Slack (mindstone) MCP Server
@mindstone/mcp-server-slack
npm
v0.3.0
Source verified
Published by mindstone — publish provenance cryptographically ties this package to that repository. That is proof of origin, not an official vendor package.
Slack workspace MCP server covering channels, messages, threads, reactions, users, files, bookmarks, and message scheduling via the Slack Web API.
The grade answers one question — how safe is this server for you to adopt — so it is computed in two auditable stages. Nothing below is an opinion or an LLM's guess; every line is a real term the deterministic engine applied, and the same input always yields the same number.
1. Threat score — 100 − 0 = 100. What the published surface and source actually contain:
The deterministic scan raised no scored threat in the surface it inspected — the threat score stayed at 100. Capability observations and advisory notes are recorded but never lower it.
2. Client adoption risk — 100 − 3 = 97. Three small, subtract-only factors that reflect your risk in adopting it — a clean scan proves less on a powerful, unverified or barely-inspectable package, so the grade says so plainly:
| Points | Adoption-risk factor |
|---|---|
| −3 | capability blast radius (moderate) — client exposure if the model is manipulated |
Capability observations and info notes are shown under Findings but never scored.
Open any row's finding below for the file, line and evidence behind a deduction.
Findings 3
medium Hardcoded egress to an external endpoint (dist/tokenProvider.js)MTC-SRC-003
In the server's implementation (`dist/tokenProvider.js:363`): A hardcoded outbound call to a fixed external host inside server code is a classic exfiltration/telemetry channel — especially paired with reads of local data. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: onse = await globalThis.fetch('https://slack.com/api/oauth.v2.access', { method: 'POST',
Fix: Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.
Location: server dist/tokenProvider.js
medium Unconstrained URL/host parameter "file_url" on "download_slack_file"MTC-CAP-007
Tool "download_slack_file" takes a URL/host parameter "file_url" with no allowlist/pattern. An outbound-request tool with an unbounded destination enables SSRF and cloud-metadata access (e.g. 169.254.169.254).
Fix: Allowlist destinations or constrain the parameter; block private/link-local addresses server-side.
Location: tool download_slack_file · inputSchema.properties.file_url
medium Unconstrained URL/host parameter "url" on "get_slack_message_by_link"MTC-CAP-007
Tool "get_slack_message_by_link" takes a URL/host parameter "url" with no allowlist/pattern. An outbound-request tool with an unbounded destination enables SSRF and cloud-metadata access (e.g. 169.254.169.254).
Fix: Allowlist destinations or constrain the parameter; block private/link-local addresses server-side.
Location: tool get_slack_message_by_link · inputSchema.properties.url
Tools 39
Each tool and what it can reach — statically extracted from the published source.
download_slack_fileingests untrusted inputget_slack_channel_historyingests untrusted inputget_slack_message_by_linkingests untrusted inputget_slack_thread_repliesingests untrusted inputget_slack_unread_messagesingests untrusted inputlookup_user_by_emailingests untrusted inputadd_slack_bookmarkno sensitive capabilityadd_slack_reactionno sensitive capabilityadd_slack_reminderno sensitive capabilityauthenticate_slack_workspaceno sensitive capability
Show 29 more tools ↓
complete_slack_reminderno sensitive capabilitycompose_slack_messageno sensitive capabilitycreate_slack_channelno sensitive capabilitydelete_scheduled_slack_messageno sensitive capabilitydelete_slack_messageno sensitive capabilitydelete_slack_reminderno sensitive capabilityget_slack_saved_messagesno sensitive capabilityget_slack_user_profileno sensitive capabilityinvite_user_to_channelno sensitive capabilitylist_scheduled_slack_messagesno sensitive capabilitylist_slack_bookmarksno sensitive capabilitylist_slack_channelsno sensitive capabilitylist_slack_emojino sensitive capabilitylist_slack_pinsno sensitive capabilitylist_slack_remindersno sensitive capabilitylist_slack_usersno sensitive capabilitylist_slack_workspacesno sensitive capabilitymark_slack_channel_as_readno sensitive capabilityopen_slack_dmno sensitive capabilitypin_slack_messageno sensitive capabilitypost_slack_messageno sensitive capabilityremove_slack_reactionno sensitive capabilityreply_to_slack_threadno sensitive capabilityschedule_slack_messageno sensitive capabilitysearch_slack_messagesno sensitive capabilitysend_myself_a_noteno sensitive capabilityunpin_slack_messageno sensitive capabilityupdate_slack_messageno sensitive capabilityupload_slack_fileno sensitive capability
What this scan could not see
- Tools were statically extracted from the published source (39 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command "npx -y <package>".
Versions 3
Scan history per published version. The engine is deterministic — the same version always yields the same score, so a changed score means the package itself changed.
| Version | Score | Findings | Engine | Scanned |
|---|---|---|---|---|
v0.3.0 latest |
A 97/100 | 3 | 1.13.0 | 2026-08-25 |
v0.2.0 |
A 97/100 | 3 | 1.12.1 | 2026-07-31 |
v0.1.6 |
A 97/100 | 3 | 1.12.1 | 2026-07-27 |
Embed this score
Show this server's live Trust Score in your README, docs or website. The badge is served straight from the registry and updates automatically after every rescan — no API key needed. It links back to this page, so anyone who sees the grade can also read the findings behind it instead of taking a number on faith.
Verify this score yourself
The score above is reproducible: the same package version always yields the same result. Run it locally or over the free API — no account, no LLM, fully deterministic.
npx mcptrustchecker scan @mindstone/mcp-server-slack --onlineOther implementations of Slack 29
Independent packages implementing the same tool, scanned with the same engine. Compare all 30 side by side →
User-token (xoxp) Slack MCP server over stdio
Integrate the Slack Web API into agentic workflows via MCP
MCP server for Slack Web API — send messages, manage channels, search, reactions, files, pins, bookmarks, and more through 38 tools
MCP server for the Slack **Web API**, acting as a bot user (`xoxb-` token). A good fit for internal team notifications and reports.
Channel lookup, history, and messaging tools for Slack workspaces.
MCP Server for Slack API integration
More in Productivity & Workflow
MCP AgentChat - 让 AI Agent 通过 Telegram 与用户实时交互：发送消息、图片，等待用户回复
A Model Context Protocol (MCP) server for Airthings Air Quality Monitor devices.
MCP server for Anki
TypeScript package for reading and searching Apple Notes on macOS via direct SQLite access. Includes markdown conversion, attachment support, and offers a local MCP server!
Verified biotech catalyst calendar (PDUFA/AdComm/trial readouts) anchored to official sources.
Appointment booking platform letting agents check provider availability and create bookings.