diff --git a/CLAUDE.md b/CLAUDE.md
index 0979c95e..769756f6 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -94,6 +94,18 @@ Rules:
 - **Express conditionals as English.** Instead of nested `if/elif/else` in bash,
   write numbered decision steps: "1. If X, do Y. 2. Otherwise, do Z."
 
+## Platform-agnostic design
+
+Skills must NEVER hardcode framework-specific commands, file patterns, or directory
+structures. Instead:
+
+1. **Read CLAUDE.md** for project-specific config (test commands, eval commands, etc.)
+2. **If missing, AskUserQuestion** — let the user tell you or let gstack search the repo
+3. **Persist the answer to CLAUDE.md** so we never have to ask again
+
+This applies to test commands, eval commands, deploy commands, and any other
+project-specific behavior. The project owns its config; gstack reads it.
+
 ## Browser interaction
 
 When you need to interact with a browser (QA, dogfooding, cookie setup), use the