What is slack-mcp CLAUDE.md?

Repository instructions for an MCP (Model Context Protocol) server that connects AI agents to Slack, a team messaging platform. They document available actions and example workflows for channels and messages.

Use them to create or manage Slack channels, find workspace users, post messages, reply in threads, and pin important messages.

They prevent agents from guessing how to share work with a Slack team or which steps are needed to create channels, invite people, and post updates.

How 2389-research/slack-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to 2389-research/slack-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/2389-research/slack-mcp/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/2389-research/slack-mcp

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/2389-research/slack-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/2389-research/slack-mcp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/2389-research/slack-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/2389-research/slack-mcp/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/2389-research/slack-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/2389-research/slack-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 579 This file is loaded in full into every session.

When invoked 579 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00579	$0.00579
Opus 5.5	$0.00232	$0.00232
Sonnet 5.5	$0.00116	$0.00116
Haiku 4.5	$0.00058	$0.00058

Measured 2mo ago against content hash 6ea01ab52fbc, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

slack-mcp CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Slack MCP Server

Overview

MCP server that provides Slack workspace integration. Use when you need to share content with a team, create channels for collaboration, or post messages programmatically.

Available Tools

Tool	Description
`slack_create_channel`	Create a public or private channel
`slack_invite_to_channel`	Add users to a channel by email or ID
`slack_post_message`	Post a message (markdown supported)
`slack_post_thread`	Reply in a thread
`slack_pin_message`	Pin a message to a channel
`slack_list_users`	List workspace users for ID lookup

Common Workflows

Create a GTM Review Channel

When user says "push to slack" after generating materials:

1. slack_create_channel(name: "gtm-[product]", is_private: true, description: "GTM review for [product]")
2. slack_invite_to_channel(channel_id: "...", users: ["[email protected]", "[email protected]"])
3. slack_post_message(channel_id: "...", text: "## GTM Materials: [Product]\n\n...")
4. slack_pin_message(channel_id: "...", message_ts: "...")
5. slack_post_message(channel_id: "...", text: "## Email\n\n...")
6. slack_post_message(channel_id: "...", text: "## Blog Post\n\n...")
7. slack_post_message(channel_id: "...", text: "## Tweet Thread\n\n...")

Post Updates to Existing Channel

1. slack_post_message(channel_id: "...", text: "Updated draft:\n\n...")

Discuss in Thread

1. slack_post_thread(channel_id: "...", thread_ts: "...", text: "What about this angle?")

Message Formatting

Slack uses its own markdown variant:

*bold* for bold
_italic_ for italic
`code` for inline code
> for quotes
• for bullet points

2389 Default Users

When creating GTM review channels, always invite:

[email protected] (Harper Reed)
[email protected] (Dylan Richard)

Error Handling

Common errors:

channel_not_found - Channel ID is invalid
already_in_channel - User already in channel (not a failure)
user_not_found - Email not found in workspace
not_in_channel - Bot not in channel (needs to be invited first)

Read the full file on GitHub · 74 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 74 lines · 579 tokens per session scan A 6ea01ab52fbc

Subscribe to this mod's changes

slack-mcp CLAUDE.md is an instructions file published in the GitHub repository 2389-research/slack-mcp (1 stars, last pushed 1mo ago), licensed MIT. It adds 579 tokens to every session, about $0.0023 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Collaboration channels communication mcp messaging slack

slack-mcp CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
slack-mcp CLAUDE.md2389-research/slack-mcp	Instructions file	1	1mo ago	MIT	A	579	Claude Code
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slack-mcp: Instructions file for Claude Code