diff --git a/CLAUDE.md b/CLAUDE.md
index c17b1178..ef93d9fe 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -167,6 +167,16 @@ hive-ag3nt/        in-container harness crate; produces TWO binaries
                          fell outside the truncation window in a
                          trailing `mentions (truncated from body):`
                          block (#539 / #544).
+  src/identity.rs       hive-qualified agent label (#589 phase A):
+                         `label()` / `hive_domain()` /
+                         `qualified_label()` / `qualify(label)`. Reads
+                         `HYPERHIVE_HIVE_DOMAIN` env var (set from
+                         `hyperhive.domain` by the c0re module); when
+                         unset or empty, `qualified_label` degrades to
+                         the short name so single-hive deployments are
+                         unchanged. Drives `{qualified_label}` prompt
+                         substitution, browser tab title, and
+                         `/api/state.qualified_label`.
   src/login.rs          probe /root/.claude/ for a valid session
   src/login_session.rs  drives `claude auth login` over stdio pipes
   src/prompt.rs         system prompt renderer: filters the unified