Discord Schedule Bot: Coordinating Global UTC Community Events with Slash Commands & Supabase Realtime

Coordinating multiplayer matches or engineering syncs across four continents in Discord is notoriously chaotic: someone posts a time in EST, someone else replies in CET, messages scroll off-screen, and nobody knows which hour actually has a full lobby.

I built discord-schedule-bot to give distributed Discord communities a deterministic, UTC-normalized scheduling engine that works simultaneously inside Discord via Slash Commands and on the web via a live Supabase Realtime Dashboard.

Click to zoomDiscord Schedule Bot Live Web Dashboard

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1. Dual-Interface Architecture: Discord Slash Commands + Web Matrix#

The system shares a single PostgreSQL database (titles and signups tables in Supabase) across two synchronized interfaces:

1. In-Channel Discord Bot (bot.ts):
   • Built with discord.js v14, registering guild/global slash commands via scripts/register-commands.ts.
   • Running /add <hour> (0–23 UTC) or /title <event_name> inside any Discord channel records the user's availability for that specific channel's event and posts an updated embed table grouped by UTC hour and day of the week.
2. Interactive Next.js Web Dashboard (pages/dashboard.tsx):
   • Allows community members to view all active channel lobbies, filter by channel or participant, add or remove time slots directly from the browser, and export the full schedule to CSV.

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2. Sub-Second Synchronization with Supabase Realtime#

What makes the dashboard feel alive is its Supabase Realtime (postgres_changes) subscription pipeline:

typescriptCopy
const signupsSubscription = supabase
  .channel('signups_changes')
  .on('postgres_changes', { event: '*', schema: 'public', table: 'signups' }, () => {
    loadData(false); // Refresh lobby matrix without UI flicker
  })
  .subscribe();

When a player types /add 20 inside a Discord text channel, the Next.js web dashboard updates the 20:00 UTC participant badges in under 200ms over WebSockets—and when an organizer edits a slot on the web dashboard, the bot's state stays 100% consistent.