Slack MCP Server
MCP server for interacting with Slack workspaces via Bot Token API
Score Breakdown
Server Info
- Package
- @modelcontextprotocol/server-slack
- Registry
- npm
- Repository
- modelcontextprotocol/servers
- Maintainer
- AnthropicVendor
- Category
- Communication
- Tags
- messagingenterprisecollaboration
- Last Scanned
- 7 Apr 2026
Findings
4 issuesAuthentication & Identity
HIGHNo per-request auth - requires instance-per-user
Stdio-only transport. Auth via SLACK_BOT_TOKEN env var (shared Bot OAuth token). SLACK_TEAM_ID is required. Optional SLACK_CHANNEL_IDS restricts which channels are visible. No MCP OAuth support. The package is DEPRECATED on npm. For multi-tenant deployment, the platform must spawn a separate server instance per user.
Add HTTP/SSE transport to accept per-request Authorization headers, or implement the MCP OAuth spec.
Tool Schema Quality
MEDIUMOnly 0 of 8 schemas have parameter constraints
Most schemas lack maxLength, enum, or pattern constraints on string parameters.
Add constraints to string parameters, especially on write operations.
Data Exposure
LOWNo field selection on responses
Responses return full records rather than projected fields.
Implement field selection to return only relevant fields.
Maintenance & Trust
MEDIUM15 dependency vulnerabilities (6 high)
npm audit found 6 high severity CVEs.
Update vulnerable dependencies.
Tools
8 total| Name | Description | Risk |
|---|---|---|
| slack_list_channels | List public or pre-defined channels in the workspace with pagination | read |
| slack_post_message | Post a new message to a Slack channel | write |
| slack_reply_to_thread | Reply to a specific message thread in Slack | write |
| slack_add_reaction | Add a reaction emoji to a message | write |
| slack_get_channel_history | Get recent messages from a channel | read |
| slack_get_thread_replies | Get all replies in a message thread | read |
| slack_get_users | Get a list of all users in the workspace with their basic profile information | read |
| slack_get_user_profile | Get detailed profile information for a specific user | read |
Deploy Slack MCP Server securely
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