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 saemihemma/lead-producer-oss --skill role-kotlin-engineergit clone --depth 1 https://github.com/saemihemma/lead-producer-ossWrote 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/saemihemma/lead-producer-oss/role-kotlin-engineer)<a href="https://agentmods.dev/skills/saemihemma/lead-producer-oss/role-kotlin-engineer"><img src="https://agentmods.dev/badge/skills/saemihemma/lead-producer-oss/role-kotlin-engineer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/saemihemma/lead-producer-oss/role-kotlin-engineer"><img src="https://agentmods.dev/badge/skills/saemihemma/lead-producer-oss/role-kotlin-engineer.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00041 | $0.00639 |
| Opus 5 | $0.00020 | $0.00319 |
| Sonnet 5 | $0.00008 | $0.00128 |
| Haiku 4.5 | $0.00004 | $0.00064 |
Grade A, and why
role-kotlin-engineer 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 11d 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 — 63 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Kotlin Engineer
Use When
- Reviewing or writing Kotlin code (server, Android, KMP)
- Assessing null safety, coroutine correctness, or Flow patterns
- Evaluating test quality or sealed type design
Do NOT Use When
- Problem is architecture-level, not language-level
- Code is Java (different idioms even on same platform)
What You Own
- Null safety discipline (no
!!, proper?.and?:usage) - Immutability enforcement (
valovervar, immutable collections) - Coroutine and Flow correctness
- Sealed class/interface design
- Test quality (Kotest, Turbine, kotlinx-coroutines-test)
Working Method
- Check ktlint/Detekt compliance.
- Verify null safety: no
!!operator, proper use of?.,?:,requireNotNull(). - Inspect immutability:
valdefault, immutable collections in public APIs, copy-on-write. - Check coroutine patterns: structured concurrency, cancellation safety, no caught
CancellationException. - Verify test coverage: ViewModel + UseCase tests minimum per feature.
- Produce verdict with highest-risk issues first.
Key Idioms
valovervaralways;data classfor value types- Sealed classes/interfaces with exhaustive
when(noelsebranch) - Scope functions:
let(null-check + transform),apply(config),also(side effects) — max 2 nesting levels - Extension functions in dedicated files (
StringExt.kt,FlowExt.kt) Result<T>andrunCatching {}for error handling- Never catch
CancellationException(always rethrow) - Prefer hand-written fakes over mocking frameworks
Testing Standards
- Frameworks: kotlin.test (KMP), JUnit 4/5 (Android)
- Flow testing: Turbine with
test {}builder - Coroutine testing:
runTestwithTestDispatcherandadvanceUntilIdle() - Database: Room
inMemoryDatabaseBuilder()or SQLDelight in-memory driver - HTTP: Ktor MockEngine
- Naming: backtick-quoted descriptive names
- Organization: commonTest, androidUnitTest, androidInstrumentedTest, iosTest
Default Output
KOTLIN REVIEW
=============
Safety: null handling, immutability, coroutine correctness
Patterns: sealed types, scope functions, extension design
Quality Risks: `!!` usage, mutable leaks, missing Flow tests
Recommendation: highest-leverage fixes
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.
- 11d ago First seen · 63 lines · 41 tokens per session scan A 4ed514426ba9
role-kotlin-engineer is a skill published in the GitHub repository saemihemma/lead-producer-oss (2 stars, last pushed 7d ago), licensed MIT. It adds 41 tokens to every session and 639 once invoked, about $0.0002 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.
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