diff --git a/src/auth/auth.service.ts b/src/auth/auth.service.ts
index 7df0cb8..3039cec 100644
--- a/src/auth/auth.service.ts
+++ b/src/auth/auth.service.ts
@@ -1205,6 +1205,10 @@ export class AuthService {
     });
   }
 
+  /**
+   * Generate a new API key value with 'pc_' prefix and 24 random characters.
+   * Format: pc_<24-char-random-hex>
+   */
   private generateApiKeyValue() {
     return `pc_${randomToken(24)}`;
   }
diff --git a/src/auth/guards/rate-limit.guard.ts b/src/auth/guards/rate-limit.guard.ts
index ce5d740..5a16725 100644
--- a/src/auth/guards/rate-limit.guard.ts
+++ b/src/auth/guards/rate-limit.guard.ts
@@ -53,6 +53,8 @@ export class RateLimitGuard implements CanActivate {
 
     try {
       // Check by user if authenticated
+      // Tier defaults to 'free' as it is not included in the current JWT payload.
+      // When 'tier' is added to JwtPayload, this logic will use the actual value.
       if (request.user?.id) {
         const userTier = request.user.tier || 'free';
         const userStatus = await this.rateLimitService.checkUserRateLimit(
diff --git a/src/common/common.types.ts b/src/common/common.types.ts
index 65fba43..55f4008 100644
--- a/src/common/common.types.ts
+++ b/src/common/common.types.ts
@@ -8,6 +8,11 @@ import {
   TransactionStatus,
   DocumentType,
   VerificationStatus,
+  FraudSeverity,
+  FraudStatus,
+  FraudPattern,
+  DisputeStatus,
+  MilestoneStatus,
 } from '@prisma/client';
 
 registerEnumType(UserRole, { name: 'UserRole' });
@@ -16,6 +21,11 @@ registerEnumType(TransactionType, { name: 'TransactionType' });
 registerEnumType(TransactionStatus, { name: 'TransactionStatus' });
 registerEnumType(DocumentType, { name: 'DocumentType' });
 registerEnumType(VerificationStatus, { name: 'VerificationStatus' });
+registerEnumType(FraudSeverity, { name: 'FraudSeverity' });
+registerEnumType(FraudStatus, { name: 'FraudStatus' });
+registerEnumType(FraudPattern, { name: 'FraudPattern' });
+registerEnumType(DisputeStatus, { name: 'DisputeStatus' });
+registerEnumType(MilestoneStatus, { name: 'MilestoneStatus' });
 
 export {
   UserRole,
@@ -24,4 +34,9 @@ export {
   TransactionStatus,
   DocumentType,
   VerificationStatus,
+  FraudSeverity,
+  FraudStatus,
+  FraudPattern,
+  DisputeStatus,
+  MilestoneStatus,
 };