Slack Bot Microservice

Description

This project is a TypeScript microservice that automates Slack delivery from templates stored in Supabase. The typical flow: load templates and credentials, run BigQuery SQL (scoped by company), build HTML tables with conditional formatting, render PNGs with Puppeteer, upload images to Google Cloud Storage, and replace placeholders (such as {{visualization_url}}) in Slack Block Kit payloads before posting. Scheduling uses cron + timezone, asynchronous processing with BullMQ and Redis, a Fastify API with Zod validation, and observability via Prometheus (/metrics) and health checks.

Stack

• Node.js 20+, TypeScript, Fastify
• BullMQ + Redis (repeatable jobs and on-demand execution)
• Supabase (messages, templates, schedules, tokens)
• BigQuery, GCS, Slack Web API
• Puppeteer for HTML-to-image rendering
• Jest for tests

First steps

cd slack-bot-microservice
npm install
cp .env.example .env
# Fill in Redis, Supabase, GCP, GCS, Slack tokens, etc.
npm run dev

API overview

Main routes (most require Bearer authentication):

• GET /health — service status
• GET /metrics — Prometheus metrics
• POST /jobs — create, update, or disable a scheduled job (cron + timezone)
• POST /execute-slack-message — enqueue an immediate run (full pipeline)
• POST /send-message-simple — send a message by messageId (handy for testing)
• POST /test-sql — run BigQuery SQL without posting to Slack
• GET /debug-template/:messageId — inspect a template for debugging

Schedule a job (example)

curl -X POST "http://localhost:8080/jobs" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <SUPABASE_SERVICE_ROLE_KEY>" \
  -d '{
    "scheduleId": "YOUR-SCHEDULE-UUID",
    "cron": "0 9 * * 1-5",
    "timezone": "America/New_York",
    "status": "enabled",
    "payload": {}
  }'

Technical highlights

• Queues and workers: separate workers for general jobs and Slack message execution; recovery of active jobs on startup.
• Slack threads: parent messages with ordered child replies via position.
• Visualization: viz_config_json controls alignment, number/currency/percent formats, and conditional color scales on cells.
• Deployment: Google Cloud Run with a Puppeteer image (Dockerfile.puppeteer); min-instances so workers are not scaled to zero.