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dotPilot: Skill for Codex

.codex/skills/mcaf-dotnet-features/SKILL.md

mcaf-dotnet-features is a skill for Codex from managedcode/dotPilot. It costs 54 tokens per session (1,183 once invoked), scanned A, a copy of dotnet-modern-csharp, MIT.

Guidance for choosing modern C# language features that work with a repository’s .NET version and language settings.

In plain words
What is it for?
Use it when writing or reviewing C# code, especially when deciding whether C# 13 or C# 14 features are compatible with the project.
Why use it?
It prevents code from using C# features that the project’s compiler or target framework cannot support. It also helps teams make consistent choices when upgrading C# versions.

Skill for Codex

Written for Codex: installed under .codex/. Also seen: mentions AGENTS.md.

This is managedcode/dotPilot's own configuration. It tells Codex how to work on dotPilot itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything dotPilot configures →

not rated 25repo 6mo ago A scan 54 tokens copy · 95% MIT
View source ↗ managedcode/dotPilot dotpilot.managed-code.com
Reuse

Borrowing it

Nothing to install: this file belongs to managedcode/dotPilot. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/managedcode/dotPilot/main/.codex/skills/mcaf-dotnet-features/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/managedcode/dotPilot

Made for: 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.

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README.md
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Your own site
<a href="https://agentmods.dev/skills/managedcode/dotpilot/mcaf-dotnet-features"><img src="https://agentmods.dev/badge/skills/managedcode/dotpilot/mcaf-dotnet-features/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for mcaf-dotnet-features

Your own site · 80×15
<a href="https://agentmods.dev/skills/managedcode/dotpilot/mcaf-dotnet-features"><img src="https://agentmods.dev/badge/skills/managedcode/dotpilot/mcaf-dotnet-features.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,183 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 95% copy Near-identical to another mod 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 5.1 $0.00054 $0.01183
Opus 5.5 $0.00022 $0.00473
Sonnet 5.5 $0.00011 $0.00237
Haiku 4.5 $0.00005 $0.00118

Measured 1mo ago against content hash 7e8e6c71f68b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcaf-dotnet-features 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 1mo 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

This is a copy

95% identical to dotnet-modern-csharp — 16 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.codex/skills/mcaf-dotnet-features/SKILL.md · 118 lines

How it starts

The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCAF: .NET Features

Trigger On

  • the repo wants more modern idiomatic C# code
  • a change depends on language-version compatibility
  • the team is upgrading or reviewing C# feature usage across versions
  • you need to know whether a C# 13 or C# 14 feature is safe to use

Value

  • produce a concrete project delta: code, docs, config, tests, CI, or review artifact
  • reduce ambiguity through explicit planning, verification, and final validation skills
  • leave reusable project context so future tasks are faster and safer

Do Not Use For

  • non-C# .NET languages such as F# or VB
  • analyzer-only or formatter-only setup with no language feature choice

Inputs

  • target TFM or TFMs
  • explicit LangVersion, if any
  • current SDK version
  • team style rules in .editorconfig and AGENTS.md

Quick Start

  1. Read the nearest AGENTS.md and confirm scope and constraints.
  2. Run this skill's Workflow through the Ralph Loop until outcomes are acceptable.
  3. Return the Required Result Format with concrete artifacts and verification evidence.

Workflow

  1. Detect the real language ceiling from the repo's target framework and explicit LangVersion.
  2. Prefer stable features that the current repo actually supports.
  3. Use modern syntax when it reduces ceremony, improves correctness, or makes invariants clearer.
  4. Do not mass-rewrite a codebase into newer syntax unless the repo wants that churn.
  5. Treat preview features as opt-in only. Never assume preview because the current machine has a newer SDK.
  6. Pay special attention to C# 13 and C# 14:
    • C# 13 is the stable language for .NET 9
    • C# 14 is the stable language for .NET 10
  7. When feature selection changes architecture, style rules, or generated-code patterns, coordinate with:
    • mcaf-dotnet
    • mcaf-dotnet-analyzer-config
    • mcaf-solid-maintainability
  8. After feature-driven refactors, run the repo's .NET quality pass through mcaf-dotnet.

Bootstrap When Missing

If the requested C# feature depends on SDK or language support the repo does not have yet:

Read the full file on GitHub · 118 lines

Files

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.

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. 1mo ago First seen · 118 lines · 54 tokens per session scan A 7e8e6c71f68b

Subscribe to this mod's changes

mcaf-dotnet-features is a skill published in the GitHub repository managedcode/dotPilot (25 stars, last pushed 6mo ago), licensed MIT. It adds 54 tokens to every session and 1,183 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 95% identical to dotnet-modern-csharp, differing in 16 lines, and is treated as a copy.

C# and .NETLanguagesagent-frameworkagent-orchestrationai-agentsai-toolsdesktop-appdotnet
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