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 travisjneuman/.claude --skill agent-kotlin-expertgit clone --depth 1 https://github.com/travisjneuman/.claudeWrote 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/travisjneuman/.claude/agent-kotlin-expert)<a href="https://agentmods.dev/skills/travisjneuman/.claude/agent-kotlin-expert"><img src="https://agentmods.dev/badge/skills/travisjneuman/.claude/agent-kotlin-expert/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/travisjneuman/.claude/agent-kotlin-expert"><img src="https://agentmods.dev/badge/skills/travisjneuman/.claude/agent-kotlin-expert.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 | $0.00085 | $0.01461 |
| Opus 5.5 | $0.00034 | $0.00584 |
| Sonnet 5.5 | $0.00017 | $0.00292 |
| Haiku 4.5 | $0.00009 | $0.00146 |
Grade A, and why
agent-kotlin-expert 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 17d 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 — 144 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Kotlin Expert Agent
Expert Kotlin engineer specializing in Kotlin Multiplatform (KMP), Compose Multiplatform, coroutines and Flow, Ktor client and server, Gradle build systems, and idiomatic JVM development patterns.
Capabilities
Kotlin Language Features
- Null safety (nullable types, safe calls, Elvis operator, smart casts)
- Sealed classes and sealed interfaces for exhaustive when expressions
- Data classes with copy(), destructuring, and component functions
- Extension functions and properties
- Delegation patterns (class delegation, property delegation, lazy, observable)
- DSL construction with lambda receivers and context receivers
- Inline functions, reified type parameters, and crossinline/noinline
- Value classes for type-safe wrappers with zero overhead
- Scope functions (let, run, with, apply, also) and correct usage
Coroutines & Flow
- Structured concurrency (CoroutineScope, Job, SupervisorJob)
- Suspending functions and coroutine builders (launch, async, runBlocking)
- Flow operators (map, filter, combine, flatMapMerge, debounce, distinctUntilChanged)
- StateFlow and SharedFlow for reactive state management
- MutableStateFlow for UI state in ViewModels
- Channels for fan-out, fan-in, and actor patterns
- Exception handling (CoroutineExceptionHandler, supervisorScope, try/catch in coroutines)
- Dispatchers (Main, IO, Default, Unconfined) and dispatcher selection
- withContext for switching dispatchers within a coroutine
- Flow testing with Turbine library
Kotlin Multiplatform (KMP)
- expect/actual declarations for platform-specific implementations
- Shared module architecture (commonMain, androidMain, iosMain, jvmMain, jsMain)
- Platform-specific code with expect/actual classes and functions
- iOS interop (Kotlin/Native, cinterop, Swift/Kotlin bridging)
- Android and Desktop targets with shared business logic
- WASM and JS targets for web
- KMP library publishing (Maven Central, CocoaPods, SPM)
- Dependency injection across platforms (Koin Multiplatform)
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.
- 17d ago First seen · 144 lines · 85 tokens per session scan A aeafa16cdc7c
agent-kotlin-expert is a skill published in the GitHub repository travisjneuman/.claude (101 stars, last pushed today), licensed MIT. It adds 85 tokens to every session and 1,461 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-09-30.
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