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.
npx skills add managedcode/dotnet-skills --skill dotnet-pinvokegit clone --depth 1 https://github.com/managedcode/dotnet-skillsWrote 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/dotnet-pinvoke)<a href="https://agentmods.dev/skills/managedcode/dotnet-skills/dotnet-pinvoke"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/dotnet-pinvoke/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/dotnet-pinvoke"><img src="https://agentmods.dev/badge/skills/managedcode/dotnet-skills/dotnet-pinvoke.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 | $0.00119 | $0.04759 |
| Opus 5.5 | $0.00048 | $0.01904 |
| Sonnet 5.5 | $0.00024 | $0.00952 |
| Haiku 4.5 | $0.00012 | $0.00476 |
Grade A, and why
dotnet-pinvoke 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 3d 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.
This is a copy
100% identical to dotnet-pinvoke — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 452 lines — stays where its author put it; the contents beside it link to each section on GitHub.
.NET P/Invoke
Calling native code from .NET is powerful but unforgiving. Incorrect signatures, garbled strings, and leaked or freed memory are the most common sources of bugs — all can manifest as intermittent crashes, silent data corruption, or access violations far from the actual defect.
This skill covers both DllImport (available since .NET Framework 1.0) and LibraryImport (source-generated, .NET 7+). When targeting .NET Framework, always use DllImport. When targeting .NET 7+, prefer LibraryImport for new code. When native AOT is a requirement, LibraryImport is the only option.
When to Use This Skill
- Writing a new
[DllImport]or[LibraryImport]declaration from a C/C++ header - Reviewing P/Invoke signatures for correctness (type sizes, calling conventions, string encoding)
- Wrapping an entire C library for use from .NET
- Debugging
AccessViolationException,DllNotFoundException, or silent data corruption at the native boundary - Migrating
DllImportdeclarations toLibraryImportfor AOT/trimming compatibility - Diagnosing memory leaks or heap corruption involving native handles or buffers
Stop Signals
- Single function? Map the signature (Steps 1-3), handle strings/memory only if relevant, skip tooling and migration sections.
- Don't migrate existing
DllImporttoLibraryImportunless the user asks or AOT/trimming is an explicit requirement. - Don't recommend CsWin32 unless the target is specifically Win32 APIs.
- Don't generate callbacks (Step 8) unless the native API requires function pointers.
- Review request? Use the validation checklist — don't rewrite working code.
Inputs
| Input | Required | Description |
|---|---|---|
| Native header or documentation | Yes | C/C++ function signatures, struct definitions, calling conventions |
| Target framework | Yes | Determines whether to use DllImport or LibraryImport |
| Target platforms | Recommended | Affects type sizes (long, size_t) and library naming |
| Memory ownership contract | Yes | Who allocates and who frees each buffer or handle |
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.
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.
- 3d ago Changed · +2 lines 05f8fe734ec6
- 1mo ago First seen · 450 lines · 119 tokens per session scan A 40dd8410a9eb
dotnet-pinvoke is a skill published in the GitHub repository managedcode/dotnet-skills (493 stars, last pushed yesterday), licensed MIT. It adds 119 tokens to every session and 4,759 once invoked, about $0.0005 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to dotnet-pinvoke, differing in 0 lines, and is treated as a copy.
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