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 skills add alexei-led/cc-thingz --skill writing-java-kotlingit clone --depth 1 https://github.com/alexei-led/cc-thingzWrote 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.
[](https://agentmods.dev/skills/alexei-led/cc-thingz/writing-java-kotlin)<a href="https://agentmods.dev/skills/alexei-led/cc-thingz/writing-java-kotlin"><img src="https://agentmods.dev/badge/skills/alexei-led/cc-thingz/writing-java-kotlin.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00126 | $0.01024 |
| Opus 5 | $0.00063 | $0.00512 |
| Sonnet 5 | $0.00025 | $0.00205 |
| Haiku 4.5 | $0.00013 | $0.00102 |
Grade A, and why
writing-java-kotlin 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 7d ago.
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 — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Java and Kotlin Development
Use only for Java/Kotlin JVM code and JVM build files. Follow the project's JDK, Kotlin, Gradle/Maven, framework, test stack, formatter, static-analysis config, and local conventions.
Read First
Read principles.md before writing, changing, or reviewing Java/Kotlin code. Read conditional references only when the change touches that area.
Conditional References
- patterns.md — package/module layout, Spring/Ktor/service boundaries, nullability, concurrency, persistence, and build seams.
- testing.md — adding or reshaping JUnit, Kotest, Mockito/MockK, Spring, or Gradle/Maven tests; keep the local loop fast.
- linting.md — Gradle/Maven toolchains, formatters, ktlint, detekt, Spotless, and slow-check policy.
- cli.md — writing or changing JVM CLIs.
Project Baseline
- Inspect
gradle/wrapper/gradle-wrapper.properties,settings.gradle*,build.gradle*,pom.xml,.mvn/,gradle.properties, CI, and nearby code before using version-specific Java, Kotlin, or plugin behavior. - Prefer the project wrapper:
./gradlewbefore globalgradle;./mvnwbefore globalmvn. - Use the configured Java toolchain and Kotlin
jvmToolchain. Do not assume the shell's newest JDK is the compile target. - Prefer the JDK/Kotlin stdlib and existing dependencies before adding a library.
- Keep domain code free of framework, persistence, HTTP, and DI types unless the project already chose that coupling.
Version-Gated APIs
- Java 21+: records, sealed types, pattern matching, switch expressions, and virtual threads are available when the project toolchain allows them.
- Java 25+: treat new platform APIs as available only when Gradle/Maven toolchains and CI target 25 or newer.
- Preview features require explicit user or project approval and a visible compiler/test flag.
- Kotlin: follow the configured Kotlin language/API version. Do not use a Kotlin 2.x feature unless the build already enables it.
What ships with it
6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 7d ago First seen · 76 lines · 126 tokens per session scan A 40913e807313
writing-java-kotlin is a skill published in the GitHub repository alexei-led/cc-thingz (35 stars, last pushed 1mo ago), licensed MIT. It adds 126 tokens to every session and 1,024 once invoked, about $0.0006 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 2026-08-30.
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