dotnet-async-performance-specialist

dotnet-async-performance-specialist is an agent for Claude Code from novotnyllc/dotnet-artisan. It costs 68 tokens per session (1,772 once invoked), scanned A, original, MIT.

A .NET adviser for asynchronous code and runtime efficiency. It reviews async/await, ValueTask, ConfigureAwait, IO.Pipelines, ThreadPool settings, and Channel choices.

In plain words
What is it for?
Use it to review asynchronous code, choose between Task and ValueTask, assess ConfigureAwait usage, examine pipelines or channels, and investigate ThreadPool performance.
Why use it?
It helps find unnecessary overhead and incorrect choices in code that performs work without blocking a thread. It also distinguishes performance questions from profiling and concurrency-bug investigations.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter; mentions subagents.

Part of the dotnet-artisan plugin — 9 skills, 14 agents, 2 MCP servers shipped together

Good fit Use it to review asynchronous code, choose between Task and ValueTask, assess ConfigureAwait usage, examine pipelines or channels, and investigate ThreadPool performance.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/novotnyllc/dotnet-artisan/dotnet-async-performance-specialist
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.

Clone the repo
git clone --depth 1 https://github.com/novotnyllc/dotnet-artisan

Made for: Claude Code.

Or install dotnet-artisan, the plugin that ships this one along with the rest of its 9 skills, 14 agents, 2 MCP servers.

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-async-performance-specialist

README.md
[![agentmods](https://agentmods.dev/badge/agents/novotnyllc/dotnet-artisan/dotnet-async-performance-specialist.svg)](https://agentmods.dev/agents/novotnyllc/dotnet-artisan/dotnet-async-performance-specialist)
Your own site
<a href="https://agentmods.dev/agents/novotnyllc/dotnet-artisan/dotnet-async-performance-specialist"><img src="https://agentmods.dev/badge/agents/novotnyllc/dotnet-artisan/dotnet-async-performance-specialist.svg" alt="Measured on agentmods" height="20"></a>
Per session 68 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,772 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 $0.00068 $0.01772
Opus 5 $0.00034 $0.00886
Sonnet 5 $0.00014 $0.00354
Haiku 4.5 $0.00007 $0.00177

Measured 8d ago against content hash 44afe25e2a6c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

dotnet-async-performance-specialist 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 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.

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.

plugins/dotnet-artisan/agents/dotnet-async-performance-specialist.md · 125 lines

How it starts

The opening of the file, as written. The whole thing — 125 lines — stays where its author put it; the contents beside it link to each section on GitHub.

dotnet-async-performance-specialist

Async performance analysis subagent for .NET projects. Performs read-only analysis of async/await patterns and runtime performance to identify overhead, recommend optimizations, and guide architectural decisions. Grounded in guidance from Stephen Toub's .NET performance blog series, ConfigureAwait FAQ, and async internals deep-dives.

Knowledge Sources

This agent's guidance is grounded in publicly available content from:

  • Stephen Toub's .NET Performance Blog -- Deep-dives on async internals, ValueTask design, ConfigureAwait behavior, and runtime performance across .NET releases. Source: https://devblogs.microsoft.com/dotnet/author/toub/
  • ConfigureAwait FAQ (Stephen Toub) -- When ConfigureAwait(false) is needed vs unnecessary. Key insight: not needed in ASP.NET Core app code (.NET Core+), still recommended in library code targeting both Framework and Core. Source: https://devblogs.microsoft.com/dotnet/configureawait-faq/
  • Async Internals -- State machine compilation, ExecutionContext flow, SynchronizationContext capture, and the cost model of async/await.
  • Stephen Cleary's "Concurrency in C#" and Blog -- Async best practices, SynchronizationContext behavior, Task vs ValueTask guidance, and correct cancellation patterns. Key insight: "There is no thread" -- async I/O completions do not block a thread while waiting; understanding this is essential for correct async reasoning. Also covers async disposal patterns, async initialization, and Channel-based producer-consumer. Source: https://blog.stephencleary.com/ and "Concurrency in C#" (O'Reilly)

Disclaimer: This agent applies publicly documented guidance. It does not represent or speak for the named knowledge sources.

Preloaded Skills

Always load these skills before analysis:

  • [skill:dotnet-csharp] (read references/async-patterns.md) -- async/await correctness, Task patterns, cancellation, ConfigureAwait
  • [skill:dotnet-tooling] (read references/performance-patterns.md) -- Span, ArrayPool, sealed classes, struct design for hot paths
  • [skill:dotnet-tooling] (read references/profiling.md) -- dotnet-counters, dotnet-trace, and diagnostic tool interpretation
  • [skill:dotnet-csharp] (read references/channels.md) -- Channel producer-consumer patterns, bounded vs unbounded, backpressure

Read the full file on GitHub · 125 lines

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 · 125 lines · 68 tokens per session scan A 44afe25e2a6c

Subscribe to this mod's changes

dotnet-async-performance-specialist is an agent published in the GitHub repository novotnyllc/dotnet-artisan (229 stars, last pushed 21d ago), licensed MIT. It adds 68 tokens to every session and 1,772 once invoked, about $0.0003 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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