dotnet-core

dotnet-core is a skill for Claude Code, Codex from adonai-labs/agent-runway. It costs 120 tokens per session (855 once invoked), scanned A, original, MIT.

A guide for building .NET applications in C#, including common patterns for web APIs, databases, testing, security, and monitoring.

In plain words
What is it for?
Use it to structure ASP.NET Core applications, write EF Core database queries and migrations, design APIs, add messaging or caching, and improve logging and tests.
Why use it?
It helps you make stack-specific implementation choices without relying on generic advice that may not fit .NET 8 or 9.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Claude Code.

Good fit Use it to structure ASP.NET Core applications, write EF Core database queries and migrations, design APIs, add messaging or caching, and improve logging and tests.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/adonai-labs/agent-runway/skill-dotnet-core
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.

Any agent
npx skills add adonai-labs/agent-runway --skill skill-dotnet-core
Clone the repo
git clone --depth 1 https://github.com/adonai-labs/agent-runway

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 dotnet-core

README.md
[![agentmods](https://agentmods.dev/badge/skills/adonai-labs/agent-runway/skill-dotnet-core/github.svg)](https://agentmods.dev/skills/adonai-labs/agent-runway/skill-dotnet-core)
Your own site
<a href="https://agentmods.dev/skills/adonai-labs/agent-runway/skill-dotnet-core"><img src="https://agentmods.dev/badge/skills/adonai-labs/agent-runway/skill-dotnet-core/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 dotnet-core

Your own site · 80×15
<a href="https://agentmods.dev/skills/adonai-labs/agent-runway/skill-dotnet-core"><img src="https://agentmods.dev/badge/skills/adonai-labs/agent-runway/skill-dotnet-core.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 120 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 855 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 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 5.1 $0.00120 $0.00855
Opus 5 $0.00060 $0.00428
Sonnet 5 $0.00024 $0.00171
Haiku 4.5 $0.00012 $0.00085

Measured 6d ago against content hash 08b6db97ff5e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

dotnet-core 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 6d 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.

src/stacks/dotnet/skill-dotnet-core/SKILL.md · 76 lines

How it starts

The opening of the file, as written. The whole thing — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.

.NET Core

How to invoke

After agent-runway add dotnet, the skill is installed at .cursor/skills/dotnet-core/. Use:

  • Cursor: @dotnet-core or ask a .NET question while editing *.cs (rules auto-attach)
  • Claude Code: reference .agent-runway/skills/dotnet-core/SKILL.md or ask in context of C# files

Examples:

  • How should I structure this CQRS handler?
  • Is this EF Core query likely to cause N+1?
  • How do I test this application service?
  • How do I add structured logging with correlation here?

Not sure which skill to use? Start with /start — it classifies intent and routes to the right skill.


Role

Act as a senior .NET engineer with deep experience in ASP.NET Core, EF Core, clean architecture, CQRS, testing, and Azure-hosted .NET systems.

This skill is .NET and C# specific. For system design, trade-off reasoning, and architecture proposals, combine with the architect skill.


What this skill helps with

  • Applying Clean Architecture, CQRS/MediatR, and feature-first organisation in .NET
  • EF Core patterns, DbContext design, migrations, and query correctness
  • Infrastructure integration: messaging, HTTP clients, caching, configuration, secrets
  • Observability: structured logging, correlation, tracing, metrics, health checks in .NET
  • ASP.NET Core API design: Minimal APIs, controllers, validation, middleware, auth
  • Testing: unit, integration, functional, and service-level tests with .NET tooling
  • Security: input validation, authorisation, secrets management in .NET context

How to use this skill

For implementation questions

  1. Identify what concern the question touches
  2. Load the relevant reference file below
  3. Apply the patterns and rules; highlight divergence with reasons

For implementation reviews

  1. Check against the relevant file for the concern
  2. Surface findings with line-level specifics where possible
  3. Classify as: correct, concern (non-blocking), or violation (blocking)

For new features

  1. Follow the guidance in architecture.md for structural placement
  2. Apply application patterns from application-patterns.md
  3. Apply infrastructure patterns from infrastructure.md
  4. Ensure observability from observability.md
  5. Ensure tests following testing.md

Read the full file on GitHub · 76 lines

Files

What ships with it

8 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. 6d ago First seen · 76 lines · 120 tokens per session scan A 08b6db97ff5e

Subscribe to this mod's changes

dotnet-core is a skill published in the GitHub repository adonai-labs/agent-runway (2 stars, last pushed 20d ago), licensed MIT. It adds 120 tokens to every session and 855 once invoked, about $0.0006 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 2026-09-03.

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