# Mcp Slack

> MCP server for slack

- **Type:** MCP server
- **Install:** `agentstack add mcp-antonio-mello-ai-mcp-slack`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [antonio-mello-ai](https://agentstack.voostack.com/s/antonio-mello-ai)
- **Installs:** 0
- **Category:** [Communication](https://agentstack.voostack.com/c/communication)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [antonio-mello-ai](https://github.com/antonio-mello-ai)
- **Source:** https://github.com/antonio-mello-ai/mcp-slack

## Install

```sh
agentstack add mcp-antonio-mello-ai-mcp-slack
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# mcp-slack

MCP server for Slack integration, built with FastMCP. Provides tools for listing channels, reading messages, and posting to Slack.

## Install

```bash
pip install -e ".[dev]"
```

## Environment Variables

| Variable | Required | Description |
|----------|----------|-------------|
| `SLACK_BOT_TOKEN` | Yes | Bot User OAuth Token (`xoxb-...`) |
| `SLACK_DEFAULT_CHANNEL` | No | Fallback channel for `slack_post_message` |

Copy `.env.example` to `.env` and fill in your values.

## Tools

| Tool | Description |
|------|-------------|
| `slack_list_channels` | List all channels accessible by the bot |
| `slack_read_channel(channel, limit?)` | Read last N messages from a channel (default: 20, max: 100) |
| `slack_post_message(channel, text)` | Send a message to a channel |

The `channel` parameter accepts either a channel name (without `#`) or a Slack channel ID.

## Slack App Setup

1. Go to [api.slack.com/apps](https://api.slack.com/apps) and create a new app
2. Under **OAuth & Permissions**, add the required **Bot Token Scopes** for the tools you want to use:

   | Tool | Required Bot Scopes |
   |------|---------------------|
   | `slack_list_channels` | `channels:read`, `groups:read` |
   | `slack_read_channel` | `channels:history`, `groups:history` |
   | `slack_post_message` | `chat:write` |
   
   *Note: Private-channel access (`groups:*`) and DM scopes are only needed if the bot operates outside public channels.*

3. Install the app to your workspace
4. Copy the **Bot User OAuth Token** (`xoxb-...`) to `SLACK_BOT_TOKEN`
5. Invite the bot to channels it should access: `/invite @your-bot-name`

### Troubleshooting: `missing_scope` Error
If a tool fails with a `missing_scope` error, it means the bot doesn't have the necessary permissions to perform that action. Check the error message to see which scope is missing, cross-reference it with the table above, and add the missing scope in your Slack App's **OAuth & Permissions** page. (Remember to reinstall the app to your workspace after changing scopes!)

## Usage

### Standalone

```bash
mcp-slack
```

### Claude Desktop config

```json
{
  "mcpServers": {
    "slack": {
      "command": "mcp-slack",
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token"
      }
    }
  }
}
```

## Development

```bash
pip install -e ".[dev]"
ruff check src/ tests/
ruff format src/ tests/
pytest
```

## License

MIT

## Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [antonio-mello-ai](https://github.com/antonio-mello-ai)
- **Source:** [antonio-mello-ai/mcp-slack](https://github.com/antonio-mello-ai/mcp-slack)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** yes
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/mcp-antonio-mello-ai-mcp-slack
- Seller: https://agentstack.voostack.com/s/antonio-mello-ai
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.