diff --git a/extension/src/shared/types.ts b/extension/src/shared/types.ts
index e2b7340..7893e38 100644
--- a/extension/src/shared/types.ts
+++ b/extension/src/shared/types.ts
@@ -183,15 +183,24 @@ export interface ManifestEntry {
   attachment_summaries: AttachmentSummary[];
 }
 
-// --- Vault settings (only the fields α touches) ---
+// --- Vault settings ---
 // Full shape lives on the Rust side and in docs/superpowers/specs/2026-04-18-relicario-typed-items-design.md
-// We leave retention/generator/caps opaque to α so we don't accidentally mutate them.
+// β₂ tightens retention + generator_defaults; γ owns attachment_caps.
+
+export type TrashRetention =
+  | { kind: 'forever' }
+  | { kind: 'days'; value: number };
+
+export type HistoryRetention =
+  | { kind: 'forever' }
+  | { kind: 'last_n'; value: number }
+  | { kind: 'days'; value: number };
 
 export interface VaultSettings {
-  trash_retention: unknown;
-  field_history_retention: unknown;
-  generator_defaults: unknown;
-  attachment_caps: unknown;
+  trash_retention: TrashRetention;
+  field_history_retention: HistoryRetention;
+  generator_defaults: GeneratorRequest;
+  attachment_caps: unknown;                 // opaque — γ tightens
   autofill_origin_acks: Record<string, number>;
 }