C# Conventions
House C# 12 / .NET 8 rules: Result pattern, EF query hygiene, async discipline
Test report
- Verdict
- Tested · Works
- Score
- Tested
- Aug 7, 2026
- Environment
- Claude Code 2.x (agent harness)
Ran it against a deliberately broken ASP.NET Core controller and compared against a no-skill review of the same file. The skill produced seven concrete fixes the plain review did not, including the one genuine latent bug: PurgeInactive sets IsDeleted but no query filters on it, and the skill's global HasQueryFilter convention catches that soft-deleted users keep coming back from GET /users/{id}. It also named exact APIs the generic review only gestured at — AsSplitQuery for the two collection Includes, ExecuteUpdateAsync for the bulk flag flip, IOptions with ValidateOnStart for the stringly-typed API key. Its blind spot is security: the body says nothing about the interpolated FromSqlRaw SQL injection or the hardcoded sa password, both of which the no-skill review caught. 573 words, no scripts and no bundled files to rot, and the repo README's 'CQRS with MediatR' claim for this skill is actually content from the sibling dotnet-core skill.
Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works
- Installs cleanly 5/5
- Triggers reliably 4/5
- Output vs. baseline 7/10
- Docs & honesty 4/5
What C# Conventions does
A compact set of opinionated C# 12 / .NET 8+ conventions covering nullable-as-errors, records and primary constructors, the Result pattern for expected failures, CancellationToken on every async method, IOptions and IHttpClientFactory, and EF Core rules like AsNoTracking, AsSplitQuery, ExecuteUpdateAsync and global soft-delete query filters. It loads whenever you write or review C# in an ASP.NET Core, EF Core or Blazor codebase. Note that despite the repo README, CQRS/MediatR guidance lives in the sibling dotnet-core skill, not here.
How to install C# Conventions
git clone https://github.com/alexander-danilenko/cortex-ai-skills.git
mkdir -p ~/.claude/skills
cd cortex-ai-skills && cp -r skills/csharp ~/.claude/skills/csharp
Skills live in ~/.claude/skills/ (global) or .claude/skills/
(per-project). Restart Claude Code after installing.
Commands — how to trigger C# Conventions
-
/csharpHouse C# 12 / .NET 8 rules: Result pattern, EF query hygiene, async discipline
It also activates on plain-language prompts like these:
-
Review this ASP.NET Core controller for our C# 12 conventions -
Rewrite this EF Core query to use AsNoTracking and AsSplitQuery -
Add CancellationToken and the Result pattern to this async method
Frequently asked questions
- Is the C# Conventions skill free?
- Yes. The skill itself is free from alexander-danilenko/cortex-ai-skills. SkillProof publishes the install command and an independent test verdict at no cost.
- Does C# Conventions work with Claude Code?
- We tested it with Claude Code 2.x (agent harness) on Aug 7, 2026. Verdict: Tested · Works. Ran it against a deliberately broken ASP.NET Core controller and compared against a no-skill review of the same file. The skill produced seven concrete fixes the plain review did not, including the one genuine latent bug: PurgeInactive sets IsDeleted but no query filters on it, and the skill's global HasQueryFilter convention catches that soft-deleted users keep coming back from GET /users/{id}. It also named exact APIs the generic review only gestured at — AsSplitQuery for the two collection Includes, ExecuteUpdateAsync for the bulk flag flip, IOptions with ValidateOnStart for the stringly-typed API key. Its blind spot is security: the body says nothing about the interpolated FromSqlRaw SQL injection or the hardcoded sa password, both of which the no-skill review caught. 573 words, no scripts and no bundled files to rot, and the repo README's 'CQRS with MediatR' claim for this skill is actually content from the sibling dotnet-core skill.
- What is the C# Conventions SkillProof Score?
- 8.0/10 — installs cleanly 5/5, triggers reliably 4/5, output vs. baseline 7/10, docs & honesty 4/5.
- How do I install C# Conventions?
- Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
- Can I use C# Conventions with Cursor, Copilot, Gemini CLI, Codex or other AI tools?
- The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.