Sountinel

A Devvit app that validates links posted to r/Drumkits. Checks that shared files are publicly accessible and contain audio content.

What It Does

When a new post is submitted to r/Drumkits:

1. Identifies the file host (Google Drive, Dropbox, or MediaFire)
2. Validates accessibility — is the link public? (no login/permission required)
3. Checks for audio content — does the link point to audio files or archives?
4. Acts on the result:
   • Pass: Post stays up, nothing happens
   • Fail: Post is removed with a sticky comment explaining why and how to fix it
   • Error/Uncertain: Post is reported to the mod queue for human review

Posts using unsupported file hosts are handled by AutoModerator (provider allowlist), not this app.

Supported Providers

Provider	Validation Method	Folders
Google Drive	Drive API v3 (API key)	API traversal, 1 level deep
Dropbox	HTTP scraping	Pass if accessible (contents not inspectable)
MediaFire	HTTP scraping	Pass if accessible (contents not inspectable)

Quick Start

Prerequisites

• Devvit CLI installed
• A Google Drive API key (create one — takes 5 minutes, no OAuth needed)
• Moderator access to a test subreddit

Deploy

# Upload to Devvit
npm run deploy

Configure the API Key

# Set the Google Drive API key (app-scoped secret)
npx devvit settings set google_drive_api_key --app sountinel

Install to a Subreddit

# Install to your test subreddit
npx devvit install <subreddit_name>

Test

1. Create a test post with a Google Drive / Dropbox / MediaFire link
2. Check the logs:

npx devvit logs <subreddit_name>

Project Structure

sountinel/
  devvit.yaml              # HTTP domain allowlist for all 3 providers
  src/
    main.ts                # PostSubmit trigger → validate → remove/report
    types.ts               # ValidationResult, Provider, FailureType
    config.ts              # Audio/archive extensions, helpers
    comments.ts            # Removal comment templates + flair text
    providers/
      index.ts             # Provider detection + dispatch
      googleDrive.ts       # Google Drive API v3 validation
      dropbox.ts           # Dropbox HTTP validation
      mediafire.ts         # MediaFire HTTP validation
    __tests__/
      config.test.ts
      comments.test.ts
      providers/
        index.test.ts

How Validation Works

Google Drive

• Extracts file/folder ID from URL
• Calls Drive API v3 for metadata (name, mimeType, size)
• HTTP 403 → private link, HTTP 404 → dead link
• Single files: checks extension against audio formats
• ZIP/RAR/7z: assumed to contain audio
• Folders: lists root files, then 1 level of subfolders. No audio after traversal → mod queue (not auto-remove)

Dropbox & MediaFire

• Fetches the shared link page via HTTP GET
• Parses HTML for error states (deleted, private, password-protected)
• Checks filename from URL path or og:title meta tag
• Folders: pass if accessible — file listings are JS-rendered (protobuf-based) and can't be reliably parsed without a protobuf library

Moderation Actions

Result	Action	Flair
Private/login required	Remove + comment	Needs Fix: Private Link
404 / dead link	Remove + comment	Removed: Dead Link
No audio (single file)	Remove + comment	Removed: No Audio
No audio (Google Drive folder, after traversal)	Report to mod queue	Needs Review
API timeout / error	Report to mod queue	Needs Review

Principle: When in doubt, don't remove. Send to mod queue.

Development

# Type check
npm run type-check

# Run tests
npm test

# Playtest locally
npm run dev

# Deploy
npm run deploy

Learn More

• Devvit Documentation
• Developer Portal
• Google Drive API v3

License

BSD-3-Clause