ChatGPT for Slack Bot

Intercepts messages posted in Slack channels and direct messages using the Slack Bot API event subscriptions, routes them to ChatGPT via the OpenAI API, and returns responses back to the originating channel. Uses Slack's event-driven webhook architecture to listen for message.app_mention and message.im events, maintaining stateless request-response cycles with built-in retry logic for failed API calls.

Transforms Slack message text into OpenAI Chat Completion API requests with configurable system prompts and model parameters, then parses JSON responses to extract the assistant's text content. Handles API authentication via bearer token, manages request timeouts, and implements error handling for malformed responses or API failures with fallback error messages.

Manages OAuth 2.0 authentication flow for Slack app installation, requesting and storing bot tokens with minimal required scopes (chat:write, app_mentions:read, im:history). Uses Slack's app manifest configuration to declare permissions upfront, reducing user friction during installation and ensuring the bot only has access to necessary Slack APIs.

Maintains conversation context within Slack message threads by tracking parent message IDs and thread timestamps, allowing multi-turn exchanges where each response is posted as a thread reply. Implements thread-aware message routing so follow-up questions in the same thread are associated with prior context, though context is not persisted across thread boundaries or sessions.

Detects and routes direct messages to the bot using Slack's message.im event type, ensuring DM conversations are isolated from channel conversations and processed with the same LLM pipeline. Implements user-level message routing so each user's DMs are handled independently without cross-user context leakage.

Exposes OpenAI model selection (GPT-3.5-turbo, GPT-4, etc.) and inference parameters (temperature, max_tokens, top_p) as configuration variables, allowing operators to tune bot behavior without code changes. Typically implemented via environment variables or configuration files that are read at bot startup and applied to all API requests.

Implements error handling for common failure modes (API timeouts, rate limits, malformed responses, network errors) with fallback messages posted to Slack. Uses try-catch blocks around API calls and implements basic logging to help operators diagnose issues without exposing raw errors to end users.

Validates incoming Slack events using HMAC-SHA256 signature verification with the bot's signing secret, ensuring requests originate from Slack and haven't been tampered with. Implements timestamp validation to prevent replay attacks, rejecting events older than 5 minutes. This security layer runs before any message processing occurs.