diff --git a/openspec/specs/staging-environment/spec.md b/openspec/specs/staging-environment/spec.md
index 5d9541e..7cfd58e 100644
--- a/openspec/specs/staging-environment/spec.md
+++ b/openspec/specs/staging-environment/spec.md
@@ -1,3 +1,7 @@
+## Purpose
+
+Production-like staging and ephemeral PR preview environments running alongside production on the flagship server, enabling integration testing before merge and live URL sharing with reviewers.
+
 ## Requirements
 
 ### Requirement: Persistent staging instance