Slack MCP Server — Watchlist

MCP100 Assessment

Watchlist / Tracking

Why we’re tracking it

Track Slack API scopes and message or workspace tool changes

Reviewed Oct 5, 2026 · Documentation review; complete setup workflow not independently tested

Best fit

Teams automating Slack search, history retrieval and carefully scoped collaboration actions.

What we know

A community Slack MCP for messages, threads, search, channels, users, reactions and optional write actions.

Maintenance / activity evidence

Observed May 14, 2026 (UTC)Remove maintainer note from configuration documentation

Tracking evidence observed Oct 5, 2026. These dated signals do not establish current maintenance. Reviewed enrichment confidence: high.

Activity source · commits ↗Activity source · releases ↗

Verification gaps / watch-outs

Installation and comprehensive security have not been independently audited.
Token scopes and channel membership. Writes: Post messages; Reactions; Mark read; User-group changes when enabled.
Slack tokens; optional server bearer key
Sensitive access: DMs, Messages, User profiles, Slack tokens

Slack data and external messaging are sensitive; use narrow token scopes and keep write tools disabled unless explicitly needed.

Security source · repository notice ↗Security source · policy file ↗

Full authority, access and evidence limits are available in Review context and Access & risk.

Popularity

1,859 repository stars · 113.5k package downloads / 30 days

Stars observed Oct 6, 2026. Downloads observed Oct 6, 2026.

All limitations / Review context

Which Slack operations and authentication scopes are documented now?

The bounded assessment reviewed the official README, repository notices, security policy path, and security page for known material public-tracking blockers. No such blocker was identified. This is a public-tracking assessment, not an installation safety certification.

Slack data and external messaging are sensitive; use narrow token scopes and keep write tools disabled unless explicitly needed.
Token scopes and channel membership.
Slack tokens; optional server bearer key
Messages/users/channels may be cached and returned to the MCP client.
Reviewed write actions: Post messages; Reactions; Mark read; User-group changes when enabled
Sensitive access: DMs, Messages, User profiles, Slack tokens
Installation, client compatibility and comprehensive security have not been independently audited. Authentication and access depend on the configured services.
No independent runtime, installation, or comprehensive security audit was performed.
No installation, runtime, client matrix, or complete tool-contract audit was performed in this review.
Token type changes available features.
Write tools are opt-in but can send external communications.

Original activity observations

2026-05-14T22:51:29Z: Remove maintainer note from configuration documentation

Technical identity

github.com/korotovsky/slack-mcp-server

Exact implementation source: https://github.com/korotovsky/slack-mcp-server ↗
Reviewed resource type: MCP Server
Repository identity: korotovsky/slack-mcp-server
Package identity: npm:slack-mcp-server
Service endpoint: 127.0.0.1:13080

Evidence & Sources

Evidence basis: Recorded source evidence
Setup runtime verification: Not independently runtime-tested by MCP100 for this setup workflow.

Reviewed Oct 5, 2026 · Latest source observation Oct 6, 2026

GitHub repository ↗
korotovsky/slack-mcp-server
Recorded repository material and project history.
Package registry ↗
slack-mcp-server
Recorded package identity, distribution or download evidence.
Includes references whose attribution is not established.

Setup · Watchlist

Install & Agents

claude-desktop

Publisher instructions with a documented client setup path.

Source evidence observed Oct 14, 2026.

Additional setup details required — see the specific gaps below.

Install / connect
Publisher instructions
Slack workspace MCP server supports stdio, SSE and HTTP, with user/OAuth and restricted posting modes.
Register Slack MCP stdio executable or publisher HTTP endpoint in the selected client using the provided README config; supply Slack OAuth token/user token as specified. Multiple transports are alternatives.
Configure / authenticate
Publisher instructions
Slack server supports stdio, SSE and HTTP with OAuth or browser-session tokens. Prefer least-privileged OAuth; do not treat stealth browser cookie reuse as an ordinary recommended authentication method.
Check connection
Suggested check
Use read-only channel listing after approved workspace authorization; never send messages to test.
Remove / uninstall / revoke
MCP100 setup guide
Only for a Claude Code registration named slack; desktop remove mcpServers.slack. Shut down any separately hosted Slack MCP service/container.
Distinguish client registration removal from software uninstall, persistent data deletion and provider OAuth/API-key revocation.
claude mcp remove slack

Official Documentation & Sources

What it does

A community Slack MCP for messages, threads, search, channels, users, reactions and optional write actions.

Capability: Communication
Resource type: MCP Server
Best fit: Teams automating Slack search, history retrieval and carefully scoped collaboration actions.

Representative uses

Read channel/DM history
Search messages/users
Inspect channel/user resources
Optionally post messages or manage reactions/user groups

Limitations

Token type changes available features.
Write tools are opt-in but can send external communications.

Reviewed access

Access & risk

Review the exact access boundary before connecting this MCP to accounts, credentials, or sensitive data.

Authentication: Slack tokens; optional server bearer key
Permissions: Token scopes and channel membership.
Data handling: Messages/users/channels may be cached and returned to the MCP client.
Cost: free
Risk and cautions: Slack data and external messaging are sensitive; use narrow token scopes and keep write tools disabled unless explicitly needed.

Access scope and cautions

Write actions: Post messages Reactions Mark read User-group changes when enabled
Sensitive access: DMs Messages User profiles Slack tokens
Risk level: high

FAQ

Based on reviewed evidence as of 2026-10-06. Watchlist tracking is not a recommendation or a security certification.

Which tasks are documented for this implementation?

The reviewed tasks include: Read channel/DM history; Search messages/users; Inspect channel/user resources; Optionally post messages or manage reactions/user groups.

What authentication is documented?

Slack token authentication; optional bearer API key for remote server.

Can it modify data or perform write operations?

Documented write actions include: Post messages; Reactions; Mark read; User-group changes when enabled. Recorded permission boundary: Token scopes and channel membership.

What data-handling boundary should I consider?

Messages/users/channels may be cached and returned to the MCP client. Recorded sensitive-access context: DMs; Messages; User profiles; Slack tokens.

What limitations and risks should I check before use?

Slack data and external messaging are sensitive; use narrow token scopes and keep write tools disabled unless explicitly needed. Token type changes available features. Write tools are opt-in but can send external communications. No independent runtime, installation, or comprehensive security audit was performed.

Is this an official MCP?

korotovsky is listed as Community implementation in MCP100’s current evidence.