How do I install the Perf Hotpath Guard skill?

Run npx skillmds@latest add abbaye/perf-hotpath-guard in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Perf Hotpath Guard safe to use?

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Which AI agents work with Perf Hotpath Guard?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Perf Hotpath Guard free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Perf Hotpath Guard?

abbaye (@abbaye) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Perf Hotpath Guard by abbaye — Agent Skill

Name: Perf Hotpath Guard
Author: abbaye

Perf Hotpath Guard

INTERNAL DEV WORKFLOW for WpfHexEditor — Claude self-invokes after editing C# in render/layout/scroll hot paths (HexEditor/, CodeEditor/Rendering*, *Viewport*, *GlyphRun*, *Renderer*, *ScrollHandler*, OnRender, MeasureOverride, ArrangeOverride) to detect allocations and patterns that cause jank or GC pressure. Skip on: tests, mocks, designer files, non-render code in non-hot directories.

abbaye af1c0f7 4 files · 12.9 KB Updated Sep 17, 2026

File contents

perf-hotpath-guard (internal)

Catches perf anti-patterns from project history (jank, GC pressure in render loops). Memory anchors: adr_006_zoom_rendering, adr_hexeditor_viewport_race, bug_drag_scroll_fix, feedback_wordwrap_column, bug_doc_editor_caret_hittest.

When I invoke

Trigger: .cs edits matching ANY of:

Path under HexEditor/ or CodeEditor/Rendering
Filename contains Viewport, GlyphRun, Renderer, ScrollHandler
Edit modifies OnRender, MeasureOverride, or ArrangeOverride

Skip if path contains Test, Mock, *.Designer.cs, *.g.cs, *.g.i.cs.

Pipeline

scripts/hotpath-scan.ps1 -Files <paths> (applies rules inside hot-method bodies only) → HotPath: <n> issues or OK.

9 rules

See references/perf-rules.md for regex + rationale.

Rule	Anchor
`alloc-in-render`	GC pressure/jank
`linq-in-hot`	allocations + delegate creation
`string-concat-loop`	O(n²) allocations
`boxing`	struct→object passing
`dispatcher-cosmetic`	`feedback_wordwrap_column` anti-pattern
`formatted-text-recreate`	`bug_doc_editor_caret_hittest`
`glyph-run-recreate`	render cost without pool
`findvisualchild-render`	O(n) tree walk every frame
`regex-in-render`	compile cost on hot path

Hot methods (from references/hot-methods.md): OnRender, MeasureOverride, ArrangeOverride, OnPreviewMouseMove, OnScrollChanged, Render*/Draw*/Paint* in renderer files, any method preceded by // HOT. Exclude with // COLD.

Output

HotPath: 2 issues
  HexLineRenderer.cs:142  alloc-in-render         OnRender -> new SolidColorBrush(...)
  TextViewport.cs:88      formatted-text-recreate OnRender -> new FormattedText(...)

Suppress: // alloc-ok: <reason> (alloc-in-render), // COLD (exclude method), // HOT-EXCEPTION: <note> (document legitimate exception). Static analysis only — no runtime profiling, no code rewrite.

---name: perf-hotpath-guarddescription: INTERNAL DEV WORKFLOW for WpfHexEditor — Claude self-invokes after editing C# in render/layout/scroll hot paths (HexEditor/, CodeEditor/Rendering*, *Viewport*, *GlyphRun*, *Renderer*, *ScrollHandler*, OnRender, MeasureOverride, ArrangeOverride) to detect allocations and patterns that cause jank or GC pressure. Skip on: tests, mocks, designer files, non-render code in non-hot directories.---# perf-hotpath-guard (internal)Catches perf anti-patterns from project history (jank, GC pressure in render loops). Memory anchors: `adr_006_zoom_rendering`, `adr_hexeditor_viewport_race`, `bug_drag_scroll_fix`, `feedback_wordwrap_column`, `bug_doc_editor_caret_hittest`.## When I invokeTrigger: `.cs` edits matching ANY of:- Path under `HexEditor/` or `CodeEditor/Rendering`- Filename contains `Viewport`, `GlyphRun`, `Renderer`, `ScrollHandler`- Edit modifies `OnRender`, `MeasureOverride`, or `ArrangeOverride`Skip if path contains `Test`, `Mock`, `*.Designer.cs`, `*.g.cs`, `*.g.i.cs`.## Pipeline`scripts/hotpath-scan.ps1 -Files <paths>` (applies rules inside hot-method bodies only) → `HotPath: <n> issues` or `OK`.## 9 rulesSee `references/perf-rules.md` for regex + rationale.| Rule | Anchor ||---|---|| `alloc-in-render` | GC pressure/jank || `linq-in-hot` | allocations + delegate creation || `string-concat-loop` | O(n²) allocations || `boxing` | struct→object passing || `dispatcher-cosmetic` | `feedback_wordwrap_column` anti-pattern || `formatted-text-recreate` | `bug_doc_editor_caret_hittest` || `glyph-run-recreate` | render cost without pool || `findvisualchild-render` | O(n) tree walk every frame || `regex-in-render` | compile cost on hot path |**Hot methods** (from `references/hot-methods.md`): `OnRender`, `MeasureOverride`, `ArrangeOverride`, `OnPreviewMouseMove`, `OnScrollChanged`, `Render*`/`Draw*`/`Paint*` in renderer files, any method preceded by `// HOT`. Exclude with `// COLD`.## Output```HotPath: 2 issues HexLineRenderer.cs:142 alloc-in-render OnRender -> new SolidColorBrush(...) TextViewport.cs:88 formatted-text-recreate OnRender -> new FormattedText(...)```Suppress: `// alloc-ok: <reason>` (alloc-in-render), `// COLD` (exclude method), `// HOT-EXCEPTION: <note>` (document legitimate exception).Static analysis only — no runtime profiling, no code rewrite.

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