ModMind — AI Mod Assistant for Reddit

Claude AI scores every post and comment in real time, surfacing a prioritized mod queue so volunteer moderators can focus on what needs human judgment — not drown in the noise.

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Inspiration

Moderating active subreddits is exhausting. A mid-size community with 100K subscribers receives hundreds of posts and thousands of comments daily. Volunteer mods burn out, toxic content lingers, and AutoModerator — while powerful — can't understand nuance. We built ModMind to give moderators an AI co-pilot that never sleeps.

What it does

ModMind is a native Devvit app that watches every new post and comment in your subreddit in real time. Each piece of content is scored by Claude Haiku on three axes: toxicity, spam, and rule violations. Items above configurable thresholds surface automatically in an AI-powered mod queue — a custom post component installed once and visible to all mods.

Moderators see a color-coded dashboard sorted by severity. Green = fine. Red = act now. Each card shows the AI's reasoning so mods can approve or remove with one click — and optionally auto-remove the clearest violations without any human in the loop.

How we built it

Built entirely on Reddit's Devvit platform using TypeScript. The app uses:

  • Devvit triggers (PostCreate, CommentCreate, AppInstall) to intercept content in real time
  • Anthropic Claude Haiku API for fast, cost-effective content scoring
  • Devvit Redis (kvStore) for queue persistence across sessions
  • Custom post components for the mod dashboard UI

Challenges we ran into

Devvit's strict JSX type system required careful serialization — useAsync hooks require JSONValue return types, so queue items are stringified and parsed back. We also had to account for the difference between PostV2 and UserV2 field names in event triggers.

Accomplishments that we're proud of

Zero false negatives on obvious toxicity in testing. The Redis queue design handles subreddits with thousands of daily posts without hitting storage limits. Claude's per-item reasoning strings give mods transparency — they trust the system because they can see why it flagged something.

What we learned

AI moderation works best as a prioritization tool, not a judge. Claude's reasoning strings help mods understand why something was flagged — building trust in the system rather than blind automation.

What's next for ModMind — AI Mod Assistant for Reddit

  • Learning mode: track mod decisions to fine-tune thresholds per subreddit
  • Multi-subreddit dashboard aggregation for mod teams
  • Appeal queue with AI-assisted review

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