ModScout — New Member Onboarding for Reddit Mods

Inspiration

Every subreddit is silently hemorrhaging good users in their first 48 hours. A newcomer joins, makes a post that breaks a rule they didn't know about, gets a cold removal notice, feels unwelcome, and leaves forever. The mod team wasted 5 minutes removing it. The community lost a potential top contributor. This happens hundreds of times a day on large subreddits — and no tool existed to fix it.

We kept seeing the same pattern: 70–80% of removed posts come from accounts under 30 days old, always for the same 2–3 rule violations. Mods were doing the same reactive cleanup every single day with no way to break the cycle. ModScout was built to fix the problem at the source instead of cleaning up after it.

What it does

ModScout is a three-part onboarding and coaching system for Reddit moderators:

1. Smart Welcome DM The moment a new user joins, ModScout sends them a personalised DM listing the top 3 rules most commonly broken by newcomers — configurable by mods per subreddit. Friendly tone, not a wall of legalese.

2. First-Post Checklist Comment When a new member submits their first post, ModScout automatically posts a distinguished mod comment with a quick rule checklist. This surfaces the rules exactly when the user needs them — right before their post goes live — preventing the mistake before it happens.

3. Removal Coaching DM If a new member's first post is removed, ModScout immediately sends them a personalised DM explaining exactly what the removal reason was, which rules to check, and a clear call-to-action to repost correctly. No more users reposting the same broken thing three times in frustration.

4. Live Mod Dashboard A pinnable custom post showing real-time stats: total new members tracked, first-post success rate, removal rate, repost-after-coaching rate, and a list of members who haven't posted yet so mods can proactively reach out.

5. Full Mod Configuration Mods control everything from a simple settings form: toggle each feature on/off, set the 3 most-broken rules used in all messages, and add a custom welcome suffix.

How we built it

ModScout is built entirely on Devvit — Reddit's native developer platform — using TypeScript.

• Triggers: PostSubmit fires the checklist comment on first posts. PostDelete fires the coaching DM when a removal happens. ModAction fires the welcome DM on new subscriptions.
• Storage: Devvit KVStore stores per-member records, subreddit config, and rolling stats — all scoped per subreddit install.
• Scheduler: A daily cleanup job prunes stale pending-poster records older than 14 days, keeping storage lean.
• UI: Built with Devvit Blocks — Reddit's native UI framework — for the dashboard custom post and the settings form. No external dependencies.
• Messaging: Reddit's private message API handles all DMs, with graceful error handling for users who have DMs disabled.

Challenges we ran into

The biggest challenge was working with Devvit's trigger event naming — some events like PostDelete vs PostRemove aren't obvious from the docs and required testing to confirm. We also had to design the member tracking logic carefully: not every new user triggers a subscription event reliably, so we added a fallback that detects new accounts (under 30 days old) directly on their first post submission.

Handling edge cases gracefully — deleted users, DMs disabled, duplicate events — required defensive coding throughout to ensure no trigger ever crashes silently and corrupts the KVStore state.

Accomplishments that we're proud of

• The entire new-member lifecycle — join → welcome → first post → coaching → repost — is handled automatically with zero mod intervention required.
• The dashboard gives mods visibility they've never had before: what percentage of new members post successfully, and which ones need a nudge.
• The app is genuinely install-ready: one click from the App Directory, configure 3 rules, done. No setup complexity.
• Every message is warm and human — not a cold automod wall of text. New users who receive coaching feel helped, not punished.

What we learned

Moderation tools succeed or fail on trust. Mods won't install something they can't understand or control. We learned to make every feature a toggle, every message configurable, and every action logged. The mod dashboard exists specifically because mods need to see that the tool is working — invisible automation makes people nervous.

We also learned that the most impactful mod tools aren't the ones that handle the worst-case scenarios (spam, trolls, brigades) — those are already handled. The gap is in the mid

Built With

• devvit
• devvit-kvstore
• devvit-scheduler
• reddit
• typescript