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+# GitHub Copilot Instructions
+
+This file is read automatically by GitHub Copilot.
+
+## For Complete AI Assistant Instructions
+
+See the **aitools** repository for comprehensive AI assistant guidance:
+
+### Main Instructions
+- **AI Assistant Instructions**: `aitools/ai-instructions.md`
+
+### Detailed Skills and Procedures
+
+When you need specific guidance on workflows and tools, consult the appropriate file in `aitools/skills/`:
+
+- **Offline build procedures**: `aitools/skills/offline-instructions.md`
+- **Muse build system**: `aitools/skills/muse-reference.md`
+- **Smack/Spack reference**: `aitools/skills/smack-reference.md`
+- Additional skill files as they are added
+
+---
+
+**Key points for this workspace:**
+- This is the Mu2e offline software ecosystem (simulation, reconstruction, analysis)
+- Build using the **Muse** system, never run `cmake` directly
+- Changes may affect multiple coordinated repositories (Offline, Production, mu2e-trig-config)
+- See aitools repository for complete procedures and reference materials
+