Slack MCP

What it does

The Slack MCP Server connects Claude to your Slack workspace via the Slack Web API, making your AI assistant a fully capable Slack participant. Claude can read message history, post new messages, reply in threads, search across all channels, and look up information about users and channels — turning Slack from a passive data store into an active workspace Claude can reason about and write to.

Common use cases include daily digests (summarize all messages in #engineering since yesterday), incident analysis (search Slack for all messages mentioning a specific error code), standup drafting (pull what you worked on from your DMs and channels), and automated notifications (have Claude post a formatted summary to a channel after completing a task).

• List all public channels and their member counts
• Read message history from any channel or DM thread
• Post messages to channels with full Block Kit formatting support
• Reply to threads by message timestamp
• Search messages across all channels with Slack's query language
• Look up user profiles by name, email, or user ID
• Get channel info including topic, purpose, and pinned messages
• React to messages with emoji

How to connect

Create a Slack app at api.slack.com/apps, add a Bot Token Scope, and install it to your workspace. Copy the xoxb- Bot User OAuth Token from the OAuth & Permissions page.

export SLACK_BOT_TOKEN="xoxb-your-token-here"
export SLACK_TEAM_ID="T0123456789"  # optional, limits to one workspace
claude mcp add slack -- npx -y @modelcontextprotocol/server-slack

Required OAuth scopes

When creating your Slack app, add the following Bot Token Scopes under OAuth & Permissions:

• channels:read — list public channels
• channels:history — read messages in public channels
• chat:write — post and reply to messages
• search:read — search messages across channels
• users:read — look up user profiles
• groups:read and groups:history — for private channel access (optional)
• im:read and im:history — for DM access (optional)

Available tools

• slack_list_channels — list all channels the bot has access to
• slack_get_channel_history — read recent messages in a channel
• slack_post_message — send a message to a channel or user
• slack_reply_to_thread — post a reply within an existing thread
• slack_search_messages — search messages using Slack query syntax
• slack_get_user_info — retrieve a user's profile and status
• slack_add_reaction — react to a message with an emoji
• slack_get_channel_info — fetch channel metadata including topic

Example usage

Ask Claude to summarize all important messages from a channel and post a digest:

# User prompt
Read the last 100 messages in #incidents, identify
any unresolved issues, and post a summary to
#engineering-digest with action items.

slack_get_channel_history({ channel: "#incidents", limit: 100 })
→ returns 100 messages
→ Claude identifies 3 unresolved threads
slack_post_message({
  channel: "#engineering-digest",
  text: "*Incident Summary — 3 open items*\n..."
})
→ digest posted successfully