diff --git a/services/modpack-version-checker/CLAUDE.md b/services/modpack-version-checker/CLAUDE.md
new file mode 100644
index 0000000..f0f9f98
--- /dev/null
+++ b/services/modpack-version-checker/CLAUDE.md
@@ -0,0 +1,80 @@
+# ModpackChecker — Development Guide
+
+## What This Is
+A commercial product for the Minecraft server hosting community. Two components:
+
+### 1. Python CLI Tool (`src/modpack_checker/`)
+- pip-installable utility that monitors CurseForge modpack versions
+- Discord webhook notifications when updates drop
+- SQLite database for version history and scheduling
+- Target marketplace: BuiltByBit (paid product)
+
+### 2. Pterodactyl Blueprint Extension (`blueprint-extension/`)
+- PHP/Laravel backend + React/TSX frontend
+- Adds update badges to Pterodactyl Panel dashboard
+- Orange dot = update available, Green dot = up to date
+- Console widget for manual version checks
+- Target marketplace: BuiltByBit (paid product)
+
+## Dev Panel Environment
+- Python 3.12, PHP 8.3, Node.js 24
+- Blueprint beta-2026-01 installed
+- Pterodactyl Panel running at this server
+- Phase 5 backup at `/root/modpackchecker_backup/`
+
+## Key Files
+- `src/modpack_checker/cli.py` — CLI entry point
+- `src/modpack_checker/curseforge.py` — CurseForge API client
+- `src/modpack_checker/notifier.py` — Discord webhook sender
+- `src/modpack_checker/database.py` — SQLite persistence
+- `blueprint-extension/conf.yml` — Blueprint manifest
+- `blueprint-extension/build.sh` — Build script for .blueprint package
+- `blueprint-extension/views/dashboard/UpdateBadge.tsx` — Dashboard badge component
+- `blueprint-extension/views/server/wrapper.tsx` — Server console widget
+- `blueprint-extension/app/Services/ModpackApiService.php` — Backend API service
+- `blueprint-extension/app/Console/Commands/CheckModpackUpdates.php` — Artisan command
+
+## Blueprint Build & Install
+```bash
+cd blueprint-extension
+bash build.sh                    # Creates .blueprint package
+blueprint -install modpackchecker  # Installs on this Panel
+```
+
+## Python Build & Test
+```bash
+pip install -e .                 # Install in dev mode
+modpack-checker --help           # Verify CLI works
+pytest tests/                    # Run test suite
+```
+
+## Git
+- Repo: firefrost-services (main branch)
+- Path: services/modpack-version-checker/
+- Push requires Gitea token: already in repo clone URL
+
+## Commercial License
+This is a PAID product. Do not include any open-source license headers.
+All code is: "Commercial License - Unauthorized redistribution prohibited."
+
+## Accessibility
+Michael has hand surgery limitations. Small code blocks (8-10 lines).
+One question at a time. Complete files over patches.
+
+## PRICING — LOCKED (DO NOT CHANGE)
+
+### Standard Tier: $14.99
+- CurseForge & Modrinth support
+- Smart auto-detection
+- Dashboard status badges
+- Manual UI re-scan button
+- Standard support (48h SLA)
+
+### Professional Tier: $24.99
+- Everything in Standard PLUS:
+- FTB support
+- Background auto-cron checks (every 6 hours)
+- Discord webhook alerts
+- Priority support (24h SLA)
+
+Launch at FULL PRICE. No discounts. No price drift.