What inspired us
Every Reddit moderator faces the same invisible tax: before making any decision, they manually open the user's profile, scroll through history, check modmail for prior warnings, and cross-reference past bans. This takes 3–8 minutes per case. A subreddit with 50 daily reports loses 4–6 hours of mod time just gathering context — before a single decision is made. We built ModMind Pro to eliminate this entirely.
What it does
ModMind Pro is a moderation intelligence layer that works silently in the background. The moment a post or comment is submitted to a subreddit, ModMind Pro instantly fetches the author's account age, karma, and full violation history, then calculates a risk score from 0–100. By the time a mod opens the queue, everything is already there.
Three core systems running simultaneously:
1. Proactive Context Engine Triggers on PostSubmit and CommentSubmit — not after a mod action. Context is pre-built and cached in Redis before any mod opens the queue. Zero waiting. Zero manual lookup.
2. Risk Scoring Algorithm Every user gets a risk score calculated from:
- Account age (new accounts score higher)
- Karma (low or negative karma increases risk)
- Violation history (each prior removal adds 15 points)
- Maximum score: 100
$$\text{Risk} = \text{AgePenalty} + \text{KarmaPenalty} + (\text{Violations} \times 15)$$
Scores map to three levels: 🟢 LOW (0–34), 🟡 MEDIUM (35–69), 🔴 HIGH (70–100)
3. Pattern Detection & Coordination Alerts ModMind Pro learns from every decision. Three detectors run on every new submission:
- Repeat Offender Detector: flags users with 2+ violations in 7 days at up to 95% confidence
- Coordination Detector: flags when 3+ new accounts post within 60 minutes — the primary signal of brigading and spam campaigns
- Pattern Matcher: compares new users against 500 historical decisions. If 70%+ of similar profiles were removed, fires a pattern alert
How we built it
Built entirely on Reddit's Devvit platform using TypeScript. Four core files:
stateManager.ts— Redis schema, risk score formula, decision logger, violation tracker, alert systemcontextBuilder.ts— parallel Reddit API fetching with graceful fallbacks for deleted/suspended accountsdetector.ts— three independent detection algorithms running in parallel via Promise.allmain.ts— Devvit triggers wiring everything together
Every decision is logged permanently to Redis, building institutional memory that makes the system smarter over time. A subreddit that has been running ModMind Pro for 30 days has 500 historical decisions powering its pattern detection — something no new mod team has today.
Challenges we faced
The proactive trigger problem: Devvit's ModAction trigger fires after a mod acts, not before. We solved this by switching to PostSubmit and CommentSubmit triggers, so context is built the moment content arrives — before any human sees it.
The authorId problem: PostSubmit events return authorId, not authorName. We had to resolve the username via getUserById before building context, adding an extra API call to the pipeline.
Graceful degradation: The tool must work even when the Reddit API is slow or a user is deleted/suspended. Every API call is wrapped in try/catch with meaningful fallbacks — a deleted user gets a risk score of 60 (unknown = elevated risk), not a crash.
What we learned
The most valuable insight: moderation problems are fundamentally information problems. Mods don't make bad decisions because they lack judgment — they make inconsistent decisions because they have inconsistent information. ModMind Pro solves the information problem first, and everything else follows.
What's next
- AI-powered content classification using Anthropic API
- Cross-subreddit bad actor sharing between opted-in communities
- Mod team analytics dashboard showing queue health over time
- Weekly digest reports sent to mod teams automatically
Built With
- api
- devvit
- node.js
- redis
- typescript
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