Iris

Slack ⇄ Claude Code bridge — minimal, self-hosted.

Iris connects a Slack workspace to a local Claude Code CLI. You talk to Claude from a Slack thread or DM; Iris runs Claude Code as a resident process, streams its output back, and turns tool-permission requests into clickable Slack buttons.

It is a deliberately small, single-purpose tool — Slack + Claude Code only — with no plugin registry, no multi-platform/multi-agent abstraction, no provider switching, cron, relay, or TTS.

Named after Iris, the Greek messenger goddess of the rainbow who relays between gods and mortals.

Acknowledgements

Iris is inspired by cc-connect (MIT), an excellent general-purpose bridge that connects many AI coding agents to many messaging platforms. We are grateful for its design ideas.

Iris is not a fork — it is an independent implementation that distills those ideas down to a single combination (Slack + Claude Code) for a smaller, more auditable tool. What we borrowed is the approach (driving Claude Code over stream-json, bridging the stdio permission tool to chat buttons, the NO_REPLY silence marker); what we dropped is everything that exists to support the other 100+ agent×platform combinations. If you need broad multi-platform / multi-agent support, use cc-connect.

Built with Claude Code

The entire source code of Iris was written by Claude Code (Anthropic's agentic coding tool) — from the initial analysis of cc-connect, through design, implementation, tests, CI/CD, release automation, and the signed/notarized macOS binary. It is, fittingly, a tool for Claude Code that was itself built by Claude Code.

How it works

Slack (Socket Mode) ──▶ index.ts ──▶ session.ts ──▶ claude.ts ──▶ claude CLI
   ▲   block_actions                  thread_ts          stream-json (stdin/stdout)
   └──── chat.postMessage ◀── format.ts ◀──────────────── events

• One Slack thread (or DM) = one Claude session = one resident process.
• Claude runs with --input-format stream-json --output-format stream-json --permission-prompt-tool stdio. Iris writes user messages / permission responses to stdin and parses the JSON event stream from stdout.
• Permission requests (control_request → can_use_tool) become Block Kit Allow/Deny buttons; the click is routed back via control_response.
• When a process dies, its session_id is kept so the next message resumes it with --resume.

Features

• Channel (@mention + thread) and DM conversations; one thread = one session
• Tool-permission buttons; permission modes (manual / acceptEdits / auto)
• Streaming incremental updates; usage footer (tokens / cost / duration)
• Inbound image & file attachments (images seen directly, files read)
• Outbound generated-file uploads
• Slash commands (/help /status /sessions /restart /clear /switch /resume /summary /cc:)
• /switch <name> to change the working directory per session (searches under work_dir)
• /resume lists past Claude sessions (with turn count & recent prompts); /resume <id> reattaches the thread
• /summary summarizes the current conversation for handover (output wrapped in a code block); /summary <request> uses your own instruction
• /cc:<command> [args] runs Claude Code's own /<command> (custom commands / skills are expanded in stream-json mode; built-in interactive commands like /context /compact are not available headless)
• Multi-project routing via TOML
• Leveled logging (log_level), iris --version

Install

Option A — standalone binary (recommended, no Node required)

Download the latest binary for your platform from Releases:

| Platform | Asset | Notes | |----------|-------|-------| | macOS arm64 | iris-macos-arm64.zip | Apple-signed and notarized | | Linux x86_64 | iris-linux-x64.tar.gz | | | Linux arm64 | iris-linux-arm64.tar.gz | AWS Graviton, Raspberry Pi, etc. | | Windows x86_64 | iris-windows-x64.zip | |

# macOS / Linux
tar xzf iris-linux-x64.tar.gz   # or unzip iris-macos-arm64.zip
mv iris /usr/local/bin/iris
iris --help

# Windows (PowerShell)
Expand-Archive iris-windows-x64.zip -DestinationPath .
.\iris.exe --help

Option B — npm

npm install -g @t2tx/iris

Iris launches the claude CLI; it does not handle API keys itself. The claude CLI must already be authenticated.

Configuration (TOML)

Generate a starter config with iris init, then fill in your tokens and check it:

iris init           # write a commented config (~/.iris-slack/config.toml, mode 0600; never overwrites)
# → edit it: [slack] tokens + at least one [[projects]]
iris config check   # validate without starting (prints a per-project summary)
iris config path    # show which config file is used

All configuration lives in one TOML file, resolved in this order:

1. IRIS_CONFIG=<path>
2. ./iris.config.toml (repo-local — development)
3. ~/.iris-slack/config.toml (installed default)

# Top-level keys must come BEFORE [slack] / [[projects]] table headers.
permission_mode = "manual"   # manual | acceptEdits | auto
log_level = "info"           # debug | info | warn | error

[slack]
bot_token = "xoxb-..."
app_token = "xapp-..."

[[projects]]
name = "default"
work_dir = "/path/to/your/repo"
allow_channels = ["C0123ABCDEF"]   # respond to @Iris in this channel
allow_users = ["U09XXXXXXX"]       # respond to this user's DMs

• Routing: an inbound message matches the first project whose allow_channels (channel) / allow_users (DM) include it; no match → ignored.
• Add multiple [[projects]] for different work dirs / permission modes per channel or user. Template: iris.config.example.toml.

Slack app setup walkthrough: docs/slack-setup.md (Japanese).

Run

iris            # run in the foreground (all platforms)
iris install    # install as a launchd service — macOS only (auto-start on login)
iris status     # show launchd service status — macOS only

Security notes

• Default-deny: with empty allow_channels / allow_users, Iris ignores every message.
• Manual permission mode by default: every tool use needs an explicit click. acceptEdits auto-allows edit tools; auto allows everything — opt in only if you trust the peer.
• No outbound integrations (cron/relay/provider-switch). Attack surface is just Slack-in → Claude-CLI-out.
• Tokens live only in the TOML config file — protect it (chmod 600).

Development

See CONTRIBUTING.md.

License

MIT