cratis-csharp-standards

cratis-csharp-standards is a skill for Claude Code, Codex from Cratis/AI. It costs 101 tokens per session (728 once invoked), scanned A, original, MIT.

A reference for Cratis project conventions in C#, covering formatting, naming, records, nullable values, exceptions, logging, and dependency injection.

In plain words
What is it for?
Use it while writing or reviewing C# in a Cratis project, especially when choosing types, handling nulls, defining exceptions, or applying code style.
Why use it?
It gives developers and coding agents the repository’s specific rules so new C# code fits the existing project style and constraints.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/cratis/ai/cratis-csharp-standards
Any agent
npx skills add Cratis/AI --skill cratis-csharp-standards
Clone the repo
git clone --depth 1 https://github.com/Cratis/AI

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for cratis-csharp-standards

README.md
[![agentmods](https://agentmods.dev/badge/skills/cratis/ai/cratis-csharp-standards.svg)](https://agentmods.dev/skills/cratis/ai/cratis-csharp-standards)
Your own site
<a href="https://agentmods.dev/skills/cratis/ai/cratis-csharp-standards"><img src="https://agentmods.dev/badge/skills/cratis/ai/cratis-csharp-standards.svg" alt="Measured on agentmods" height="20"></a>
Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 728 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00101 $0.00728
Opus 5 $0.00051 $0.00364
Sonnet 5 $0.00020 $0.00146
Haiku 4.5 $0.00010 $0.00073

Measured 3d ago against content hash 15ebd883f5e5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cratis-csharp-standards 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 3d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.ai/skills/cratis-csharp-standards/SKILL.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Key rules (quick reference)

  • Use C# 13 features always — records, primary constructors, pattern matching
  • var over explicit types — the right side already tells you the type
  • File-scoped namespace declarations — one less indentation level
  • using directives: alphabetically sorted, single-line, unused ones removed
  • No regions — if a file needs them, it needs refactoring
  • No postfixes: no Async, Impl, Service, Manager, Handler on class names
  • No Exception suffix on exception types — AuthorNotFound not AuthorNotFoundException
  • Never use built-in exceptions — always create custom exception types
  • record for events, commands, read models, concepts — value equality for free
  • Primary constructors for all types — eliminates field boilerplate
  • is null / is not null — never == null / != null
  • Blank line before opening { of every code block
  • Final return on its own line
  • Private fields: _camelCase with underscore prefix
  • Interfaces: I prefix (IMyService)
  • No [EventType] arguments — the type name is the event identifier
  • [Command] records define Handle() directly — no separate handler classes

Formatting

// File-scoped namespace (no extra indent)
namespace MyApp.Authors.Registration;

// Alphabetically sorted using directives
using Cratis.Arc.Commands;
using Cratis.Chronicle.Events;
using Microsoft.Extensions.Logging;

// Blank line before { of every block
if (condition)
{
    DoSomething();
}

// Expression-bodied for simple members
public string FullName => $"{FirstName} {LastName}";

// Final return on its own line
public string GetName()
{
    var result = BuildName();

    return result;
}

Naming

Artifact Convention Example
Type / method / public member PascalCase RegisterAuthor, AuthorId
Private field _camelCase _eventLog
Local variable camelCase authorId
Interface I prefix IEventLog
Exception type No Exception suffix AuthorNotFound
Feature folder Pluralized domain noun Authors/
Concept file Concept name AuthorId.cs

Read the full file on GitHub · 80 lines

Files

What ships with it

4 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.

Changes

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.

  1. 3d ago First seen · 80 lines · 101 tokens per session scan A 15ebd883f5e5

Subscribe to this mod's changes

cratis-csharp-standards is a skill published in the GitHub repository Cratis/AI (2 stars, last pushed 5d ago), licensed MIT. It adds 101 tokens to every session and 728 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 2026-08-31.

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