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.
git clone --depth 1 https://github.com/beel-collab/presets.devWrote 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/rules/beel-collab/presets.dev/dotnet-rules)<a href="https://agentmods.dev/rules/beel-collab/presets.dev/dotnet-rules"><img src="https://agentmods.dev/badge/rules/beel-collab/presets.dev/dotnet-rules/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/rules/beel-collab/presets.dev/dotnet-rules"><img src="https://agentmods.dev/badge/rules/beel-collab/presets.dev/dotnet-rules.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 | $0.00000 | $0.01070 |
| Opus 5.5 | $0.00000 | $0.00428 |
| Sonnet 5.5 | $0.00000 | $0.00214 |
| Haiku 4.5 | $0.00000 | $0.00107 |
Grade A, and why
dotnet-rules 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 — 106 lines — stays where its author put it; the contents beside it link to each section on GitHub.
.NET Rules for Cursor: Nullable Contracts, Async and Endpoints
Install
Install the native export at .cursor/rules/dotnet-rules.mdc.
Copy that export, not this catalog file. Catalog fields such as tools and author are for presets.dev.
Install one skill file per name. Cursor, GitHub Copilot, Codex, Antigravity CLI, and Devin can all read .agents/skills, so a second copy with the same name collides.
.NET Rules for Cursor: Nullable Contracts, Async and Endpoints
File-scoped Cursor rule for .NET. It attaches when a matching file is in context.
Updated for .NET 10 LTS and .NET 11, Nov 2026
Do not upgrade dependencies or the framework version unless the task asks.
.NET 11 includes C# 15 unions and closed hierarchies. A project that still targets .NET 10 LTS does not get that syntax. Read the TargetFramework before you write a language feature. Do not retarget the project unless the task asks. Nullable reference types stay enabled when the project has them on.
Project shape
Match the existing minimal API or controller style. A handler is small. Domain rules live in a type the handler calls. Do not grow a static Program.cs into the place every rule lives.
Projects, not random folders, are the compilation boundary. Internal types stay internal.
Contracts
Public methods say whether a value can be null. Do not silence the nullable warning with ! unless you just checked. A union or a closed hierarchy is appropriate on a TFM that has C# 15. On an older TFM, use the pattern the codebase already uses. Do not paste preview syntax into a .NET 10 build.
Validate input at the endpoint with the project's validator. The validated type is what the handler accepts.
Async
Async methods take a CancellationToken and pass it on. Do not use async void except for an event handler the platform requires. Do not block on a task with .Result or .Wait(). A timeout is a CancellationTokenSource linked to the caller's token, not a discarded task.
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 · 106 lines · 0 tokens per session scan A 19a182854090
dotnet-rules is a cursor rule published in the GitHub repository beel-collab/presets.dev (3 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,070 tokens. 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 2026-11-13.
dotnet-rules compared with cursor rules from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| dotnet-rulesbeel-collab/presets.dev | Cursor rule | 3 | yesterday | MIT | A | 0 | Cursor |
| ponytailDietrichGebert/ponytail | Cursor rule | 190k | 15d ago | MIT | A | 604 | Cursor |
| angular-20angular/angular | Cursor rule | 101k | today | MIT | A | 0 | Cursor |
| dev-standardapache/superset | Cursor rule | 76k | today | Apache-2.0 | A | 1,147 | Cursor |
| prefer-direct-imports-over-module-mocksprisma/orm | Cursor rule | 48k | today | Apache-2.0 | A | 0 | Cursor |
| config-validation-and-normalizationprisma/orm | Cursor rule | 48k | today | Apache-2.0 | A | 0 | Cursor |
| control-plane-descriptorsprisma/orm | Cursor rule | 48k | today | Apache-2.0 | A | 0 | Cursor |