diff --git a/frontends/nextjs/src/app/api/dbal/schema/route.ts b/frontends/nextjs/src/app/api/dbal/schema/route.ts
index da41b49dd..3424da801 100644
--- a/frontends/nextjs/src/app/api/dbal/schema/route.ts
+++ b/frontends/nextjs/src/app/api/dbal/schema/route.ts
@@ -182,7 +182,7 @@ function handleApprove(registry: SchemaRegistry, registryPath: string, id?: stri
 }
 
 function handleReject(registry: SchemaRegistry, registryPath: string, id?: string) {
-  if (!id) {
+  if (id === null || id === undefined || id === '') {
     return NextResponse.json(
       { status: 'error', error: 'Migration ID required' },
       { status: 400 }
diff --git a/frontends/nextjs/src/app/api/github/actions/runs/[runId]/logs/route.ts b/frontends/nextjs/src/app/api/github/actions/runs/[runId]/logs/route.ts
index afe19d493..1df3b84d2 100644
--- a/frontends/nextjs/src/app/api/github/actions/runs/[runId]/logs/route.ts
+++ b/frontends/nextjs/src/app/api/github/actions/runs/[runId]/logs/route.ts
@@ -48,7 +48,7 @@ export const GET = async (request: NextRequest, { params }: RouteParams) => {
     })
   } catch (error) {
     const status =
-      typeof error === 'object' && error && 'status' in error
+      typeof error === 'object' && error !== null && 'status' in error
         ? Number((error as { status?: number }).status)
         : 500
     const message = error instanceof Error ? error.message : 'Unknown error'
diff --git a/frontends/nextjs/src/app/api/github/actions/runs/route.ts b/frontends/nextjs/src/app/api/github/actions/runs/route.ts
index c59d0c18b..25134615b 100644
--- a/frontends/nextjs/src/app/api/github/actions/runs/route.ts
+++ b/frontends/nextjs/src/app/api/github/actions/runs/route.ts
@@ -30,7 +30,7 @@ export const GET = async (request: NextRequest) => {
     })
   } catch (error) {
     const status =
-      typeof error === 'object' && error && 'status' in error
+      typeof error === 'object' && error !== null && 'status' in error
         ? Number((error as { status?: number }).status)
         : 500
     const message = error instanceof Error ? error.message : 'Unknown error'
diff --git a/frontends/nextjs/src/app/api/v1/[...slug]/route.ts b/frontends/nextjs/src/app/api/v1/[...slug]/route.ts
index 347de8dc6..4dcc80ec6 100644
--- a/frontends/nextjs/src/app/api/v1/[...slug]/route.ts
+++ b/frontends/nextjs/src/app/api/v1/[...slug]/route.ts
@@ -81,7 +81,7 @@ async function handleRequest(
     if (['POST', 'PUT', 'PATCH'].includes(request.method)) {
       try {
         const text = await request.text()
-        if (text) {
+        if (text !== null && text !== undefined && text !== '') {
           body = JSON.parse(text)
         }
       } catch {
@@ -124,18 +124,18 @@ async function handleRequest(
 
     if (!result.success) {
       // Map common errors to appropriate status codes
-      const errorMsg = result.error || 'Operation failed'
-      if (errorMsg.includes('not found')) {
+      const errorMsg = result.error ?? 'Operation failed'
+      if (errorMsg !== null && errorMsg !== undefined && errorMsg.includes('not found')) {
         return errorResponse(errorMsg, STATUS.NOT_FOUND)
       }
-      if (errorMsg.includes('required')) {
+      if (errorMsg !== null && errorMsg !== undefined && errorMsg.includes('required')) {
         return errorResponse(errorMsg, STATUS.BAD_REQUEST)
       }
       return errorResponse(errorMsg, STATUS.INTERNAL_ERROR)
     }
 
     // Build response with metadata
-    const responseData = result.meta 
+    const responseData = result.meta !== null && result.meta !== undefined
       ? { data: result.data, ...(result.meta as Record<string, unknown>) }
       : result.data
 
diff --git a/frontends/nextjs/src/app/page.tsx b/frontends/nextjs/src/app/page.tsx
index beaae4630..07d0bb83c 100644
--- a/frontends/nextjs/src/app/page.tsx
+++ b/frontends/nextjs/src/app/page.tsx
@@ -62,7 +62,7 @@ export default async function RootPage() {
       const pkg = await loadJSONPackage(`/home/rewrich/Documents/GitHub/metabuilder/packages/${route.packageId}`)
       const component = pkg?.components?.find(c => c.id === route.component || c.name === route.component)
 
-      if (component) {
+      if (component !== null && component !== undefined) {
         return renderJSONComponent(component, {}, {})
       }
     }
diff --git a/frontends/nextjs/src/lib/db/packages/data/get/get-package-data.ts b/frontends/nextjs/src/lib/db/packages/data/get/get-package-data.ts
index 3a8779ce4..3219a2e70 100644
--- a/frontends/nextjs/src/lib/db/packages/data/get/get-package-data.ts
+++ b/frontends/nextjs/src/lib/db/packages/data/get/get-package-data.ts
@@ -9,6 +9,6 @@ export async function getPackageData(packageId: string): Promise<PackageSeedData
   const pkg = (await adapter.findFirst('PackageData', {
     where: { packageId },
   })) as { data: string } | null
-  if (!pkg) return {}
+  if (pkg === null || pkg === undefined) return {}
   return JSON.parse(pkg.data) as PackageSeedData
 }
diff --git a/frontends/nextjs/src/lib/db/packages/install/crud/install-package.ts b/frontends/nextjs/src/lib/db/packages/install/crud/install-package.ts
index 0ad077a33..f15d786e5 100644
--- a/frontends/nextjs/src/lib/db/packages/install/crud/install-package.ts
+++ b/frontends/nextjs/src/lib/db/packages/install/crud/install-package.ts
@@ -9,7 +9,7 @@ export async function installPackage(packageData: InstalledPackage): Promise<voi
   const existing = await adapter.findFirst('InstalledPackage', {
     where: { packageId: packageData.packageId },
   })
-  if (!existing) {
+  if (existing === null || existing === undefined) {
     await adapter.create('InstalledPackage', {
       packageId: packageData.packageId,
       installedAt: BigInt(packageData.installedAt),
diff --git a/frontends/nextjs/src/lib/db/pages/crud/get-pages.ts b/frontends/nextjs/src/lib/db/pages/crud/get-pages.ts
index 946e5878b..65ad6e81e 100644
--- a/frontends/nextjs/src/lib/db/pages/crud/get-pages.ts
+++ b/frontends/nextjs/src/lib/db/pages/crud/get-pages.ts
@@ -37,6 +37,6 @@ export async function getPages(): Promise<PageConfig[]> {
     level: Number(p.level) as PageConfig['level'],
     componentTree: JSON.parse(p.componentTree) as PageConfig['componentTree'],
     requiresAuth: p.requiresAuth,
-    requiredRole: p.requiredRole ? toUserRole(p.requiredRole) : undefined,
+    requiredRole: p.requiredRole !== null && p.requiredRole !== undefined ? toUserRole(p.requiredRole) : undefined,
   }))
 }
diff --git a/frontends/nextjs/src/lib/db/schemas/crud/add-schema.ts b/frontends/nextjs/src/lib/db/schemas/crud/add-schema.ts
index 7371f7a57..5b15df9fd 100644
--- a/frontends/nextjs/src/lib/db/schemas/crud/add-schema.ts
+++ b/frontends/nextjs/src/lib/db/schemas/crud/add-schema.ts
@@ -12,9 +12,9 @@ export async function addSchema(schema: ModelSchema): Promise<void> {
     labelPlural: schema.labelPlural,
     icon: schema.icon,
     fields: JSON.stringify(schema.fields),
-    listDisplay: schema.listDisplay ? JSON.stringify(schema.listDisplay) : null,
-    listFilter: schema.listFilter ? JSON.stringify(schema.listFilter) : null,
-    searchFields: schema.searchFields ? JSON.stringify(schema.searchFields) : null,
-    ordering: schema.ordering ? JSON.stringify(schema.ordering) : null,
+    listDisplay: schema.listDisplay !== null && schema.listDisplay !== undefined ? JSON.stringify(schema.listDisplay) : null,
+    listFilter: schema.listFilter !== null && schema.listFilter !== undefined ? JSON.stringify(schema.listFilter) : null,
+    searchFields: schema.searchFields !== null && schema.searchFields !== undefined ? JSON.stringify(schema.searchFields) : null,
+    ordering: schema.ordering !== null && schema.ordering !== undefined ? JSON.stringify(schema.ordering) : null,
   })
 }