diff --git a/AGENTS.md b/AGENTS.md
index 90d6ed7be..6cb251b1c 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -261,6 +261,7 @@ After adjusting the source string, you need to call the respective translation l
 - Go: golangci-lint per `.golangci.yml`; use goimports; wrap errors with `fmt.Errorf("...: %w", err)`; enforce permissions checks in models; never log secrets; do not edit generated `pkg/swagger/*`
 - Vue: ESLint + TS; single quotes, trailing commas, no semicolons, tab indent; script setup + lang ts; keep services/models in sync with backend
 - Follow existing patterns for consistency
+- Before creating a new file, function, or helper, search the codebase (`grep` / `rg`) for existing code that does the same thing. Prefer extending an existing helper over duplicating it. If logic overlaps an existing function significantly, reuse it.
 
 **Naming Conventions:**
 - Go: Standard Go conventions (PascalCase for exports, camelCase for private)