native-android

native-android is a cursor rule for coding agents from kensaurus/cursor-kenji. It costs 0 tokens per session (613 once invoked), scanned A, original, MIT.

Coding rules for the native Android part of a React Native application, using Kotlin, Java, and Gradle. They cover native modules, asynchronous work, permissions, strings, and logging.

In plain words
What is it for?
They guide Android modules, Gradle changes, permission requests, background tasks, logging, and user-facing text.
Why use it?
They reduce Android-specific build and runtime mistakes, especially around permissions, package names, and communication with React Native.

Cursor rule

Install

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.

agentmods
npx agentmods add rules/kensaurus/cursor-kenji/native-android
Clone the repo
git clone --depth 1 https://github.com/kensaurus/cursor-kenji

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for native-android

README.md
[![agentmods](https://agentmods.dev/badge/rules/kensaurus/cursor-kenji/native-android.svg)](https://agentmods.dev/rules/kensaurus/cursor-kenji/native-android)
Your own site
<a href="https://agentmods.dev/rules/kensaurus/cursor-kenji/native-android"><img src="https://agentmods.dev/badge/rules/kensaurus/cursor-kenji/native-android.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 613 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What 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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00613
Opus 5 $0.00000 $0.00307
Sonnet 5 $0.00000 $0.00123
Haiku 4.5 $0.00000 $0.00061

Measured yesterday against content hash 1222eff59c70, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

native-android 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.

rules/native-rn-monorepo/native-android.mdc · 71 lines

How it starts

The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Native Android

Stack: Kotlin first, Java only when required by RN bridge or legacy code. Build: Gradle (Kotlin DSL where present). Min SDK / target SDK / compile SDK: read android/build.gradle — do NOT change without explicit instruction.

Adjust android/ to your repo's actual path (e.g. apps/mobile/android/).

Conventions

  • Package matches what's already declared in AndroidManifest.xml and build.gradle namespace.
  • Native modules for RN go under android/app/src/main/java/<package>/modules/.
  • Each native module = one *Module.kt (extends ReactContextBaseJavaModule) + one *Package.kt.
  • Register packages in MainApplication.kt (or via the new RN auto-linking if applicable).
  • Async: Coroutines + Flow. Never AsyncTask, never raw Thread, never RxJava unless the project already uses it.
  • Logging: android.util.Log with tag = class name. Wrap verbose logs in BuildConfig.DEBUG checks.
  • Strings: android/app/src/main/res/values/strings.xml. No hardcoded user-facing text.
  • Permissions: declare in AndroidManifest.xml AND request at runtime for dangerous permissions (camera, mic, location, storage on older API levels, notifications on API 33+).
  • Compose (if used): follow MaterialTheme tokens, no raw Color() literals in screen code.

Build verification (REQUIRED after any change)

Run /android-build or directly:

cd android && ./gradlew :app:assembleDebug --console=plain

Parse the output. If BUILD FAILED, fix the first error and re-run. Do not declare done without BUILD SUCCESSFUL.

If you hit OutOfMemoryError or metaspace errors, add to android/gradle.properties:

org.gradle.jvmargs=-Xmx4g -XX:MaxMetaspaceSize=512m
org.gradle.daemon=true
org.gradle.parallel=true
org.gradle.caching=true

What NOT to do

  • Do not add a new native module if the JS-side library can do it.
  • Do not edit MainActivity.kt ReactRootView wiring without explicit instruction.
  • Do not bump compileSdk, targetSdk, AGP, or Gradle wrapper versions casually — these cascade.
  • Do not commit local.properties, *.keystore, or google-services.json if it's gitignored.
  • Do not edit auto-generated files under android/app/build/.

Read the full file on GitHub · 71 lines

Changes

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.

  1. yesterday First seen · 71 lines · 0 tokens per session scan A 1222eff59c70

Subscribe to this mod's changes

native-android is a cursor rule published in the GitHub repository kensaurus/cursor-kenji (9 stars, last pushed 7d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 613 tokens. 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 2026-09-03.