Slack MCP Server

Give your AI agents full Slack access — messages, threads, DMs, channels, canvases, reactions, and search. 27 tools over the Slack Web API with enterprise governance and audit-ready risk classification.

Architecture

Tools (27)

Tool	Purpose	Risk Class
`list_channels`	List public and private channels	Read-only
`list_channels_paginated`	List channels with cursor pagination	Read-only
`get_channel_history`	Get recent messages from a channel	Read-only
`get_history_paginated`	Get history with cursor pagination	Read-only
`get_thread`	Get thread replies for a message	Read-only
`search_messages`	Search messages across all channels	Read-only
`list_users`	List workspace users	Read-only
`get_user`	Get user profile info by ID	Read-only
`list_members`	List members of a channel	Read-only
`list_dms`	List direct message conversations	Read-only
`list_emoji`	List custom emoji in the workspace	Read-only
`list_files`	List files shared in a channel	Read-only
`get_file`	Get file metadata and download URL	Read-only
`read_canvas`	Read/export a canvas as markdown	Read-only
`list_bookmarks`	List bookmarks in a channel	Read-only
`list_scheduled_messages`	List scheduled (draft) messages	Read-only
`send_message`	Send a message to a channel or thread	External write
`open_dm`	Open a DM conversation with users	External write
`add_reaction`	Add an emoji reaction to a message	External write
`set_channel_topic`	Set a channel's topic	External write
`upload_file`	Upload a text file to a channel	External write
`create_channel`	Create a new public or private channel	External write
`create_canvas`	Create a rich document in a channel	External write
`update_canvas`	Update canvas content (markdown)	External write
`add_bookmark`	Add a bookmark link to a channel	External write
`schedule_message`	Schedule a message for future delivery	External write
`delete_scheduled_message`	Cancel a scheduled message	External write

Comparison with Other Slack MCP Servers

Feature	Slack Official	korotovsky/slack-mcp	Ours
Thread replies (read)	✅	✅	✅
DMs / Group DMs	✅	✅	✅
Canvases (create/read/update)	✅	❌	✅
Create channel	✅	✅	✅
List channel members	✅	✅	✅
Custom emoji list	✅	❌	✅
Send messages + threads	✅	✅	✅
Reactions	✅	✅	✅
Search	✅	✅	✅
File upload + reading	✅	❌	✅
Draft/scheduled messages	✅	❌	✅
Bookmarks	❌	✅	✅
Pagination (cursor)	✅	✅	✅
OAuth/user tokens	✅	✅ (cookie)	Bot token
Registry governance	❌	❌	✅
Risk classification	❌	❌	✅
HealthCheck trait	❌	❌	✅
Rust / single binary	❌ (Node)	❌ (Node)	✅

Installation

Build from source

git clone https://github.com/zavora-ai/mcp-slack
cd mcp-slack
cargo build --release

From crates.io

cargo install mcp-slack

Configuration

Environment Variables

Variable	Required	Description
`SLACK_BOT_TOKEN`	✅	Bot User OAuth Token (`xoxb-...`)
`SLACK_TOKEN`	Alternative	Alias for `SLACK_BOT_TOKEN`
`RUST_LOG`	❌	Log level (default: `info`)

Required Bot Token Scopes

channels:read        — list channels
channels:history     — read messages
channels:manage      — set topic
groups:read          — private channels
groups:history       — private channel messages
chat:write           — send messages
reactions:write      — add reactions
search:read          — search messages
users:read           — list/get users
files:write          — upload files
channels:join        — self-join channels (optional)

Slack App Manifest

display_information:
  name: MCP Slack Bot
  description: AI agent access to Slack via MCP protocol
features:
  bot_user:
    display_name: MCP Bot
    always_online: true
oauth_config:
  scopes:
    bot:
      - channels:read
      - channels:history
      - channels:manage
      - groups:read
      - groups:history
      - chat:write
      - reactions:write
      - search:read
      - users:read
      - files:write
settings:
  org_deploy_enabled: false
  socket_mode_enabled: false
  token_rotation_enabled: false

Client Configuration

Claude Desktop

{
  "mcpServers": {
    "slack": {
      "command": "mcp-slack",
      "args": [],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token"
      }
    }
  }
}

Kiro

Add to .kiro/settings/mcp.json:

{
  "mcpServers": {
    "slack": {
      "command": "mcp-slack",
      "args": [],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token"
      }
    }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "slack": {
      "command": "mcp-slack",
      "args": [],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token"
      }
    }
  }
}

Codex (OpenAI)

{
  "mcpServers": {
    "slack": {
      "command": "mcp-slack"
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "slack": {
      "command": "mcp-slack",
      "args": [],
      "env": {
        "SLACK_BOT_TOKEN": "xoxb-your-token"
      }
    }
  }
}

Quick Start

# Set token
export SLACK_BOT_TOKEN="xoxb-your-token"

# Verify token works
curl -s -H "Authorization: Bearer $SLACK_BOT_TOKEN" https://slack.com/api/auth.test

# Run server
mcp-slack

Test with MCP Inspector

npx @modelcontextprotocol/inspector mcp-slack

Usage Examples

List channels

"List my Slack channels"
→ calls list_channels

Read a thread

"What did the team say in the thread about the deployment?"
→ calls search_messages → get_thread

Send a message

"Post in #engineering: the release is ready for QA"
→ calls send_message with channel + text

Reply in a thread

"Reply to that message saying I'll review it"
→ calls send_message with thread_ts

Open a DM

"Send a DM to James asking about the PR"
→ calls open_dm → send_message

Create a channel

"Create a private channel called project-alpha"
→ calls create_channel with is_private=true

MCP Server Manifest

server_id = "mcp_slack"
display_name = "Slack"
version = "1.3.0"
domain = "collaboration"
risk_level = "medium"
writes_allowed = "gated"
transports = ["stdio"]
credentials = ["vault://slack-bot-token"]

Testing

# Build
cargo build

# Run tests
cargo test

# Integration test (requires SLACK_BOT_TOKEN)
echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test","version":"1.0"}}}
{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"list_channels","arguments":{"limit":5}}}' | cargo run

Roadmap

OAuth user token support (for user-level access beyond bot)
Workflow triggers (workflows.triggers.create)
Pin messages (pins.add, pins.list)
User presence/status (users.setPresence, users.profile.set)

Registry Compliance

This server implements the ADK MCP SDK contract:

HealthCheck — async health probe for registry monitoring
mcp-server.toml — manifest declaring tools, risk classes, and credentials
Structured tracing — RUST_LOG env-filter for observability

Contributors

_{James Karanja Maina}

License

Apache-2.0 — see LICENSE for details.

Part of the ADK-Rust Enterprise MCP server ecosystem.

Built with ❤️ by Zavora AI

rmcp and MCP compatibility

This server is built with rmcp 3.1.2 and requires Rust 1.94.1 or newer. The rmcp 3 rollout retains legacy MCP initialization compatibility and targets MCP protocol revisions 2025-11-25 and 2026-07-28.

MCP 2026-07-28 rollout (P4 workflow/business)

This server uses rmcp 3.1.2 and adk-mcp-sdk 0.2 with a minimum supported Rust version of 1.94.1. It accepts stateless MCP 2026 requests with per-request protocol, client identity, and capability metadata while retaining the legacy MCP 2025-11-25 initialize flow for ordinary tools.

Tasks: upload_file
MRTR approvals: send_message, upload_file
Discovery and routing: rmcp serves on-demand discovery and validates the per-request protocol envelope; HTTP deployments can route with Mcp-Method and Mcp-Name. The packaged binary currently uses stdio.
Caching: tools/list returns a public ttlMs of 60,000 for MCP 2026; rmcp omits the cache fields for legacy clients.
Deprecated extensions: this server does not add new Roots, Sampling, or dynamic client-registration dependencies.

Protected tools require MCP_REQUEST_STATE_KEY with at least 32 high-entropy bytes. All replicas must share that key so sealed approval state can resume on another instance. Approval state is bound to the client identity, tool, and arguments and expires after two minutes. Missing identity, invalid state, rejection, or legacy protocol use fails closed. Task records are process-local for the current stdio runtime; use a durable task store before deploying the server behind scale-to-zero HTTP infrastructure.

Name		Name	Last commit message	Last commit date
docs/assets		docs/assets
src		src
.gitignore		.gitignore
Cargo.toml		Cargo.toml
LICENSE		LICENSE
README.md		README.md
mcp-server.toml		mcp-server.toml

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Slack MCP Server

Architecture

Tools (27)

Comparison with Other Slack MCP Servers

Installation

Build from source

From crates.io

Configuration

Environment Variables

Required Bot Token Scopes

Slack App Manifest

Client Configuration

Claude Desktop

Kiro

Cursor

Codex (OpenAI)

Windsurf

Quick Start

Test with MCP Inspector

Usage Examples

List channels

Read a thread

Send a message

Reply in a thread

Open a DM

Create a channel

MCP Server Manifest

Testing

Roadmap

Registry Compliance

Contributors

License

rmcp and MCP compatibility

MCP 2026-07-28 rollout (P4 workflow/business)

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