Slack Channel

The Slack-native governance substrate for Claude Code — the kernel other governance tooling builds on. Humans, Claude Code sessions, and peer agents converse safely in shared channels: every tool call passes through a declarative, tier-aware policy engine; every decision lands in a hash-chained, Ed25519-signed audit journal you can verify offline. Per-thread session isolation, identity-aware permission gates, operator admin commands with cross-channel approval, multi-agent loop control + backpressure, lease-fenced sessions that survive a process crash with loss-proof reply delivery, and defense-in-depth against prompt injection. The policy/journal/relay kernel here is the substrate that the companion agent-governance-plane (AGP) reimplements for cross-runtime governance.

Links: Roadmap & Scope · Gist One-Pager · GitHub Pages · Release Notes

> Research Preview — Channels require Claude Code v2.1.80+ and claude.ai login.

How It Works

Slack workspace (cloud)
    ↕ WebSocket (Socket Mode — outbound only, no public URL)
server.ts (local MCP server, spawned by Claude Code)
    ↕ stdio (MCP transport)
Claude Code session

Socket Mode means no public URL needed — works behind firewalls, NAT, anywhere.

Quick Start

For AI-assisted setup: run /slack-channel:install and your AI assistant will walk you through every step below. The install skill also supports doctor (health check), verify (round-trip test), repair (auto-fix), manifest (one-click Slack-app import), reset, tour, and uninstall modes — see skills/install/SKILL.md.

Prerequisites

Before step 1, confirm you have:

• Bun ≥ 1.0 — install with curl -fsSL https://bun.sh/install | bash. Node.js / Docker fallbacks are documented in Option B / Option C below.
• Claude Code ≥ v2.1.80 — see https://docs.claude.com/claude-code/install for upgrade.
• claude.ai login — this is a Research Preview constraint. API-key-only auth (ANTHROPIC_API_KEY set with no claude.ai session) does NOT work for Channels. Run claude login to complete the browser flow.

1. Create a Slack App

1. Go to api.slack.com/apps → Create New App → From scratch
2. Socket Mode: Settings → Socket Mode → Enable → Generate App-Level Token (xapp-...) with connections:write scope
3. Event Subscriptions: Enable → Subscribe to bot events:

• message.im — DMs
• message.channels — public channels
• message.groups — private channels
• app_mention — @ mentions

1. Bot Token Scopes (OAuth & Permissions):

• chat:write — send messages
• channels:history — read public channels
• groups:history — read private channels
• im:history — read DMs
• reactions:write — add reactions
• files:read — download shared files
• files:write — upload files
• users:read — resolve display names

1. Install to Workspace → Copy Bot Token (xoxb-...)

2. Configure Tokens

/slack-channel:configure xoxb-your-bot-token xapp-your-app-token

3. Run

Pick your runtime:

Option A: Bun (recommended)

bun install
# Current (claude-code-plugins marketplace):
claude --channels plugin:slack-channel@claude-code-plugins
# Future (after upstream approval):
# claude --channels plugin:slack-channel@claude-plugins-official

Option B: Node.js / npx

npm install
# In .mcp.json, change command to: "npx", args: ["tsx", "server.ts"]
claude --channels plugin:slack-channel@claude-code-plugins

Option C: Docker

docker build -t claude-slack-channel .
# In .mcp.json, change command to: "docker", args: ["run", "--rm", "-i", "-v", "~/.claude/channels/slack:/state", "claude-slack-channel"]
claude --channels plugin:slack-channel@claude-code-plugins

3.5. Add the bot to your Slack channel

This step is the most common silent failure. Slack installs apps to the workspace without joining any channels. The pairing DM in step 4 works because DMs auto-route, but a channel test message in step 5 will hit silence — the bot literally isn't in the channel to see the event.