dotnet-microsoft-extensions

Guidance for using Microsoft.Extensions, a shared set of .NET tools for dependency injection, configuration, logging, application startup, and HTTP clients.

In plain words
What is it for?
Wiring application services, adding a Generic Host, binding and validating settings, configuring logging, and creating managed outbound HTTP clients.
Why use it?
It helps keep .NET application setup consistent and avoids fragile service registration, configuration, logging, or network-client code.

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/managedcode/prompterone/dotnet-microsoft-extensions
Any agent
npx skills add managedcode/PrompterOne --skill dotnet-microsoft-extensions
Clone the repo
git clone --depth 1 https://github.com/managedcode/PrompterOne

Made for: Claude Code, Codex.

Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 390 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 $0.00036 $0.00390
Opus 5 $0.00018 $0.00195
Sonnet 5 $0.00007 $0.00078
Haiku 4.5 $0.00004 $0.00039

Measured 2d ago against content hash a18f8b53ae2e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

dotnet-microsoft-extensions 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 2d 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:

.codex/skills/dotnet-microsoft-extensions/SKILL.md · 40 lines

What it actually says

Microsoft.Extensions for .NET

Trigger On

  • wiring dependency injection, configuration, logging, or options
  • introducing Generic Host patterns into non-web .NET apps
  • cleaning up service registration, typed HTTP clients, or shared infrastructure code

Workflow

  1. Prefer the Generic Host for apps that need configuration, DI, logging, hosted services, or coordinated startup.
  2. Keep service registration predictable: composition at the edge, concrete implementations hidden behind interfaces only where that abstraction buys flexibility.
  3. Use options binding for structured configuration and validate configuration at startup when bad settings would fail later at runtime.
  4. Prefer IHttpClientFactory and typed or named clients for outbound HTTP instead of ad-hoc singleton or per-call HttpClient usage.
  5. Use logging categories and config-driven log levels rather than scattered ad-hoc logging behavior.
  6. Avoid building mini-frameworks over Microsoft.Extensions unless the repo genuinely needs reusable composition primitives.

Deliver

  • clean host wiring and service registration
  • configuration and logging that are observable and testable
  • infrastructure code that fits naturally with the .NET stack

Validate

  • service lifetimes are correct
  • configuration is strongly typed where it matters
  • host setup remains easy to debug and reason about

References

  • patterns.md - DI patterns, Configuration patterns, Options pattern, Logging patterns, HttpClientFactory patterns, Hosted Service patterns
  • anti-patterns.md - Common mistakes with DI, configuration, options, logging, HttpClient, and hosted services
Files

What ships with it

3 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. 2d ago First seen · 40 lines · 36 tokens per session scan A a18f8b53ae2e

Subscribe to this mod's changes

dotnet-microsoft-extensions is a skill published in the GitHub repository managedcode/PrompterOne (42 stars, last pushed 3mo ago), licensed MIT. It adds 36 tokens to every session and 390 once invoked, about $0.0002 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 2026-08-30.

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