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 Cratis/AI --skill cratis-application-slice-specificationsgit clone --depth 1 https://github.com/Cratis/AIWrote 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/cratis/ai/cratis-application-slice-specifications)<a href="https://agentmods.dev/skills/cratis/ai/cratis-application-slice-specifications"><img src="https://agentmods.dev/badge/skills/cratis/ai/cratis-application-slice-specifications/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/cratis/ai/cratis-application-slice-specifications"><img src="https://agentmods.dev/badge/skills/cratis/ai/cratis-application-slice-specifications.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 | $0.00087 | $0.02485 |
| Opus 5 | $0.00044 | $0.01242 |
| Sonnet 5 | $0.00017 | $0.00497 |
| Haiku 4.5 | $0.00009 | $0.00248 |
Grade A, and why
cratis-application-slice-specifications 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.
How it starts
The opening of the file, as written. The whole thing — 223 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cratis application slice specifications
A slice is specified from the outside, through the pipeline it actually runs on. The scenario family exercises the real Arc and Chronicle code paths in-process — no HTTP, no fixture, no server — so a specification says what the slice does rather than what its classes do.
This skill decides which scenario and what to cover. The C# mechanics
(Establish/Because, substitutes, contexts) live in
cratis-specifications-csharp.
Verified product sources
| Package | Version | Purpose |
|---|---|---|
Cratis.Arc.Testing |
22.10.4 |
CommandScenario<TCommand> and the CommandResult assertions |
Cratis.Arc.Chronicle.Testing |
22.10.4 |
Given, EventLog, AppendedEvents and the appended-event assertions on a command scenario |
Cratis.Chronicle.Testing |
16.45.2 |
EventScenario, ReadModelScenario<T>, ReactorScenario<T> |
Cratis.Specifications.XUnit |
4.x |
The Specification base and the ShouldXxx assertions |
Cratis.Testing is the meta-package that brings Cratis.Arc.Testing and
Cratis.Arc.Chronicle.Testing together. Reverify against the owning product
repository before claiming support for another version.
Route near misses
- The repository builds a Cratis library rather than an application: use
cratis-specifications-csharpand stay on the plainSpecificationbase. - React, TypeScript, or a view model: use
cratis-application-react-specifications. - The subject is append semantics or a constraint on its own: use
cratis-chronicle-event-specifications. - The subject is a projection or reducer on its own: use
cratis-chronicle-read-model-specifications. - The question is what the slice should do: settle the behavior first. A specification records a decision; it does not make one.
Step 1 — Place the files
Specifications live in the slice folder, beside the .cs they specify, each
file wrapped in #if DEBUG … #endif so specification code compiles only in
Debug.
What ships with it
1 file 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.
- yesterday First seen · 223 lines · 87 tokens per session scan A 257fa952b370
cratis-application-slice-specifications is a skill published in the GitHub repository Cratis/AI (2 stars, last pushed today), licensed MIT. It adds 87 tokens to every session and 2,485 once invoked, about $0.0004 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 2026-09-08.
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