dotnet-core-expert

dotnet-core-expert is a skill for Claude Code, Codex from eric861129/SKILLS_All-in-one. It costs 47 tokens per session (1,132 once invoked), scanned A, a copy of dotnet-core-expert, MIT.

A guide for building C# applications with modern .NET, including web APIs, Blazor web apps, database access, and cloud-oriented services.

In plain words
What is it for?
Use it to create ASP.NET Core APIs and Blazor apps, work with Entity Framework Core, add authentication, apply CQRS patterns, and write xUnit tests.
Why use it?
It provides a structured way to handle API design, asynchronous work, authentication, database changes, performance, and automated tests.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to create ASP.NET Core APIs and Blazor apps, work with Entity Framework Core, add authentication, apply CQRS patterns, and write xUnit tests.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/eric861129/skills_all-in-one/dotnet-core-expert
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 eric861129/SKILLS_All-in-one --skill dotnet-core-expert
Clone the repo
git clone --depth 1 https://github.com/eric861129/SKILLS_All-in-one

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-expert

README.md
[![agentmods](https://agentmods.dev/badge/skills/eric861129/skills_all-in-one/dotnet-core-expert/github.svg)](https://agentmods.dev/skills/eric861129/skills_all-in-one/dotnet-core-expert)
Your own site
<a href="https://agentmods.dev/skills/eric861129/skills_all-in-one/dotnet-core-expert"><img src="https://agentmods.dev/badge/skills/eric861129/skills_all-in-one/dotnet-core-expert/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-expert

Your own site · 80×15
<a href="https://agentmods.dev/skills/eric861129/skills_all-in-one/dotnet-core-expert"><img src="https://agentmods.dev/badge/skills/eric861129/skills_all-in-one/dotnet-core-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,132 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin 94% 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 $0.00047 $0.01132
Opus 5 $0.00023 $0.00566
Sonnet 5 $0.00009 $0.00226
Haiku 4.5 $0.00005 $0.00113

Measured 8d ago against content hash 2fedab16de09, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

dotnet-core-expert scanned grade A with 1 finding 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 8d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

5. **Test** — Write comprehensive tests with xUnit and integration testing; run `dotnet test` to confirm all tests pass — if tests fail, diagnose failures, fix the implementation, and re-run before continuing; verify end
Origin

This is a copy

94% identical to dotnet-core-expert — 2 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.

public/SKILLS/Development & Code Tools/dotnet-core-expert/SKILL.md · 139 lines

How it starts

The opening of the file, as written. The whole thing — 139 lines — stays where its author put it; the contents beside it link to each section on GitHub.

.NET Core Expert

Core Workflow

  1. Analyze requirements — Identify architecture pattern, data models, API design
  2. Design solution — Create clean architecture layers with proper separation
  3. Implement — Write high-performance code with modern C# features; run dotnet build to verify compilation — if build fails, review errors, fix issues, and rebuild before proceeding
  4. Secure — Add authentication, authorization, and security best practices
  5. Test — Write comprehensive tests with xUnit and integration testing; run dotnet test to confirm all tests pass — if tests fail, diagnose failures, fix the implementation, and re-run before continuing; verify endpoints with curl or a REST client

Reference Guide

Load detailed guidance based on context:

Topic Reference Load When
Minimal APIs references/minimal-apis.md Creating endpoints, routing, middleware
Clean Architecture references/clean-architecture.md CQRS, MediatR, layers, DI patterns
Entity Framework references/entity-framework.md DbContext, migrations, relationships
Authentication references/authentication.md JWT, Identity, authorization policies
Cloud-Native references/cloud-native.md Docker, health checks, configuration

Constraints

MUST DO

  • Use .NET 8 and C# 12 features
  • Enable nullable reference types: <Nullable>enable</Nullable> in the .csproj
  • Use async/await for all I/O operations — e.g., await dbContext.Users.ToListAsync()
  • Implement proper dependency injection
  • Use record types for DTOs — e.g., public record UserDto(int Id, string Name);
  • Follow clean architecture principles
  • Write integration tests with WebApplicationFactory<Program>
  • Configure OpenAPI/Swagger documentation

MUST NOT DO

  • Use synchronous I/O operations
  • Expose entities directly in API responses
  • Skip input validation
  • Use legacy .NET Framework patterns
  • Mix concerns across architectural layers
  • Use deprecated EF Core patterns

Read the full file on GitHub · 139 lines

Files

What ships with it

5 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. 8d ago First seen · 139 lines · 47 tokens per session scan A 2fedab16de09

Subscribe to this mod's changes

dotnet-core-expert is a skill published in the GitHub repository eric861129/SKILLS_All-in-one (52 stars, last pushed 4mo ago), licensed MIT. It adds 47 tokens to every session and 1,132 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 94% identical to dotnet-core-expert, differing in 2 lines, and is treated as a copy.

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