Slack MCP Server

An HTTP-based Model Context Protocol (MCP) server that allows MCP-compatible clients (including Claude Connectors and Strawberry Browser) to interact with a Slack workspace.

This server exposes Slack functionality (channels, messages, users, and direct messages) over the MCP protocol using a single HTTP endpoint and is designed to be deployed on Railway.

It is inspired by the original Anthropic MCP Slack example, but adapted for remote HTTP/SSE usage rather than local stdin/stdout.

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Features

• List public Slack channels
• Join existing public channels
• Create and manage public channels
• Post messages to channels
• Read channel message history
• Add and remove emoji reactions
• Read emoji reactions on messages
• Find Slack users by email or name
• Retrieve detailed user profiles
• Open and list direct message (DM) channels
• Read direct message history
• Send direct messages (DMs) to users
• Create, read, edit, and delete Slack canvases

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Requirements

• A GitHub account
• A Slack workspace where you can create apps
• A Railway account

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Slack App Setup

1. Create a Slack App

1. Go to https://api.slack.com/apps
2. Click Create New App
3. Choose From scratch
4. Select your Slack workspace

2. Configure Bot Token Scopes

Navigate to OAuth & Permissions and add the following Bot Token Scopes:

• app_mentions:read
• canvases:read
• canvases:write
• channels:read
• channels:history
• channels:join
• channels:manage
• chat:write
• im:read
• im:write
• im:history
• reactions:read
• reactions:write
• users:read
• users:read.email
• users.profile:read

These scopes are required for posting messages, reading channels, finding users, sending direct messages, managing Canvases, and other tasks possible using the MCP server.

3. Install the App to Your Workspace

1. Click Install to Workspace
2. Authorize the app
3. Copy the Bot User OAuth Token (starts with xoxb-)

4. Get Your Slack Workspace (Team) ID

1. Open Slack in a browser
2. Open any channel
3. From the URL https://app.slack.com/client/T01234ABCD/C98765432, the value starting with T is your Workspace / Team ID

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Deployment on Railway

1. Fork the Repository

1. Fork this repository into your own GitHub account

2. Deploy to Railway

1. Go to https://railway.app (sign up with my referral link if needed)
2. Click New Project
3. Choose Deploy from GitHub Repo
4. Select your forked repository
5. Railway will automatically detect the Node.js app and deploy it

3. Configure Environment Variables

In Railway, open your service and add the following Variables:

SLACK_BOT_TOKEN=xoxb-your-bot-token-here  
SLACK_TEAM_ID=T01234567

Variable	Required	Description
SLACK_BOT_TOKEN	Yes	Slack Bot User OAuth Token
SLACK_TEAM_ID	Yes	Slack Workspace / Team ID
PORT	No	Automatically set by Railway

After saving the variables, Railway will automatically redeploy the service.

4. Verify the Deployment

Once deployed, your service will be available at a Railway-generated URL. You can verify the service is running with the /health endpoint.

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MCP Endpoint

The MCP server is exposed at the following path: /sse/mcp

Your full MCP endpoint will look like: https://your-service-name.up.railway.app/sse/mcp

This endpoint handles:

• MCP initialization
• Tool calls
• Streaming responses
• Session management

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Connecting to Claude

1. Open Claude > Settings > Connectors
2. Click Add Connector
3. Choose MCP Server
4. Enter your MCP endpoint URL:https://your-service-name.up.railway.app/sse/mcp
5. Save and connect

Once connected, Claude can call Slack tools directly in chat.

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Connecting to Strawberry Browser

1. Open Strawberry > Profile Picture Menu > Settings > Integrations > Custom MCP
2. Configure Strawberry Browser to use the MCP endpoint: https://your-service-name.up.railway.app/sse/mcp

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Tools

All tools included in the server are enumerated below.

Channel & Message Tools

• slack_list_channels – List public Slack channels
• slack_join_channel – Join an existing public channel
• slack_create_channel – Create a new public channel
• slack_rename_channel – Rename an existing channel
• slack_post_message – Post a message to a channel
• slack_get_channel_history – Get recent messages from a channel
• slack_add_reaction – Add an emoji reaction to a message
• slack_remove_reaction – Remove an emoji reaction from a message
• slack_get_reactions – List reactions on a message

User & Direct Message Tools

• slack_find_user – Find users by email or name
• slack_get_user_profile – Retrieve a user’s profile information
• slack_open_dm – Open a direct message (DM) channel with a user
• slack_list_dms – List direct message channels
• slack_get_dm_history – Get message history from a DM channel
• slack_send_dm – Send a direct message to a user

Canvas Tools

• slack_canvas_create – Create a Slack canvas
• slack_canvas_get – Retrieve a Slack canvas
• slack_canvas_edit – Edit an existing Slack canvas
• slack_canvas_delete – Delete a Slack canvas

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Contributing

Issues and pull requests are welcome.

Disclaimer

I'm just a guy on the internet and you're deploying powerful code with serious implications for the privacy of your own and others' data. Please make sure that you understand this process, including its risks, completely and protect your Railway URL from exposure as this will give anyone the ability to directly access your Slack Workspace.