Mod Thread: Case Rooms for Reddit Moderators

Overview

Mod Thread is a Reddit Devvit moderation app built for the Reddit Mod Tools and Migrated Apps Hackathon in the Best New Mod Tool category.

It helps moderators handle heated local or city subreddit threads by turning a messy comment branch into a shared case room. The workflow combines branch weather, an evidence trail, a context-pin draft, and reusable precedent records in one moderator-focused surface.

Problem

Moderators often lose time rereading long comment branches, reconstructing what another moderator already checked, and explaining why a moderation decision was made.

This gets worse in local or civic threads where a rumor spreads quickly, multiple users ask the same question, and several moderators may touch the same branch at different times.

Solution

Mod Thread gives the team an operational case room for one thread. Moderators can:

• review deterministic Thread Weather for the active branch
• see reason codes behind the state
• preserve context in a shared Mod Trail
• draft a public context pin for verified information
• save an internal precedent card for future similar incidents

The app intentionally avoids opaque AI moderation scoring. Its goal is explainable triage and team handoff, not automated enforcement.

Product Capabilities

Thread Weather

Thread Weather summarizes branch state using deterministic signals and reason codes. Supported states include calm, warming, flame_pocket, report_spike, missing_context, helpful_correction, and cooldown_needed.

Example reason codes include fast_reply_branch, missing_source_context, multiple_reports, repeated_question, helpful_correction_present, and mod_action_seen.

Mod Trail

Each hotspot has a shared moderator-authored trail. Entries can capture origin markers, evidence, source requests, ownership handoffs, context-pin drafts, resolutions, and saved precedents.

Context Pin Draft

Moderators can maintain a public-facing draft for verified context. The MVP stores the draft inside the case room so the team can align before public action.

Precedent Cards

Precedent cards save reusable internal moderation memory: rule tag, context summary, decision, rationale, and future guidance.

Architecture

Moderator
  -> Devvit Custom Post
  -> React Case Room UI
  -> Hono API routes
  -> ModThreadService
  -> Weather Engine
  -> Repository
  -> Devvit Redis

The codebase separates shared domain types, deterministic weather logic, repository interfaces, Redis persistence, service-layer use cases, seeded demo data, API routes, and the custom-post UI.

Verification

The project includes coverage for domain helpers, weather states, the deterministic weather engine, in-memory repository behavior, fake Redis repository behavior, service-layer retry safety, seeded demo idempotence, Hono API routes, and Case Room UI rendering.

The documented verification flow runs type-checking, Vitest, linting, and build checks from the mod-thread app directory.

What This Shows

Mod Thread demonstrates practical product engineering for a real moderation workflow: a narrow user, a concrete job, deterministic logic where trust matters, and a UI designed around repeated operational decisions rather than a generic dashboard.