Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add rules/kaelsensei/magicaibuilder/technical-stackgit clone --depth 1 https://github.com/KaelSensei/MagicAIBuilderWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.01259 | $0.01259 |
| Opus 5 | $0.00629 | $0.00629 |
| Sonnet 5 | $0.00252 | $0.00252 |
| Haiku 4.5 | $0.00126 | $0.00126 |
Grade A, and why
technical-stack scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 131 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Technical Stack Rules
These rules guide the AI assistant when generating or modifying code in MagicTheOfflining, a React Native offline MTG deck viewer.
JavaScript / TypeScript
- Use modern ES modules (
import/export) rather than CommonJS (require). - Prefer TypeScript; avoid
anyand use clear types/interfaces. - Follow consistent formatting and typing patterns across all
.tsand.tsxfiles. - Keep logic simple and explicit; avoid magic abstractions.
React Native
- Target Android first; iOS support is planned for future releases.
- Components should prioritize:
- Readability and speed over fancy animations.
- Simple layouts and easy‑to‑scan typography.
- Use functional components with hooks; avoid legacy class components.
- Keep screens small and focused; share UI via small, well‑named components.
Android Development
Build Configuration
- Gradle Setup: Use
android/app/build.gradlefor app-level configuration - Signing: Release builds use
keystore.properties(never commit this file) - ProGuard/R8: Enabled for release builds to minimize APK size
- Hermes: Enabled by default for better performance
- New Architecture: Currently disabled (
IS_NEW_ARCHITECTURE_ENABLED = false)
Build Commands
- Debug APK:
cd android && ./gradlew :app:assembleDebug - Release APK:
cd android && ./gradlew :app:assembleRelease - Release AAB (for Play Store):
cd android && ./gradlew :app:bundleRelease - Clean build:
cd android && ./gradlew clean
Android-Specific Considerations
- Min SDK: Check
rootProject.ext.minSdkVersioninandroid/build.gradle - Target SDK: Must match latest Android requirements for Play Store
- Permissions: Declare in
android/app/src/main/AndroidManifest.xml - File Storage: Use
react-native-fsfor local file access (images, SQLite) - SQLite: Use
react-native-sqlite-storage(Android-compatible) - Image Caching: Store in app's internal storage for offline access
- Network: Only allow Moxfield and Scryfall domains; handle offline gracefully
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 131 lines · 1,259 tokens per session scan A 00e6c00b62da
technical-stack is a cursor rule published in the GitHub repository KaelSensei/MagicAIBuilder (2 stars, last pushed 2d ago), licensed MIT. It adds 1,259 tokens to every session, about $0.0063 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other cursor rules, from other repositories
server-actions
Server Action, service and tenancy contract.
project
Product, stack and layer contract. Always applies.
ui-design-system
UI, design tokens and mobile-first rules.
performance
Navigation, caching and PWA contract.
prisma-schema
Prisma schema and migration conventions.
tdd-domain
TDD contract for business logic.