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 agentmods add skills/cratis/ai/diagnose-slicenpx skills add Cratis/AI --skill diagnose-slicegit 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/diagnose-slice)<a href="https://agentmods.dev/skills/cratis/ai/diagnose-slice"><img src="https://agentmods.dev/badge/skills/cratis/ai/diagnose-slice.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 | $0.00083 | $0.01468 |
| Opus 5 | $0.00042 | $0.00734 |
| Sonnet 5 | $0.00017 | $0.00294 |
| Haiku 4.5 | $0.00008 | $0.00147 |
Grade A, and why
diagnose-slice 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 today.
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.
Copies of this mod
1 near-identical copy found in the catalogue:
- diagnose-slice — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 49 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Symptom → likely cause → fix for the common ways a Cratis application slice misbehaves. Each row routes to the rule/skill that owns the detail — start there. Reproduce a real defect with a spec before and after the fix.
Backend / Chronicle
| Symptom | Likely cause | Fix → |
|---|---|---|
| Read model query returns empty / stale | projection not wired: event→read-model property names differ (AutoMap only maps matching names), or a default value masks missing wiring | add-projection, cratis-readmodel; [SetFrom<T>] for name diffs; no default values on [ReadModel] props |
| App crashes on startup with a projection error | duplicate [FromEvent<T>] for the same event on one read model |
add-projection (one [FromEvent<T>] per event) |
| Command always "not successful" with no validation errors | [Roles]/authorization: an unauthorized result isn't successful and carries no validation errors |
auth-and-identity, cratis-command; assert ShouldNotBeAuthorized() |
| Command rejected unexpectedly | a CommandValidator/ConceptValidator rule, or Provide() short-circuited with ValidationResult.Error |
add-business-rule, cratis-command |
| Handler returns HTTP 500 instead of rejecting | threw from Provide()/Handle() for a business rule (that's an exception, not a rejection) |
return Result<TEvent, ValidationResult> — add-business-rule |
| Reactor's returned events never appended | returned EventForEventSourceId on a Chronicle version before reactor support |
return event objects, or ReactorSideEffect for another target — reactors.md |
| Projection/reactor stops processing ("quarantined") | a handler threw; the partition paused and the observer quarantined (does not auto-resume) | read the failure off the server first — inspect-running-chronicle; then fix the handler (make it idempotent) and replay — reactors.md |
| Duplicate side effect on replay | non-idempotent reactor without [OnceOnly] |
mark the handler [OnceOnly] — reactors.md |
| Chronicle analyzer warns on an event property | a nullable event property | model the optional fact as a separate event — vertical-slices.md, event-modeling |
| A read model needs a field from another slice | wrong stream boundary / missing event | re-model (information completeness) — event-modeling; never cross-read another read model at runtime |
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.
- today Changed 09fcaaeafc2a
- 3d ago First seen · 49 lines · 83 tokens per session scan A 45839e11e7aa
diagnose-slice is a skill published in the GitHub repository Cratis/AI (2 stars, last pushed today), licensed MIT. It adds 83 tokens to every session and 1,468 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 2026-08-31.
Other skills, from other repositories
diagnose-slice
Use this skill to diagnose why a Cratis slice misbehaves — read model not updating, TypeScript proxy missing, command rejected unexpectedly, projection/observer quarantined, AutoMap mismatch, reactor side effects not appended, or specs flaking. Symptom → likely cause → the rule/skill that owns the fix. Use when…
cratis-readmodel
Step-by-step guidance for creating a Cratis Chronicle read model from scratch — defining events, choosing between projection and reducer, [ReadModel] record with static query methods, and the generated TypeScript proxy in React. Use when creating a read model, working with [EventType], [ReadModel], IProjectionFor…
add-projection
Use this skill when asked to add a Chronicle projection to a Cratis-based project. Favor model-bound projections by default, and only fall back to declarative/fluent IProjectionFor projections when model-bound attributes cannot express the behavior cleanly. Enforces the AutoMap-first rule and Chronicle-specific join…
cratis-vertical-slice
Explains how vertical feature slices are structured in a Cratis Chronicle + Arc application — folder layout, the single backend .cs file, the four slice types (State Change/View/Automation/Translation), and how features compose slices. Use when asking how slices work, where files go, or which slice type to choose. To…
create-event-model
Create and maintain Mermaid eventmodeling diagrams (EventModel.md) for a Cratis module or feature. Use when adding, renaming, moving, or deleting modules/features/slices, commands, events, read models, automations, translations, or cross-module event flows — to keep the diagram in sync with the code.
write-specs-readmodels
Use this skill when asked to write tests or specs for read model projections, reducers, or model-bound projections using ReadModelScenario in a Cratis-based project. Produces infrastructure-free in-process specs using ReadModelScenario .