ModCheck — Stardew Valley Mod Conflict Scanner That Finds the Crash Before You Do

Q: Who can build ModCheck — Stardew Valley Mod Conflict Scanner That Finds the Crash Before You Do?

This is a beginner level project. Stardew Valley PC players using SMAPI mod loader — estimated 500,000 active SMAPI users based on SMAPI download stats on Nexus Mods.

Q: How does ModCheck — Stardew Valley Mod Conflict Scanner That Finds the Crash Before You Do make money?

Freemium, $4/month Pro. Free: unlimited log paste and conflict report. Pro $4/month: auto mod update checker via Nexus Mods API and saved mod profile history.

Every Stardew Valley modder has lost a 200-hour farm save to a silent mod conflict that SMAPI logs in a wall of red text nobody can read. ModCheck parses your SMAPI log, maps dependency conflicts, and tells you exactly which mod is the problem in plain English.

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Difficulty

beginner

What is it?

Stardew Valley has over 10,000 mods on Nexus Mods and a SMAPI ecosystem where dependency conflicts are invisible until your game crashes on load or corrupts a save. The SMAPI log file is the only diagnostic tool and it is a raw text wall that requires 20 minutes of forum archaeology to decode. ModCheck takes a SMAPI log paste, parses every dependency warning, version mismatch, and missing manifest entry, and outputs a structured conflict report with plain-English explanations and direct Nexus Mods links to the correct mod versions. A shareable report URL lets players post their conflict report in r/SMAPI instead of pasting 300 lines of raw log. Target audience: the 500,000 active SMAPI mod users on PC. Buildable in 3 days with a Next.js frontend, a Node.js SMAPI log parser, and Claude for natural language conflict explanations. Monetized via a $4/month Pro tier that adds automatic mod update checking against the Nexus Mods API.

Why now?

Stardew Valley's 1.6 update in 2024 broke thousands of mods and forced a mass SMAPI migration, creating a permanent wave of confused players in r/SMAPI who have no automated diagnostic tool — the pain is fresh and the community is enormous.

▸Paste or upload SMAPI log.txt and receive a structured conflict report in under 5 seconds.
▸Plain-English explanation of each conflict with the specific mod name and version mismatch highlighted.
▸Direct Nexus Mods links to the correct version of each conflicting mod.
▸Shareable report URL for posting in r/SMAPI or CurseForge forums without pasting raw logs.

Target Audience

Stardew Valley PC players using SMAPI mod loader — estimated 500,000 active SMAPI users based on SMAPI download stats on Nexus Mods.

Example Use Case

A player with 47 mods installed pastes their SMAPI crash log, sees a conflict report showing that Stardew Valley Expanded v1.14 requires a newer Content Patcher version than installed, clicks the direct Nexus link, updates one mod, and their farm loads in under 3 minutes.

User Stories

▸As a Stardew Valley player with 40+ mods, I want to paste my SMAPI crash log and see which mod is causing the conflict, so that I can fix my game without reading 300 lines of raw error text.
▸As a modder helping others in r/SMAPI, I want to share a formatted conflict report URL, so that I can diagnose someone's log without asking them to paste the entire raw file in a comment.
▸As a Pro subscriber, I want to see which of my installed mods have newer versions on Nexus, so that I can update everything before a crash happens.

Done When

✓Log Parsing: done when user pastes a SMAPI log with at least one conflict and sees a ConflictCard with the correct mod name and conflict type within 5 seconds.
✓Plain-English Explanation: done when each ConflictCard shows a 1-2 sentence human-readable explanation of why the conflict occurs, not raw log text.
✓Nexus Link: done when each ConflictCard displays a working link that opens the correct Nexus Mods page for the conflicting mod.
✓Shareable URL: done when user clicks Share and the generated URL opens the same conflict report in a private browser without any login prompt.

Is it worth building?

$4/month x 500 Pro users = $2,000 MRR. Realistic at month 4 given 500,000 addressable users. Free tier drives word of mouth in r/SMAPI.

Unit Economics

CAC: $0 via organic r/SMAPI posts. LTV: $48 (12 months at $4/month). Payback: immediate. Gross margin: ~95%.

Business Model

Freemium, $4/month Pro

Monetization Path

Free: unlimited log paste and conflict report. Pro $4/month: auto mod update checker via Nexus Mods API and saved mod profile history.

Revenue Timeline

First dollar: week 2 via first Pro upgrade. $500 MRR: month 2. $2k MRR: month 5.

Estimated Monthly Cost

Claude Haiku API: $5, Vercel: $20, Supabase: $25, Nexus Mods API: free tier. Total: ~$50/month at launch.

Profit Potential

Side income viable at $2k MRR. Not full-time scale but high virality potential in the Stardew modding community.

Scalability

Low-Medium — V2 adds mod profile export and a community conflict database. Monetization ceiling is consumer-tier $4-8/month.

Success Metrics

Week 1: 500 free log pastes. Month 1: 100 Pro upgrades. Month 3: 400 Pro subscribers.

Launch & Validation Plan

Post in r/SMAPI and r/StardewValley with a working demo link before building the Pro tier.

Customer Acquisition Strategy

First users: post a worked example in r/SMAPI showing a real conflict resolved using the tool — no self-promotion, just a helpful reply to an active troubleshooting thread. Ongoing: r/StardewValley, Stardew Valley Discord, Nexus Mods mod page comments.

What's the competition?

Competition Level

Low

What's the roadmap?

Feature Roadmap

V1 (launch): log paste, conflict report, plain-English explanations, Nexus links, shareable URL. V2 (month 2-3): Pro auto update checker, saved report history. V3 (month 4+): community conflict database, mod profile export.

Milestone Plan

Phase 1 (Day 1-2): parser and conflict card UI done when real SMAPI log produces correct conflict list. Phase 2 (Day 3): shareable URL and deploy done when live link works from r/SMAPI post. Phase 3 (Month 1): 100 Pro subscribers, update checker shipped.

How do you build it?

Tech Stack

Next.js, Node.js SMAPI log parser, Claude API (Haiku for cost), Nexus Mods API, Supabase — build with Cursor for parser logic, v0 for the conflict report UI

Suggested Frameworks

Next.js App Router, Anthropic Node SDK, Nexus Mods REST API

Time to Ship

3 days

Required Skills

Text parsing with regex, Next.js file upload, Nexus Mods API, Claude Haiku prompt.

Resources

SMAPI log format docs on GitHub, Nexus Mods API docs, Next.js file upload guide.

MVP Scope

app/page.tsx (log paste UI + report display), app/api/parse/route.ts (SMAPI log parser + Claude explanation), app/api/share/route.ts (generate shareable report URL), lib/smapiParser.ts (regex parser for conflicts and warnings), lib/nexus.ts (Nexus Mods API version lookup), lib/db/schema.ts (reports table), components/ConflictCard.tsx (per-conflict display), .env.example

Core User Journey

Paste SMAPI log -> click Analyze -> read conflict report -> click Nexus fix link -> update mod -> game loads.

Architecture Pattern

User pastes SMAPI log -> Next.js API parses with regex -> extracts conflict entries -> Claude Haiku generates plain-English per-conflict explanation -> Nexus Mods API fetches correct version links -> structured report stored in Supabase -> shareable URL returned to user.

Data Model

Report has one raw_log, many ConflictEntries. ConflictEntry has mod_name, conflict_type, explanation, nexus_url. Report has one share_token.

Integration Points

Claude Haiku for plain-English conflict explanations, Nexus Mods REST API for version lookups, Supabase for report storage and shareable URLs, Vercel for hosting.

V1 Scope Boundaries

V1 excludes automatic mod installation, mod profile management, support for non-SMAPI mods, mobile app, and team features.

Success Definition

A stranger with a crashing Stardew installation pastes their SMAPI log, reads the conflict report, follows the fix links, and their game loads — without ever visiting a forum.

Challenges

Nexus Mods API requires a personal API key which adds friction for Pro users. SMAPI log format changes with major SMAPI releases — parser must be updated on each SMAPI release. Consumer pricing at $4/month means revenue ceiling is low — viral sharing in r/SMAPI and r/StardewValley is the only distribution that makes this viable.

Avoid These Pitfalls

Do not try to auto-install or auto-update mods — Nexus Mods terms prohibit automated mod file downloads without user action. Do not assume SMAPI log format is stable — pin parser to a known SMAPI version range and add a version detection check. Do not charge more than $4-8/month for a consumer gaming tool — the audience will balk at anything that feels like a SaaS subscription.

Security Requirements

No auth required for free tier, Supabase Auth magic link for Pro, RLS on saved reports, rate limit 30 parses per hour per IP, no mod file storage.

Infrastructure Plan

Vercel for Next.js, Supabase for report storage, no file storage needed (log text only), GitHub Actions for CI, Sentry for errors.

Performance Targets

Full log parse and Claude response under 5s, page load under 1.5s, 500 DAU at peak, CDN for static assets.

Go-Live Checklist

☐Security audit complete.
☐Payment flow tested end-to-end.
☐Sentry error tracking live.
☐Monitoring dashboard configured.
☐Custom domain with SSL active.
☐Privacy policy and terms published.
☐10+ beta players signed off.
☐Rollback plan documented.
☐r/SMAPI and r/StardewValley launch posts drafted.

First Run Experience

On first run: a pre-loaded demo SMAPI log with 3 real conflicts is already in the paste box. User can immediately click Analyze and see three ConflictCards with explanations and Nexus links without pasting anything. No account or API key required to try the demo.

How to build it, step by step

1. Document the SMAPI log schema by downloading 5 real crash logs from r/SMAPI and mapping every error and warning pattern. 2. Build lib/smapiParser.ts with regex patterns that extract mod name, version, dependency name, and conflict type from each log line. 3. Scaffold Next.js app with a single-page paste textarea and Analyze button. 4. Build app/api/parse/route.ts that runs smapiParser, calls Claude Haiku with a structured prompt per conflict entry, and returns a conflict array. 5. Build ConflictCard.tsx displaying mod name, conflict explanation, severity badge, and Nexus link. 6. Integrate Nexus Mods API in lib/nexus.ts to fetch the latest stable version URL for each conflicting mod by mod ID. 7. Build app/api/share/route.ts that saves the report JSON to Supabase with a random share token and returns a shareable URL. 8. Add Stripe $4/month Pro checkout gating the saved report history and auto-update checker features. 9. Build a Pro-only mod update checker that compares installed versions from the log against current Nexus Mods versions and flags outdated mods. 10. Verify: paste a real SMAPI crash log, confirm conflict cards appear with correct mod names and Nexus links, click the shareable URL from a private window, and confirm the report loads without login.

Generated

May 29, 2026

Model

claude-sonnet-4-6

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Disclaimer: Ideas on this site are AI-generated and may contain inaccuracies. Revenue estimates, market demand figures, and financial projections are illustrative assumptions only — not financial advice. Do your own research before making any business or investment decisions. Technology availability, pricing, and market conditions change rapidly; always verify details independently.