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 GDvega/super-android-kotlin-firebase-skill --skill kotlin-coregit clone --depth 1 https://github.com/GDvega/super-android-kotlin-firebase-skillWrote 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/gdvega/super-android-kotlin-firebase-skill/kotlin-core)<a href="https://agentmods.dev/skills/gdvega/super-android-kotlin-firebase-skill/kotlin-core"><img src="https://agentmods.dev/badge/skills/gdvega/super-android-kotlin-firebase-skill/kotlin-core/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/gdvega/super-android-kotlin-firebase-skill/kotlin-core"><img src="https://agentmods.dev/badge/skills/gdvega/super-android-kotlin-firebase-skill/kotlin-core.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 | $0.00030 | $0.00580 |
| Opus 5 | $0.00015 | $0.00290 |
| Sonnet 5 | $0.00006 | $0.00116 |
| Haiku 4.5 | $0.00003 | $0.00058 |
Grade A, and why
kotlin-core 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 10d 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 — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Purpose
Keep Kotlin code idiomatic, cancellable, explicit and testable.
When to use
- Refactoring Kotlin domain, data or ViewModel code.
- Modeling UI state, domain results or errors.
- Fixing coroutine, Flow, cancellation or nullability issues.
Inputs to inspect
- Kotlin version and compiler/plugin setup.
- Code under change and tests.
- Coroutine scopes, dispatchers and Flow operators.
- Expected error and state behavior.
Required workflow
- Read the current Kotlin style and version.
- Identify state, error and async boundaries.
- Choose sealed types, Result or domain errors intentionally.
- Preserve cancellation and structured concurrency.
- Add or update unit tests for changed behavior.
Rules
- Never use GlobalScope.
- Do not swallow CancellationException.
- Avoid !! except at hard verified boundaries.
- Keep extension functions focused and discoverable.
- Expose immutable state to consumers.
Related existing skills
Local skills to invoke
- android-architecture
- testing
- dependency-injection
- ui-state-design
External companion skills to use when installed
Do not assume these companion skills are installed. Prefer the local skills above first, then consult Companion Skills for install and verification commands.
- android/skills — use for official Android workflow alignment when a first-party companion skill exists for the task.
Files commonly touched
*.ktViewModel filesdomain modelsrepository interfacestest files
Commands to validate
./gradlew test
./gradlew compileDebugKotlin
./gradlew lint
Common mistakes to avoid
- Launching coroutines without lifecycle or owner scope.
- Mixing UI strings into domain errors.
- Using nullable types where a sealed state is clearer.
- Creating magical extensions that hide side effects.
Checklist
- Nullability explicit.
- Cancellation preserved.
- Flow/state testable.
- Errors modeled.
- Tests added or recommended.
What ships with it
2 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.
- 10d ago First seen · 99 lines · 30 tokens per session scan A 343f16a6add2
kotlin-core is a skill published in the GitHub repository GDvega/super-android-kotlin-firebase-skill (2 stars, last pushed 2mo ago), licensed MIT. It adds 30 tokens to every session and 580 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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