diff --git a/src/lib/api.ts b/src/lib/api.ts
index 5da4ffa..0774bb4 100644
--- a/src/lib/api.ts
+++ b/src/lib/api.ts
@@ -186,3 +186,67 @@ export interface Transaction {
   createdAt: string;
   updatedAt: string;
 }
+
+export interface Decision {
+  id: string;
+  tenantId: string;
+  ownerUserId: string;
+  context: string;
+  options: unknown[];
+  assumptions: unknown[];
+  evidence: unknown[];
+  selectedOption: string | null;
+  outcomeReview: string | null;
+  reviewDueAt: string | null;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export type NotificationSeverity =
+  | 'CRITICAL'
+  | 'ACTION_REQUIRED'
+  | 'WARNING'
+  | 'INFORMATION'
+  | 'INTELLIGENCE'
+  | 'SYSTEM';
+
+export type NotificationStatus =
+  | 'PENDING'
+  | 'SCHEDULED'
+  | 'DELIVERING'
+  | 'DELIVERED'
+  | 'READ'
+  | 'ACKNOWLEDGED'
+  | 'DISMISSED'
+  | 'FAILED'
+  | 'EXPIRED'
+  | 'ESCALATED';
+
+export interface Notification {
+  id: string;
+  tenantId: string;
+  recipientUserId: string;
+  category: string;
+  severity: NotificationSeverity;
+  title: string;
+  body: string | null;
+  sourceEntityType: string | null;
+  sourceEntityId: string | null;
+  actionUrl: string | null;
+  status: NotificationStatus;
+  aggregatedCount: number;
+  readAt: string | null;
+  createdAt: string;
+}
+
+export interface AuditLogEntry {
+  id: string;
+  tenantId: string;
+  actorType: string;
+  actorId: string | null;
+  action: string;
+  resource: string;
+  reason: string | null;
+  correlationId: string | null;
+  createdAt: string;
+}