Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/managedcode/dotnet-skillsnpx agentmods add skills/managedcode/dotnet-skills/blazing-fast-dotnetWrote 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.
[](https://agentmods.dev/skills/managedcode/dotnet-skills/blazing-fast-dotnet)<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/blazing-fast-dotnet"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/blazing-fast-dotnet/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.
<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/blazing-fast-dotnet"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/blazing-fast-dotnet.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00072 | $0.05687 |
| Opus 5.5 | $0.00029 | $0.02275 |
| Sonnet 5.5 | $0.00014 | $0.01137 |
| Haiku 4.5 | $0.00007 | $0.00569 |
Grade A, and why
blazing-fast-dotnet 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 today.
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.
How it starts
The opening of the file, as written. The whole thing — 347 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Blazing Fast .NET Performance
[!WARNING] Much of the advice here might not age well: as .NET evolves, old hacks and custom knobs may become obsolete or even detrimental. Apply only after careful consideration and testing. Revisit periodically to ensure continued relevance.
This skill focuses on optimizing .NET applications for maximum performance, providing tips, techniques, and best practices to achieve blazing-fast execution times. It targets .NET 10.0 and 11.0. Older versions have not been tested.
Contents
- Magic knobs to Tune .NET Performance
- NativeAOT-specific tuning
- Profiling and Performance Analysis
- Best practices for high-performance C# code
- ASP.NET Core
Magic knobs to Tune .NET Performance
[!WARNING] It is highly recommended to keep the default settings unless you have measured and understood the performance implications of changing them.
⭐ - known to have a visible impact on performance (typically, in synthetic benchmarks).
| Environment variable (CoreCLR Release, .NET 10.0+) | Default | Values to try | Purpose and trade-offs |
|---|---|---|---|
⭐DOTNET_SYSTEM_NET_SOCKETS_INLINE_COMPLETIONS |
0 |
1 |
Run I/O continuations directly on poller threads instead of dispatching them to workers - beneficial for workloads with many small requests. ⚠️ Blocking or lengthy continuations can stall I/O ⚠️ |
⭐DOTNET_ThreadPool_UnfairSemaphoreSpinLimit |
70 in .NET 10.0; 1024 in current .NET 11.0 |
0, 0x400, 0xC00 |
Trade worker wake latency against CPU spent spinning. 0 might be useful as a mitigation for high CPU usage (especially on arm64) at the cost of throughput. Large values might improve synthetic benchmark performance. |
⭐DOTNET_GCDynamicAdaptationMode |
1 |
0 |
Disable DATAS for server GC. Can improve throughput at the expense of memory; compare against tuning DATAS (e.g. DOTNET_GCDGen0GrowthPercent) rather than disabling it. |
⭐DOTNET_HillClimbing_Disable |
0 |
1 |
Disable ThreadPool hill climbing (improves time to steady state). |
DOTNET_SYSTEM_NET_SOCKETS_THREAD_COUNT |
Automatic; processor count when inline completions are enabled | 1, 2, 4, 8, up to processor count |
Tune I/O poller count. Fewer pollers can reduce scheduling and cache overhead; too few can serialize processing. Values are decimal. |
DOTNET_gcServer |
varies by environment | 1 |
Typically enabled by default for server workloads. Might improve the performance of desktop/console tools. |
DOTNET_GCDTargetTCP |
Effective target 2% (configuration 0) |
1 |
Lower DATAS's target throughput-cost percentage. Encourages more heaps when GC cost exceeds the target. Only relevant with DATAS enabled. |
DOTNET_GCDGen0GrowthPercent |
Effective multiplier 100% (configuration 0) |
0xC8 |
Scale DATAS's gen0 budget multiplier to 200% of its default. Trades memory for potentially fewer collections. Only relevant with DATAS enabled. |
DOTNET_TC_CallCountingDelayMs |
100 ms; longer on a single processor |
0 |
Only for short-lived console tools where JIT warmup takes too long: remove the tiering delay while retaining the normal call-count threshold. Can increase compilation work early in execution. |
DOTNET_TieredCompilation |
1 |
0 |
Alternative for short-lived console tools where JIT warmup takes too long: disable tiering and JIT optimized code on first use. Removes tiered warmup but disables dynamic PGO and can increase initial JIT cost. |
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.
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.
- today First seen · 347 lines · 72 tokens per session scan A b1bc0a5ba242
blazing-fast-dotnet is a skill published in the GitHub repository managedcode/dotnet-skills (493 stars, last pushed yesterday), licensed MIT. It adds 72 tokens to every session and 5,687 once invoked, about $0.0003 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 2026-10-24.
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