Matrix Wiper

A Node.js script to automatically redact (delete) old messages from Matrix rooms and purge them from the server database.

Features

• Redacts messages older than a specified number of days
• Supports both regular and encrypted rooms
• Handles rate limiting gracefully with exponential backoff
• Dry-run mode by default for safety
• Purges old messages from server database after redaction
• Debug mode for troubleshooting

Installation

1. Clone this repository
2. Install dependencies:

   npm install

Configuration

Create a .env file with the following variables:

HOMESERVER_URL=https://your-matrix-server.com
ADMIN_TOKEN=your_admin_access_token
ROOM_ID=!your-room-id:server.com
REDACT_DAYS=7
PURGE_DAYS=30
LIMIT=100
RATE_LIMIT_DELAY=500

Configuration Options

• HOMESERVER_URL: Your Matrix homeserver URL
• ADMIN_TOKEN: Admin access token (or user token for someone in the room)
• ROOM_ID: The room ID to clean up (format: !localpart:domain.tld)
• REDACT_DAYS: Days after which messages should be redacted (default: 7)
• PURGE_DAYS: Days after which messages should be purged from database (default: 30)
• LIMIT: Number of messages to fetch per API call (default: 100)
• RATE_LIMIT_DELAY: Delay between requests in milliseconds (default: 500)

Usage

Dry Run (Safe Mode)

node wiper.js

Shows what would be deleted without actually doing it.

Actually Delete Messages

node wiper.js --commit

Override Redaction Days

node wiper.js --days 30 --commit

Debug Mode

node wiper.js --debug --commit

How It Works

1. Fetch Messages: Retrieves messages from the specified room using the Matrix Client API
2. Filter by Age: Identifies messages older than the specified number of days
3. Redact Messages: Sends redaction events to mark messages as deleted
4. Purge History: Uses Synapse admin API to permanently remove old messages from database

Rate Limiting

The script handles Matrix server rate limits automatically. To reduce rate limiting:

1. Increase RATE_LIMIT_DELAY in your .env file
2. Configure your Synapse server for higher admin redaction limits in homeserver.yaml:

rc_admin_redaction:
  per_second: 10000
  burst_count: 100000

Requirements

• Node.js
• Access to a Matrix homeserver with admin privileges
• Admin access token or user token for someone in the target room

Safety Features

• Dry-run mode by default (requires --commit to actually delete)
• Validates environment variables and configuration
• Validates room ID format
• Checks admin token format
• Handles network errors with retry logic

Supported Message Types

• Regular messages (m.room.message)
• Encrypted messages (m.room.encrypted)

Author

Developed by Alan P. Laudicina from Opreto

Contributing

Contributions are welcome! Open a PR.

License

MIT License