Coder Slackbot Example

Sendbird fork. This fork applies Sendbird's internal-app security policy on top of the upstream example. Before reusing it, read sendbird_override.md: it lists the controls already enforced in code (fail-closed caller allowlist, channel pinning for model tools, no email exposure to the LLM) and the intent-dependent decisions you must make (caller scope, channel-history scopes, secrets storage) before submitting the app for security review.

This is a minimal example of a Go Slackbot that uses the Coder chat API's dynamic tools feature to let an LLM interact with Slack. It is intended as a starting point — fork it, customize the system prompt, and add your own tools.

How It Works

1. Bot is @mentioned in Slack
2. Creates a new Coder chat with dynamic tools (slack_send_message, slack_react_to_message, etc.)
3. When the LLM calls a dynamic tool → executes it against the Slack API → submits results back
4. Chat resumes until complete

Follow-up mentions in the same thread reuse the same Coder chat.

Dynamic Tools

Tool	Description
slack_send_message	Post a message
slack_edit_message	Edit a previously sent message
slack_react_to_message	Add or remove an emoji reaction
slack_get_thread_replies	Read thread context
slack_get_user_info	Look up a Slack user
slack_report_status	Update the typing indicator

Running

export SLACK_BOT_TOKEN="xoxb-..."        # Bot User OAuth Token
export SLACK_APP_TOKEN="xapp-..."        # App-Level Token (socket mode)
export CODER_URL="https://your-coder.example.com"
export CODER_SESSION_TOKEN="..."         # coder tokens create

# Caller authorization (Sendbird fork, fail-closed): one of the two is required.
export SLACK_ALLOWED_USER_IDS="U012ABCDEF,U034GHIJKL"  # who may trigger the bot
# export SLACK_ALLOW_ALL_USERS=true                    # or intentionally open to all

go build -o slackbot .
./slackbot

Slack App Setup

1. Create a Slack app at https://api.slack.com/apps (or use the manifest in slack-app-manifest.yaml)
2. Enable Socket Mode (generates the xapp- token)
3. Subscribe to bot events: app_mention
4. Add bot scopes: app_mentions:read, chat:write, reactions:write, users:read, assistant:write — plus channels:history/groups:history only if thread reading is needed (see sendbird_override.md)
5. Install to workspace

Requirements

• Coder: commit 76d89f59af42 or later (the first commit with the WatchChats, UnsafeDynamicTools, and experimental chat APIs this example depends on)
• Go 1.24+