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-chronicle-event-modelinggit 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-chronicle-event-modeling)<a href="https://agentmods.dev/skills/cratis/ai/cratis-chronicle-event-modeling"><img src="https://agentmods.dev/badge/skills/cratis/ai/cratis-chronicle-event-modeling.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 5.1 | $0.00097 | $0.01740 |
| Opus 5 | $0.00048 | $0.00870 |
| Sonnet 5 | $0.00019 | $0.00348 |
| Haiku 4.5 | $0.00010 | $0.00174 |
Grade A, and why
cratis-chronicle-event-modeling 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 — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Chronicle event modeling
Use this before writing code, when behavior, event vocabulary, stream boundaries, or a multi-step flow is not already settled. The output is an implementation brief: which commands exist, which stream each event lands on, which read models consume those events, which automations and translations react, and which specifications prove the flow.
Skip it for a mechanical change where the event types and the flow already exist and the request is wiring or a narrow fix.
Lineage. The four behavior types and the given/when/then-per-behavior discipline follow Event Modeling (Adam Dymitruk; Martin Dilger, Understanding Eventsourcing). This skill applies that method to Chronicle.
Verified product sources
This skill is verified against these exact sources:
| Package | Version | Purpose |
|---|---|---|
Cratis.Chronicle |
16.45.2 |
event types, event-source identities, subjects, [PII] |
Cratis.Chronicle.CodeAnalysis |
16.45.2 |
CHR0012, CHR0026, CHR0034, CHR0035 |
Reverify product sources before claiming support for another version.
The four behavior types
Classify every behavior in the model as exactly one:
| Type | What it does | Built from |
|---|---|---|
| State change | accepts a command, appends events | command, validation, events |
| State view | projects events into a queryable read model | read model plus a projection or a reducer |
| Automation | reacts to events and causes an external side effect | a reactor |
| Translation | reacts to events and appends follow-up events elsewhere | a reactor |
Automation and translation differ in the result: an automation reaches out of the system, a translation stays inside it and produces new facts.
Decide before implementing
- Behavior name and type for each step in the flow.
- Commands — their inputs and the authorization that gates them. Commands are imperative intents.
- Events — past-tense, one-purpose facts. Names must be self-describing:
<Entity><PastTenseVerb>, never a bareCreated. - The event-source id for every event. Events never carry their own event-source id as a payload property; it lives in the event context. Deciding the id is deciding the stream boundary.
- Event properties are non-nullable. Analyzer
CHR0012warns otherwise. Model an optional fact as a separate event, not a nullable field. - Read models — their consumers and their source events, and whether the
model is projection-backed, reducer-backed, or
[Passive]for a strongly-consistent command-side decision. - Automations and translations — which events they react to, whether they emit follow-up events or run commands, and which side effects must not repeat.
- Specifications — the happy path, the validation failures, the constraints, the projections and reducers, and the reactor side effects.
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 · 158 lines · 97 tokens per session scan A d9ef92207625
cratis-chronicle-event-modeling is a skill published in the GitHub repository Cratis/AI (2 stars, last pushed yesterday), licensed MIT. It adds 97 tokens to every session and 1,740 once invoked, about $0.0005 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 2026-09-06.
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