diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index c768825..9e3e6c1 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -53,6 +53,14 @@ You are operating in a multi-repo, documentation-first architecture. You MUST ST
 > For detailed docs see: `README.md` → `docs/`
 > External repos in `own-dep-repos` are fully accessible — read their source code, docs, and `.github/copilot-instructions.md` freely when you need type definitions, base classes, or context. Do not limit yourself to the current workspace.
 
+## Shared Agent Skills
+
+Skills defined in other repos that can be referenced from here:
+
+- **protocol-audit** — Cross-repo consistency audit for `.github/copilot-instructions.md` across all 5 repos.
+  Location: `AyCode.Core/.github/skills/protocol-audit/SKILL.md`
+  Activate from an AyCode.Core session, or read the SKILL.md directly and follow its steps.
+
 ## DevExpress Components
 1. **DevExpress Blazor 25.1.3** — always use `DxGrid`, `DxFormLayout`, etc. Do NOT mix with generic Blazor component libraries.
 2. **Grid system** uses `AcSignalRDataSource` for real-time data — grids fetch data via SignalR, not REST.