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-engineering-effect-boundariesgit 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-engineering-effect-boundaries)<a href="https://agentmods.dev/skills/cratis/ai/cratis-engineering-effect-boundaries"><img src="https://agentmods.dev/badge/skills/cratis/ai/cratis-engineering-effect-boundaries.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 | $0.00080 | $0.01661 |
| Opus 5 | $0.00040 | $0.00830 |
| Sonnet 5 | $0.00016 | $0.00332 |
| Haiku 4.5 | $0.00008 | $0.00166 |
Grade A, and why
cratis-engineering-effect-boundaries 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.
How it starts
The opening of the file, as written. The whole thing — 131 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Effect boundaries fail loudly
An effect boundary is the point where work leaves the process and becomes something other people observe: a package published, a row written, a file generated, content propagated to other repositories, a release cut.
The contract:
On an effect boundary, partial success is failure. No catch-and-continue, no defaulting to success on an unknown outcome. A degraded operation must fail the operation, surface the delta, or emit an explicit degraded-mode signal.
Silent failure is the dominant recurring bug archetype across Cratis. The 2026-08-24 organization-wide review found one disease with six manifestations, in the release action, the Arc proxy generator, Stage, the Chronicle container host, Chronicle constraint enforcement, and corpus propagation. They are written out in failure-archetypes.md; read them before deciding that your case is different.
When you need this
- You are writing or reviewing a
catcharound an operation with an effect — publish, write, generate, copy, notify, tag, release. - An operation processes a set and some members can fail independently: a fan-out, a batch, a matrix, a per-file generator.
- A call returns an outcome you did not model: an unexpected status code, a null, an empty result, a timeout.
- Two implementations of one interface exist and only one of them really enforces the behavior — an in-memory or SQL sibling of a real store.
- A host, container, or long-running process can reach a "started" state while the thing it started has already thrown.
When you do not
- Pure computation with no effect. A parser that returns a partial tree for a caller that inspects it is not an effect boundary.
- A retry that will still report the final outcome truthfully. Retrying is not swallowing; reporting success after the retries also failed is.
- A genuinely optional enrichment whose absence is stated in the result. An
optional cache warm that records
cache: skippedis a degraded-mode signal, which is exactly what this contract asks for. - Style, naming, or structure questions. Those belong to the C# and TypeScript conventions.
- Deciding whether an operation should exist at all. That is a product or scope ruling, not an error-handling one.
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.
- today First seen · 131 lines · 80 tokens per session scan A 6aaa05d8f59a
cratis-engineering-effect-boundaries is a skill published in the GitHub repository Cratis/AI (2 stars, last pushed yesterday), licensed MIT. It adds 80 tokens to every session and 1,661 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.
Other skills, from other repositories
dotnet-techne-refactor-pipeline
Use when the user asks for a phase-gated refactoring or redesign loop - session-blind workers map and trace the area, empirical probes precede the design, an approval gate guards implementation, and a conformance audit re-checks the branch after any design change. State persists in .episteme/DESIGN- .md. Requires the…
code-janitor
Periodic codebase hygiene agent. Tracks health metrics, reports risky patterns, makes only zero-risk changes, files tickets for anything that needs judgment.
nodejs-best-practices
Audit toàn diện Node.js project (Express/NestJS/Fastify + TypeScript). Phát hiện violations bằng regex patterns, chấm điểm theo domain có trọng số. Tất cả nội dung báo cáo bằng tiếng Việt.
gsd-ns-review
Route to the appropriate quality / review skill based on the user's intent. gsd-code-review-fix was absorbed by gsd-code-review --fix in #2790.
issue
Use when starting a chain from a GitHub issue — turning an issue URL or number into a triaged, planned, dispatched, and reviewed pull request. Classifies the thread (bug → root-cause discipline, feature → plan chain, question → drafted reply), synthesizes a spec from the issue's own acceptance criteria, then runs the…
karpathy-guidelines
Surgical execution guardrails for coding, debugging, review, and refactor tasks.