lethe

Auto-deletes Discord messages older than a configurable threshold from one or more channels.

Environment Variables

Variable	Required	Default	Description
DISCORD_TOKEN	yes	—	Bot token
CHANNEL_IDS	yes	—	Comma-separated channel IDs
MAX_AGE	yes	—	Message age threshold (e.g. 720h, 168h)
SCHEDULE	no	0 */6 * * *	Cron expression(s), semicolon-separated for multiple (e.g. 0 3 * * *;0 15 * * *)
TZ	no	UTC	Timezone for schedules (e.g. Europe/Berlin)

Quick Start

Docker Compose

cp .env.example .env
# edit .env with your values
docker compose up -d

Without Docker

go build -o lethe .
DISCORD_TOKEN=... CHANNEL_IDS=123,456 MAX_AGE=720h ./lethe

Discord Bot Setup

1. Create an application at https://discord.com/developers/applications
2. Go to Bot → copy the token → set as DISCORD_TOKEN
3. Go to OAuth2 → URL Generator → select scope bot
4. Select permissions: Manage Messages, Read Message History
5. Open the generated URL to invite the bot to your server

How It Works

• On start, immediately deletes all messages older than MAX_AGE
• Then repeats every INTERVAL
• Messages < 14 days old are bulk-deleted (up to 100 per API call)
• Messages >= 14 days old are deleted individually (Discord API limitation)
• Supports multiple channels via comma-separated CHANNEL_IDS
• Shows as online in Discord with "Watching cleanup" status

License

Unlicense