Slack

A Model Context Protocol (MCP) server that enables LLMs to interact with Slack workspaces through OAuth 2.0 authentication.

- 🔐OAuth 2.0 Authentication: Secure Slack OAuth flow with automatic token management
- 🚀FastMCP Framework: Built with the official MCP SDK's FastMCP framework
- 💾Token Persistence: Tokens are saved locally or in DynamoDB for cloud deployments
- 📱Slack Integration: Post messages and list channels in Slack workspaces
- 🔄Dynamic Client Registration: Supports VSCode MCP extension and other clients
- ☁️GitHub + App Runner: Deploy directly from GitHub with AWS App Runner

- Python 3.11+
- Slack App with OAuth 2.0 configured
- uv (Python package manager)
- Create a new Slack App athttps://api.slack.com/apps
- Add OAuth Scopes in "OAuth & Permissions":

# Clone the repository git clone https://github.com/miyatsuki/study-slack-remote-mcp.git cd study-slack-remote-mcp # Install dependencies using uv uv sync

# Required: Slack OAuth credentials SLACK_CLIENT_ID=your_client_id SLACK_CLIENT_SECRET=your_client_secret # Optional: Service base URL (for production deployments) # SERVICE_BASE_URL=https://your-apprunner-url.awsapprunner.com

# Start the server uv run python server.py # Or run in background nohup uv run python server.py > server.log 2>&1 &

{ "mcpServers": { "slack": { "command": "uv", "args": [ "--directory", "/path/to/slack-mcp-server", "run", "python", "server.py" ] } } }

-

list_channels: Get a list of Slack channels

Returns: Dictionary mapping channel names to IDs

post_message: Post a message to a Slack channel

Args: - channel_id: Channel ID (required) - text: Message text (required) Returns: Success/failure message

get_auth_status: Check authentication status

Returns: Current authentication state and session info

- When a tool is first used, the OAuth flow automatically starts
- A browser window opens for Slack authorization
- After authorization, the token is saved for future use
- Subsequent requests use the cached token

The server uses FastMCP's built-in OAuth 2.0 support with dynamic client registration. This allows compatibility with various MCP clients including VSCode's MCP extension.

- OAuth tokens are mapped between MCP tokens and Slack tokens internally
- Tokens are persisted locally in memory (or DynamoDB in cloud)
- OAuth flow starts automatically when tools are first used
- Dynamic client registration supported for VSCode and other clients

- 8080: MCP server endpoint (includes health check and OAuth callback routes)

The project uses ECR-based deployment with AWS App Runner for production:

# First, set up AWS Systems Manager parameters: aws ssm put-parameter --name "/slack-mcp/dev/client-id" --value "your-client-id" --type "String" aws ssm put-parameter --name "/slack-mcp/dev/client-secret" --value "your-secret" --type "SecureString" aws ssm put-parameter --name "/slack-mcp/dev/service-base-url" --value "https://your-apprunner-url.awsapprunner.com" --type "String" # Build and push Docker image to ECR: ./build-and-push.sh # Create App Runner service (if not exists) or update existing service aws apprunner update-service --service-arn <your-service-arn> --source-configuration '...'

- Deployment from ECR with pre-built Docker images
- Built-in HTTPS with automatic certificates
- Manual deployment control (auto-deploy disabled by default)
- Auto-scaling and simplified management
- Avoids Python 3.11 build issues with App Runner's source code deployment

study-slack-remote-mcp/ ├── server.py # Main MCP server using FastMCP framework ├── slack_oauth_provider.py # Slack OAuth provider implementation ├── storage_interface.py # Storage abstraction (local/cloud) ├── storage_dynamodb.py # DynamoDB storage for AWS ├── token_storage.py # Local file-based token storage ├── Dockerfile # Docker container configuration ├── build-and-push.sh # ECR deployment script ├── requirements.txt # Python dependencies for Docker ├── pyproject.toml # Project dependencies ├── uv.lock # Locked dependencies ├── tests/ # Unit tests ├── infrastructure/ # AWS CDK deployment code ├── CLAUDE.md # Development guidelines └── .env # Environment variables (create from .env.example)

# Check server health curl http://localhost:8080/health # Test with MCP client mcp run uv --directory /path/to/study-slack-remote-mcp run python server.py

Enable debug logging by checkingserver.log:

# Check what's using port 8080 lsof -i :8080 # Kill process using port 8080 if needed kill -9 $(lsof -ti:8080)

-

bad_redirect_uri: Ensure the redirect URL in Slack app matches exactly:

- Must include the full path:http://localhost:8080/slack/callback
- Port must be 8080 (MCP server port)

invalid_client_id: Verify SLACK_CLIENT_ID in .env

Token not found: Complete OAuth by authorizing in browser

- OAuth tokens are mapped between MCP tokens and Slack tokens
- Tokens stored in memory locally, DynamoDB in production
- Dynamic client registration supports various MCP clients
- OAuth callbacks use HTTPS in production (App Runner)
- Fork the repository
- Create a feature branch
- Follow the guidelines in CLAUDE.md
- Submit a pull request

MIT License - see LICENSE file for details

- MCP Documentation
- MCP Python SDK
- Slack API Documentation

Wavix is a global communications platform offering APIs for voice, SMS, 2FA, and phone numbers. Our MCP server brings these capabilities to AI agents and agentic workflows.