"
  "text": "Hello from Claude!",
  "thread_ts": "1234567890.123456"  // optional
}

Output:

{
  "success": true,
  "message": "Message sent successfully",
  "timestamp": "1234567890.123456",
  "channel": "C09T6RU41HP"
}

send_reply

Reply to a message in a thread.

Input:

{
  "channel": "C09T6RU41HP",
  "thread_ts": "1234567890.123456",
  "text": "This is a threaded reply"
}

Output:

{
  "success": true,
  "message": "Reply sent successfully",
  "timestamp": "1234567890.654321",
  "channel": "C09T6RU41HP",
  "thread_ts": "1234567890.123456"
}

Integration Examples

From Claude Desktop

Send a message to #general saying "Hello team!"

From Agent_TypeScript

await client.getBrokerProtocol().invokeTool({
  targetAgent: 'slack-server',
  toolName: 'slack_send_message',
  toolInput: {
    channel: '#general',
    text: 'Hello from Agent_TypeScript!'
  },
  timeout: 10000
});

Reply to Slack Mention

// After getting mention from MCP_Slack_Client
const mention = mentions[0];

await client.getBrokerProtocol().invokeTool({
  targetAgent: 'slack-server',
  toolName: 'slack_send_reply',
  toolInput: {
    channel: mention.channel,
    thread_ts: mention.thread_ts,
    text: claudeResponse
  },
  timeout: 10000
});

License

MIT

Available Tools

2 tools
send_messageB

Send a message to a Slack channel. Can be used by Claude Desktop and KADI agents to send messages to channels or start new threads.

Inputs: channel (required), text (required), thread_ts.

send_replyA

Reply to a message in a Slack thread. Useful for maintaining conversation context.

Inputs: channel (required), thread_ts (required), text (required).

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections.

Loading tool schema changelog…

    Deploy Server
    One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

    TDQS

    A3.6/5.0

    Scored across 2 tools

    Disambiguation5/5

    The two tools have clearly distinct purposes: one sends a new message or starts a thread, the other replies within a thread. No ambiguity.

    Naming Consistency5/5

    Both tools follow a consistent 'send_' prefix and verb_noun pattern ('send_message', 'send_reply'), making the naming predictable.

    Tool Count3/5

    With only 2 tools, the server is very focused. While this is appropriate for a minimal message sender, it feels slightly thin for general Slack interaction.

    Completeness3/5

    The tool set covers sending and replying, but lacks other common Slack operations (e.g., reading, editing, deleting messages), leaving notable gaps.

    Maintenance

    ActivityInactive
    ResponsivenessNo recent community issues

    Resources

    Related MCP Connectors

    Related MCP Servers