Slack Bot (Python Version)

A Python-based Slack bot using HTTP mode with the Slack Bolt framework that integrates with Google Gemini 2.5 Flash via OpenAI's client library.

Setup

1. Install the required dependencies:

pip install -r requirements.txt

The main dependencies are:

• slack-bolt>=1.18.0 - Slack Bot framework
• openai>=1.0.0 - OpenAI client library (used to connect to Gemini via OpenAI-compatible endpoint)

2. Configure environment variables (see Configuration section below)

3. Run the bot:

python app.py

Usage

Channel Mentions

Tag the bot in any channel to get a response:

@botname What's the weather like today?

The bot will respond to mentions with Gemini-generated responses. Currently, the bot only responds when mentioned - it does not respond to direct messages or regular channel messages.

Configuration

Required Environment Variables

The following environment variables must be set:

• SLACK_BOT_TOKEN: Your Slack bot token (starts with xoxb-)
• SLACK_SIGNING_SECRET: Your Slack signing secret for HTTP mode webhook verification
• GOOGLE_API_KEY: Your Google API key for Gemini API access

Optional Environment Variables

The following environment variables can be set to override defaults:

• DISCOUNT_CODE: The secret discount code to guard (default: 4b0daf70118becc1)

System Prompt

The system prompt is defined in prompt.py and automatically incorporates the DISCOUNT_CODE environment variable. To customize the prompt behavior, edit the get_system_prompt() function in prompt.py.

Setting Environment Variables

You can set environment variables in several ways:

1. Using a .env file (create in the project root):

SLACK_BOT_TOKEN=xoxb-your-bot-token-here
SLACK_SIGNING_SECRET=your-signing-secret-here
GOOGLE_API_KEY=your-google-api-key-here
DISCOUNT_CODE=MYSECRET

2. Using export commands (Linux/macOS):

export SLACK_BOT_TOKEN=xoxb-your-bot-token-here
export SLACK_SIGNING_SECRET=your-signing-secret-here
export GOOGLE_API_KEY=your-google-api-key-here

3. Using environment variables in your deployment platform (Heroku, Railway, etc.)

Slack App Configuration

To use this bot, you need to configure your Slack app with the following:

OAuth Scopes

Go to api.slack.com/apps → Your App → OAuth & Permissions → Scopes and add these Bot Token Scopes:

• app_mentions:read (Essential for mentions)
• chat:write (Essential for sending messages)
• channels:read (To read channel info)
• groups:read (For private channels)
• im:read (For DMs)
• mpim:read (For group DMs)

Event Subscriptions

Go to Event Subscriptions → Enable Events → Subscribe to bot events and add:

• app_mention (Essential! This is the only event the bot currently responds to)

Request URL: Set this to your deployed app URL + /slack/events (e.g., https://your-app.ondigitalocean.app/slack/events)

Notes

• HTTP Mode: Bot runs as a web server and receives events via webhooks (more production-ready than Socket Mode)
• The bot only responds to @mentions in channels - it does not respond to direct messages or regular channel messages
• Error handling is included for both Slack API and Gemini API failures
• The Gemini system prompt includes a secret guarding mechanism to protect the discount code
• Uses Google's OpenAI-compatible endpoint for cleaner integration
• If required environment variables are missing, the bot will raise an error on startup
• Public URL Required: Your app needs to be publicly accessible for Slack to send webhooks

Getting Required Credentials

Google API Key

To use this bot, you need a Google API key for Gemini:

1. Go to Google AI Studio
2. Create a new API key
3. Set it as the GOOGLE_API_KEY environment variable

Slack Signing Secret

For HTTP mode, you need the signing secret:

1. Go to api.slack.com/apps → Your App
2. Go to Basic Information → App Credentials
3. Copy the Signing Secret
4. Set it as the SLACK_SIGNING_SECRET environment variable

Security Challenge

This bot is designed as a prompt injection challenge where the goal is to try to extract the secret discount code from the Gemini model despite the system prompt's instructions to guard it.