Atlas / MCP servers / shibayu36 / Slack Explorer

Slack ExplorerCAUTION

mcp/shibayu36/slack-explorer

MCP server specialized in retrieving information from Slack messages and threads

Verdict
CAUTION
Grade
C
Trust score
75 /100
Exposed tools
—
Transport
stdio · streamable-http
License
MIT
Stars
50
01

Overview

From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.

A Model Context Protocol (MCP) server specialized in retrieving information from Slack messages and threads. It provides tools to access messages that the authenticated user can view using a User Token (xoxp).

Available Tools

  • Message Search (search_messages)
  • Search Slack messages with advanced filtering options. You can search by channel, user, date range, and specific features (reactions, files, etc.).
  • Parameters
  • query: Basic search query. Use dedicated fields for inclusion modifiers (bare modifiers in this field are rejected). Exclusion modifiers prefixed with - (e.g., -in:#channel) ARE allowed here
  • in_channel: Filter by channel name (e.g., "general", "team-dev")
  • from_user: Search messages from specific user (User ID)
  • with: Search DMs/threads with specific users (array of User IDs)
  • before, after, on: Date range filtering (YYYY-MM-DD format)
  • during: Period specification (e.g., "July", "2023")
  • has: Messages containing specific features (emoji, "pin", "file", "link", "reaction")
  • hasmy: Messages where you reacted with specific emoji
  • sort: Sort method ("score" or "timestamp")
  • count: Number of results per page (1-100, default: 20)
  • page: Page number (1-100, default: 1)
  • Thread Replies (get_thread_replies)
  • Get all replies in a message thread. Supports pagination for efficiently handling large numbers of replies.
  • Parameters
  • channel_id: Channel ID (required)
  • thread_ts: Parent message timestamp (required)
  • limit: Number of replies to retrieve (1-1000, default: 100)
  • cursor: Pagination cursor
  • User Profiles (get_user_profiles)
  • Get profile information for multiple users in bulk. Retrieve display names, real names, email addresses, and other profile information by specifying a list of user IDs.
  • Parameters
  • user_ids: Array of user IDs (required, max 100)
  • Search Users by Di
Read from source at commit e956e408db99OBSERVED · 2026-10-08
02

Connect

Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.

claude-code (oci)
claude mcp add slack-explorer-mcp:0.12.0 -- docker run -i --rm ghcr.io/shibayu36/slack-explorer-mcp:0.12.0:None
03

Trust audit

CAUTIONgrade C · trust 75/100 Install with care. The audit found things worth knowing before you trust its output.

LayerWhat it checksResult
L0Provenance & inventoryPASS
L1Static analysis of the codeWARN
L2Instruction surface (what it tells the agent)PASS
L3Class-specific surfacePASS
L4Behavioural (sandbox)SKIPPED

What the source does

Filesystem
none-observed
Network
declared (2 observation(s))
Shell
none-observed
Dependencies
pinned
Secrets in source
found

Findings (6)

MEDIUMHard-coded secrets · secret.slack · CWE-798, CWE-321
CLAUDE.md:18
SLACK_USER_TOKEN=xoxp-your-token ./slack-explorer-mcp
MEDIUMHard-coded secrets · secret.slack · CWE-798, CWE-321
README.md:86
"-e", "SLACK_USER_TOKEN=xoxp-your-token-here",
MEDIUMHard-coded secrets · secret.slack · CWE-798, CWE-321
README.md:98
-e SLACK_USER_TOKEN=xoxp-your-token-here \
MEDIUMHard-coded secrets · secret.slack · CWE-798, CWE-321
README_ja.md:86
"-e", "SLACK_USER_TOKEN=xoxp-your-token-here",
MEDIUMHard-coded secrets · secret.slack · CWE-798, CWE-321
README_ja.md:98
-e SLACK_USER_TOKEN=xoxp-your-token-here \
LOWInventory / provenance · mcp.no_tools_extracted · CWE-1104
server.json
Why it matters. the tool list is enumerated at runtime by tools/list, not declared in source
Fix. the page says so rather than showing an empty table

Gates applied: no_behavioural_pass.

Audited 2026-10-08 · audit v0.4.1 · source sha e956e408db99full audit observations/trust-audit/mcp-server/shibayu36__slack-explorer.json · Report an issue / request a re-scan
04

Audit history

Every audit this server has had. A grade with a past is a grade somebody is still checking.

DateSourceVerdictGradeScoreChange
2026-10-08e956e408db99CAUTIONC75first audit
05

Questions

What is the Slack Explorer MCP server?

MCP server specialized in retrieving information from Slack messages and threads

Is Slack Explorer safe to connect to an agent?

With care. The audit graded it C (75/100) and found 6 things worth knowing before you trust this server, listed below with the exact line each was found on.

What credentials does Slack Explorer need?

No credential environment variables were found in its source, so it appears to need none.

How does Slack Explorer run?

It speaks stdio and streamable-http, so it runs as a local process your client starts.

How current is this page?

The grade is for one exact copy of the source (e956e408db99), read on 2026-10-08. The repository is watched and re-audited when it changes.

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