# Slack MCP server

Agent View of the PolicyLayer registry record for Slack: identity, probed posture, risk grade, and all 8 tools classified. HTML page: https://policylayer.com/tools/slack

## Facts

- Server id: `@modelcontextprotocol/server-slack`
- Ref (repo): `modelcontextprotocol/server-slack`
- Install: `npx -y @modelcontextprotocol/server-slack`
- Homepage: https://github.com/modelcontextprotocol/server-slack
- Registry record: grade F, identity verified
- Lifecycle: archived
- Rate-limited: no
- Tools: 8
- Tool categories present: Read, Write
- Tags: slack
- Record last modified: 2026-08-30T01:52:06.624Z

## Tools (8)

| Tool | Category | Risk | Record |
| --- | --- | --- | --- |
| `slack_get_channel_history` | Read | Low | https://policylayer.com/tools/slack/slack-get-channel-history.md |
| `slack_get_thread_replies` | Read | Low | https://policylayer.com/tools/slack/slack-get-thread-replies.md |
| `slack_get_user_profile` | Read | Low | https://policylayer.com/tools/slack/slack-get-user-profile.md |
| `slack_get_users` | Read | Low | https://policylayer.com/tools/slack/slack-get-users.md |
| `slack_list_channels` | Read | Low | https://policylayer.com/tools/slack/slack-list-channels.md |
| `slack_add_reaction` | Write | Medium | https://policylayer.com/tools/slack/slack-add-reaction.md |
| `slack_post_message` | Write | Medium | https://policylayer.com/tools/slack/slack-post-message.md |
| `slack_reply_to_thread` | Write | Medium | https://policylayer.com/tools/slack/slack-reply-to-thread.md |

## Tool descriptions

- `slack_get_channel_history` — Get recent messages from a channel
- `slack_get_thread_replies` — Get all replies in a message thread
- `slack_get_user_profile` — Get detailed profile information for a specific user
- `slack_get_users` — Get a list of all users in the workspace with their basic profile information
- `slack_list_channels` — List public or pre-defined channels in the workspace with pagination
- `slack_add_reaction` — Add a reaction emoji to a message
- `slack_post_message` — Post a new message to a Slack channel
- `slack_reply_to_thread` — Reply to a specific message thread in Slack

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=slack · API: https://policylayer.com/registry/api · Recommended policies for every tool: https://policylayer.com/policies/slack