Borrowing it
Nothing to install: this file belongs to vchelaru/XnaFiddle. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/vchelaru/XnaFiddle/main/.claude/skills/share-snippet/SKILL.mdgit clone --depth 1 https://github.com/vchelaru/XnaFiddleWrote 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/vchelaru/xnafiddle/share-snippet)<a href="https://agentmods.dev/skills/vchelaru/xnafiddle/share-snippet"><img src="https://agentmods.dev/badge/skills/vchelaru/xnafiddle/share-snippet/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/vchelaru/xnafiddle/share-snippet"><img src="https://agentmods.dev/badge/skills/vchelaru/xnafiddle/share-snippet.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 | $0.00043 | $0.01115 |
| Opus 5 | $0.00022 | $0.00558 |
| Sonnet 5 | $0.00009 | $0.00223 |
| Haiku 4.5 | $0.00004 | $0.00112 |
Grade A, and why
share-snippet 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 47 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Share / Snippet round-trip
Three ways to share a fiddle. They differ in fidelity — this is the part that bites.
| Mode | URL | Fidelity |
|---|---|---|
Code (ShareAsCode) |
#code=<source> |
Lossless — stores the editor source verbatim |
| Snippet | #snippet=<model> |
Lossy by design — round-trips through SnippetReverter -> SnippetModel -> SnippetExpander; only scaffold-shaped content survives |
| Gist | external | Partial; see the shaders skill |
Shaders travel in all three. That is the shaders skill's territory — point there, don't re-document.
The fidelity contract (the snippet codec)
SnippetExpander and SnippetReverter are exact inverses around a fixed scaffold (a FiddleGame : Game skeleton). Only what fits a SnippetModel field survives the trip; anything the scaffold can't represent is dropped. The codec is symmetric: every line the expander injects is a line the reverter must strip, or sharing-then-resharing bloats.
- Scaffold-owned boilerplate. The expander owns the constructor and a
GraphicsDeviceManager graphics;field, plus the canonical method-body lines (base.Initialize/Update/Draw,GraphicsDevice.Clear(...)). The reverter strips exactly these back out (InjectedMembersset + theIsInjected*statement predicates). Keep the two sides in lockstep when editing either. - Constructor handoff (issue #83 — the crux). A custom constructor used to be dropped outright. Now
SnippetModel.Constructorcarries it: when present, the expander steps aside — emits neither its owngraphicsfield nor the default ctor and reproduces the user's verbatim. The reverter captures the ctor body only when it differs from the canonical scaffold ctor (IsScaffoldConstructor, compared on whitespace-collapsed text), so scaffold-shaped snippets stay compact. Subtlety: once a custom ctor is captured, a user field literally namedgraphicsmust be kept rather than mistaken for the injected one. - Presets are inferred from
usingdirectives.IsGum/IsAposShapes/IsMonoGameExtendedare detected on revert from the namespaces present (not stored explicitly), and each injects its members + method-body lines on expand / is stripped on revert. The flag set drives which injected lines the reverter recognizes.
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.
- 4d ago First seen · 47 lines · 43 tokens per session scan A aea0dfa38b72
share-snippet is a skill published in the GitHub repository vchelaru/XnaFiddle (13 stars, last pushed 3d ago), licensed MIT. It adds 43 tokens to every session and 1,115 once invoked, about $0.0002 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 2026-09-04.
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