What is hotpath-profiler-assistant?

A guide for profiling .NET applications to find where CPU time, memory allocations, or other resources are actually being spent. It helps choose and use tools such as dotnet-trace, dotnet-counters, and PerfView.

Use it to investigate slow endpoints, high CPU, latency spikes, memory leaks, or unclear performance bottlenecks in a .NET app.

It prevents developers from optimizing code that is not causing the slowdown. It also gives a way to capture and interpret performance data instead of guessing.

hotpath-profiler-assistant — Skill for Claude Code by StefanTheCode

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 StefanTheCode/dotnet-ai-toolkit --skill hotpath-profiler-assistant

Clone the repo

git clone --depth 1 https://github.com/StefanTheCode/dotnet-ai-toolkit

Made for: Claude Code.

Or install dotnet-ai-toolkit, the plugin that ships this one along with the rest of its 49 skills.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant/github.svg)](https://agentmods.dev/skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant)

Your own site

<a href="https://agentmods.dev/skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant"><img src="https://agentmods.dev/badge/skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant"><img src="https://agentmods.dev/badge/skills/stefanthecode/dotnet-ai-toolkit/hotpath-profiler-assistant.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 123 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 672 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.

Model	Per session	Once invoked
Fable 5.1	$0.00123	$0.00672
Opus 5.5	$0.00049	$0.00269
Sonnet 5.5	$0.00025	$0.00134
Haiku 4.5	$0.00012	$0.00067

Measured 2mo ago against content hash 54d9c181f494, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

hotpath-profiler-assistant 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 2mo 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.

skills/hotpath-profiler-assistant/SKILL.md · 43 lines

How it starts

The opening of the file, as written. The whole thing — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hot-Path Profiler Assistant

Find where time and allocations actually go before optimizing anything — pick the right tool, capture a useful trace, and interpret it. Stops premature optimization of cold code.

Input — point it at your project / describe the symptom

Works on a target (a project or GitHub URL) for context, plus the symptom (slow endpoint, high CPU, latency spikes). If they have a trace already, go to interpretation.

Pick the tool

dotnet-counters — live, low-overhead metrics (CPU, GC, thread pool, requests). Start here to see what kind of problem it is.
dotnet-trace — sampling/event trace of CPU time; cross-platform; open in Speedscope/PerfView. Best for "where is CPU spent".
dotnet-gcdump / dotnet-dump — heap snapshots for memory leaks/retention.
PerfView (Windows) — deep ETW analysis, allocation tick, GC.
VS / Rider profiler — IDE-integrated, friendly flame graphs.

Capture (examples)

dotnet-counters monitor -p <pid>
dotnet-trace collect -p <pid> --duration 00:00:30        # then open the .nettrace in speedscope.app
dotnet-gcdump collect -p <pid>                           # heap snapshot

For an endpoint, drive load while capturing (e.g. bombardier/k6) so the hot path is exercised.

Reading it

Flame graph width = time — widest frames are where you optimize. Ignore narrow ones.
Separate CPU-bound (busy frames) from wait (async/IO) — different fixes.
Check allocations alongside CPU — GC time can masquerade as slowness.
Confirm the suspected method is actually hot before touching it.

Principles

Profile first, optimize second. Most "obvious" bottlenecks are wrong guesses.
Measure under realistic load, not a single cold request.
Optimize the widest frame, re-measure, repeat — don't shotgun.

How to use it & best prompts

"What's slow in my app", "where's the bottleneck in this endpoint", "how do I capture a CPU trace", "read this flame graph / trace". Feeds into benchmarkdotnet-setup, memory-allocation-analyzer, gc-pressure-auditor.

Read the full file on GitHub · 43 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.

USAGE.md 1021 B

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.

2mo ago First seen · 43 lines · 123 tokens per session scan A 54d9c181f494

Subscribe to this mod's changes

hotpath-profiler-assistant is a skill published in the GitHub repository StefanTheCode/dotnet-ai-toolkit (26 stars, last pushed 2mo ago), licensed MIT. It adds 123 tokens to every session and 672 once invoked, about $0.0005 per session on Opus 5.5. 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.

C# and .NET Debugging Languages performance

hotpath-profiler-assistant next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
hotpath-profiler-assistantStefanTheCode/dotnet-ai-toolkit	Skill	26	2mo ago	MIT	A	123	Claude Code
dotnet-reversezhaoxuya520/reverse-skill	Skill	44k	1mo ago	MIT	A	144	Claude Code
check-bin-obj-clashdotnet/skills	Skill	5.8k	yesterday	MIT	A	160	Claude Code
winforms-expertdotnet/skills	Skill	5.8k	yesterday	MIT	A	137	Claude Code
build-perf-diagnosticsdotnet/skills	Skill	5.8k	yesterday	MIT	A	133	Claude Code
dump-collectdotnet/skills	Skill	5.8k	yesterday	MIT	A	96	Claude Code
binlog-generationdotnet/skills	Skill	5.8k	yesterday	MIT	A	149	Claude Code