Index: src/services/guardianship/context.js
===================================================================
--- src/services/guardianship/context.js	(revision 6b5d7da762e4f4cedbefb24fb218a1006897f071)
+++ src/services/guardianship/context.js	(revision 6b5d7da762e4f4cedbefb24fb218a1006897f071)
@@ -0,0 +1,26 @@
+/**
+ * Guardianship (FEP-633c "Guardians") — JSON-LD vocabulary.
+ *
+ * One source of truth for the shaer namespace and the terms Klonkt emits.
+ * ActivityPubService spreads SHAER_CONTEXT into its AP_CONTEXT term block, so
+ * every outgoing document declares the namespace and strict JSON-LD
+ * processors resolve the terms instead of dropping them.
+ */
+
+/** The term block merged into AP_CONTEXT. */
+export const SHAER_CONTEXT = {
+  // FEP-633c (Guardians): the shaer namespace. helpRequest marks a direct
+  // note as a ward's call for help (spec 5.2.1); ignorable by everyone else.
+  shaer: 'https://ns.klonkt.com/shaer#',
+};
+
+/** The Relationship value in the adoption Offer (FEP-633c §3), both forms. */
+export const GUARDIAN_RELATIONSHIP = 'https://ns.klonkt.com/shaer#Guardian';
+export const GUARDIAN_RELATIONSHIP_COMPACT = 'shaer:Guardian';
+
+/** True when an Offer's relationship names the guardian relation. */
+export function isGuardianRelationship(value) {
+  return value === GUARDIAN_RELATIONSHIP || value === GUARDIAN_RELATIONSHIP_COMPACT;
+}
+
+export default { SHAER_CONTEXT, GUARDIAN_RELATIONSHIP, GUARDIAN_RELATIONSHIP_COMPACT, isGuardianRelationship };