diff --git a/Dockerfile b/Dockerfile
index 3faec82..dcbc76a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -29,7 +29,9 @@ RUN npx prisma generate
 
 COPY --from=builder /app/build ./build
 COPY --from=builder /app/server.js ./server.js
+COPY scripts ./scripts
 
+RUN apk add --no-cache postgresql-client
 RUN apk del python3 make g++ && rm -rf /var/cache/apk/*
 RUN mkdir -p /app/uploads
 
diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index 6aa61bc..90ac540 100644
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -20,5 +20,12 @@ if [ $RETRY -ge $MAX_RETRIES ]; then
   exit 1
 fi
 
+echo "Applying RLS policies..."
+if psql "$DATABASE_URL" -f ./scripts/setup-rls.sql; then
+  echo "RLS policies applied successfully."
+else
+  echo "WARNING: Failed to apply RLS policies. Continuing anyway..."
+fi
+
 echo "Starting server..."
 exec node server.js
diff --git a/scripts/setup-rls.sql b/scripts/setup-rls.sql
index f3a8eff..c5d5678 100644
--- a/scripts/setup-rls.sql
+++ b/scripts/setup-rls.sql
@@ -1,65 +1,144 @@
 -- Row-Level Security (RLS) Policies
 -- Run this after migrations to enable tenant isolation at the DB level.
+-- Idempotent: safe to re-run on every deploy.
 
--- Helper: current tenant context (set via SET LOCAL in Prisma extension)
--- Usage: SET LOCAL app.current_tenant_id = '<uuid>';
+-- Helper: current tenant context (set via set_config() in Prisma transaction)
+-- Usage: SELECT set_config('app.current_tenant_id', '<uuid>', true);
 
--- ─── Enable RLS ──────────────────────────────────────────
+-- ─── Tables WITHOUT RLS (cross-tenant by design) ──────
+ALTER TABLE tenants DISABLE ROW LEVEL SECURITY;
+ALTER TABLE tenant_hostnames DISABLE ROW LEVEL SECURITY;
+ALTER TABLE sessions DISABLE ROW LEVEL SECURITY;
+
+-- ─── Enable + Force RLS ────────────────────────────────
 
 ALTER TABLE users ENABLE ROW LEVEL SECURITY;
-ALTER TABLE boards ENABLE ROW LEVEL SECURITY;
-ALTER TABLE board_members ENABLE ROW LEVEL SECURITY;
-ALTER TABLE columns ENABLE ROW LEVEL SECURITY;
-ALTER TABLE cards ENABLE ROW LEVEL SECURITY;
-ALTER TABLE card_assignees ENABLE ROW LEVEL SECURITY;
-ALTER TABLE tags ENABLE ROW LEVEL SECURITY;
-ALTER TABLE card_labels ENABLE ROW LEVEL SECURITY;
-ALTER TABLE categories ENABLE ROW LEVEL SECURITY;
-ALTER TABLE checklists ENABLE ROW LEVEL SECURITY;
-ALTER TABLE checklist_items ENABLE ROW LEVEL SECURITY;
-ALTER TABLE comments ENABLE ROW LEVEL SECURITY;
-ALTER TABLE attachments ENABLE ROW LEVEL SECURITY;
-ALTER TABLE activities ENABLE ROW LEVEL SECURITY;
-ALTER TABLE notifications ENABLE ROW LEVEL SECURITY;
-ALTER TABLE board_templates ENABLE ROW LEVEL SECURITY;
+ALTER TABLE users FORCE ROW LEVEL SECURITY;
 
--- ─── Tenant-scoped tables (direct tenant_id) ────────────
+ALTER TABLE boards ENABLE ROW LEVEL SECURITY;
+ALTER TABLE boards FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE board_members ENABLE ROW LEVEL SECURITY;
+ALTER TABLE board_members FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE columns ENABLE ROW LEVEL SECURITY;
+ALTER TABLE columns FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE cards ENABLE ROW LEVEL SECURITY;
+ALTER TABLE cards FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE card_assignees ENABLE ROW LEVEL SECURITY;
+ALTER TABLE card_assignees FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE tags ENABLE ROW LEVEL SECURITY;
+ALTER TABLE tags FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE card_labels ENABLE ROW LEVEL SECURITY;
+ALTER TABLE card_labels FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE categories ENABLE ROW LEVEL SECURITY;
+ALTER TABLE categories FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE checklists ENABLE ROW LEVEL SECURITY;
+ALTER TABLE checklists FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE checklist_items ENABLE ROW LEVEL SECURITY;
+ALTER TABLE checklist_items FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE comments ENABLE ROW LEVEL SECURITY;
+ALTER TABLE comments FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE attachments ENABLE ROW LEVEL SECURITY;
+ALTER TABLE attachments FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE activities ENABLE ROW LEVEL SECURITY;
+ALTER TABLE activities FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE notifications ENABLE ROW LEVEL SECURITY;
+ALTER TABLE notifications FORCE ROW LEVEL SECURITY;
+
+ALTER TABLE board_templates ENABLE ROW LEVEL SECURITY;
+ALTER TABLE board_templates FORCE ROW LEVEL SECURITY;
+
+-- ─── Tenant-scoped tables (direct tenant_id) ──────────
 
 -- Users
 DROP POLICY IF EXISTS users_tenant_isolation ON users;
 CREATE POLICY users_tenant_isolation ON users
-  USING (tenant_id::text = current_setting('app.current_tenant_id', true));
+  USING (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  );
 
 -- Boards
 DROP POLICY IF EXISTS boards_tenant_isolation ON boards;
 CREATE POLICY boards_tenant_isolation ON boards
-  USING (tenant_id::text = current_setting('app.current_tenant_id', true));
+  USING (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  );
 
 -- Tags
 DROP POLICY IF EXISTS tags_tenant_isolation ON tags;
 CREATE POLICY tags_tenant_isolation ON tags
-  USING (tenant_id::text = current_setting('app.current_tenant_id', true));
+  USING (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  );
 
 -- Categories
 DROP POLICY IF EXISTS categories_tenant_isolation ON categories;
 CREATE POLICY categories_tenant_isolation ON categories
-  USING (tenant_id::text = current_setting('app.current_tenant_id', true));
+  USING (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  );
 
 -- Board Templates (null tenant_id = system template, visible to all)
 DROP POLICY IF EXISTS board_templates_tenant_isolation ON board_templates;
 CREATE POLICY board_templates_tenant_isolation ON board_templates
   USING (
-    tenant_id IS NULL
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id IS NULL
+    OR tenant_id::text = current_setting('app.current_tenant_id', true)
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR tenant_id IS NULL
     OR tenant_id::text = current_setting('app.current_tenant_id', true)
   );
 
--- ─── Board-scoped tables (via join to boards) ───────────
+-- ─── Board-scoped tables (via join to boards) ─────────
 
 -- Board Members
 DROP POLICY IF EXISTS board_members_tenant_isolation ON board_members;
 CREATE POLICY board_members_tenant_isolation ON board_members
   USING (
-    board_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR board_id IN (
+      SELECT id FROM boards
+      WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR board_id IN (
       SELECT id FROM boards
       WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
     )
@@ -69,7 +148,15 @@ CREATE POLICY board_members_tenant_isolation ON board_members
 DROP POLICY IF EXISTS columns_tenant_isolation ON columns;
 CREATE POLICY columns_tenant_isolation ON columns
   USING (
-    board_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR board_id IN (
+      SELECT id FROM boards
+      WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR board_id IN (
       SELECT id FROM boards
       WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
     )
@@ -79,7 +166,15 @@ CREATE POLICY columns_tenant_isolation ON columns
 DROP POLICY IF EXISTS activities_tenant_isolation ON activities;
 CREATE POLICY activities_tenant_isolation ON activities
   USING (
-    board_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR board_id IN (
+      SELECT id FROM boards
+      WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR board_id IN (
       SELECT id FROM boards
       WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
     )
@@ -91,7 +186,16 @@ CREATE POLICY activities_tenant_isolation ON activities
 DROP POLICY IF EXISTS cards_tenant_isolation ON cards;
 CREATE POLICY cards_tenant_isolation ON cards
   USING (
-    column_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR column_id IN (
+      SELECT c.id FROM columns c
+      JOIN boards b ON c.board_id = b.id
+      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR column_id IN (
       SELECT c.id FROM columns c
       JOIN boards b ON c.board_id = b.id
       WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
@@ -102,7 +206,17 @@ CREATE POLICY cards_tenant_isolation ON cards
 DROP POLICY IF EXISTS card_assignees_tenant_isolation ON card_assignees;
 CREATE POLICY card_assignees_tenant_isolation ON card_assignees
   USING (
-    card_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
+      SELECT ca.id FROM cards ca
+      JOIN columns c ON ca.column_id = c.id
+      JOIN boards b ON c.board_id = b.id
+      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
       SELECT ca.id FROM cards ca
       JOIN columns c ON ca.column_id = c.id
       JOIN boards b ON c.board_id = b.id
@@ -114,7 +228,17 @@ CREATE POLICY card_assignees_tenant_isolation ON card_assignees
 DROP POLICY IF EXISTS card_labels_tenant_isolation ON card_labels;
 CREATE POLICY card_labels_tenant_isolation ON card_labels
   USING (
-    card_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
+      SELECT ca.id FROM cards ca
+      JOIN columns c ON ca.column_id = c.id
+      JOIN boards b ON c.board_id = b.id
+      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
       SELECT ca.id FROM cards ca
       JOIN columns c ON ca.column_id = c.id
       JOIN boards b ON c.board_id = b.id
@@ -126,7 +250,17 @@ CREATE POLICY card_labels_tenant_isolation ON card_labels
 DROP POLICY IF EXISTS checklists_tenant_isolation ON checklists;
 CREATE POLICY checklists_tenant_isolation ON checklists
   USING (
-    card_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
+      SELECT ca.id FROM cards ca
+      JOIN columns c ON ca.column_id = c.id
+      JOIN boards b ON c.board_id = b.id
+      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
       SELECT ca.id FROM cards ca
       JOIN columns c ON ca.column_id = c.id
       JOIN boards b ON c.board_id = b.id
@@ -138,7 +272,18 @@ CREATE POLICY checklists_tenant_isolation ON checklists
 DROP POLICY IF EXISTS checklist_items_tenant_isolation ON checklist_items;
 CREATE POLICY checklist_items_tenant_isolation ON checklist_items
   USING (
-    checklist_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR checklist_id IN (
+      SELECT ch.id FROM checklists ch
+      JOIN cards ca ON ch.card_id = ca.id
+      JOIN columns c ON ca.column_id = c.id
+      JOIN boards b ON c.board_id = b.id
+      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR checklist_id IN (
       SELECT ch.id FROM checklists ch
       JOIN cards ca ON ch.card_id = ca.id
       JOIN columns c ON ca.column_id = c.id
@@ -151,7 +296,17 @@ CREATE POLICY checklist_items_tenant_isolation ON checklist_items
 DROP POLICY IF EXISTS comments_tenant_isolation ON comments;
 CREATE POLICY comments_tenant_isolation ON comments
   USING (
-    card_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
+      SELECT ca.id FROM cards ca
+      JOIN columns c ON ca.column_id = c.id
+      JOIN boards b ON c.board_id = b.id
+      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
       SELECT ca.id FROM cards ca
       JOIN columns c ON ca.column_id = c.id
       JOIN boards b ON c.board_id = b.id
@@ -163,7 +318,17 @@ CREATE POLICY comments_tenant_isolation ON comments
 DROP POLICY IF EXISTS attachments_tenant_isolation ON attachments;
 CREATE POLICY attachments_tenant_isolation ON attachments
   USING (
-    card_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
+      SELECT ca.id FROM cards ca
+      JOIN columns c ON ca.column_id = c.id
+      JOIN boards b ON c.board_id = b.id
+      WHERE b.tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR card_id IN (
       SELECT ca.id FROM cards ca
       JOIN columns c ON ca.column_id = c.id
       JOIN boards b ON c.board_id = b.id
@@ -171,17 +336,22 @@ CREATE POLICY attachments_tenant_isolation ON attachments
     )
   );
 
--- ─── User-scoped tables ─────────────────────────────────
+-- ─── User-scoped tables ───────────────────────────────
 
 -- Notifications
 DROP POLICY IF EXISTS notifications_tenant_isolation ON notifications;
 CREATE POLICY notifications_tenant_isolation ON notifications
   USING (
-    user_id IN (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR user_id IN (
+      SELECT id FROM users
+      WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
+    )
+  )
+  WITH CHECK (
+    current_setting('app.current_tenant_id', true) = '__bypass__'
+    OR user_id IN (
       SELECT id FROM users
       WHERE tenant_id::text = current_setting('app.current_tenant_id', true)
     )
   );
-
--- Sessions (no RLS - cross-tenant by design for session validation)
--- Sessions are validated in application code with tenant check
diff --git a/src/lib/server/auth.ts b/src/lib/server/auth.ts
index 125a36b..0740118 100644
--- a/src/lib/server/auth.ts
+++ b/src/lib/server/auth.ts
@@ -1,5 +1,6 @@
 import bcrypt from 'bcrypt';
 import { prisma } from './db.js';
+import { withBypassRLS } from './rls.js';
 
 const SALT_ROUNDS = 12;
 const SESSION_DURATION_MS = 30 * 24 * 60 * 60 * 1000; // 30 days
@@ -21,30 +22,34 @@ export async function createSession(userId: string): Promise<{ id: string; expir
 }
 
 export async function validateSession(sessionId: string) {
-	const session = await prisma.session.findUnique({
-		where: { id: sessionId },
-		include: {
-			user: {
-				select: {
-					id: true,
-					email: true,
-					name: true,
-					globalRole: true,
-					tenantRole: true,
-					tenantId: true
+	// Uses withBypassRLS because this joins to the users table (RLS-protected)
+	// and runs before tenant context is established in hooks.server.ts.
+	return withBypassRLS(async (tx) => {
+		const session = await tx.session.findUnique({
+			where: { id: sessionId },
+			include: {
+				user: {
+					select: {
+						id: true,
+						email: true,
+						name: true,
+						globalRole: true,
+						tenantRole: true,
+						tenantId: true
+					}
 				}
 			}
+		});
+
+		if (!session) return null;
+
+		if (session.expiresAt < new Date()) {
+			await tx.session.delete({ where: { id: sessionId } });
+			return null;
 		}
+
+		return session;
 	});
-
-	if (!session) return null;
-
-	if (session.expiresAt < new Date()) {
-		await prisma.session.delete({ where: { id: sessionId } });
-		return null;
-	}
-
-	return session;
 }
 
 export async function deleteSession(sessionId: string) {
diff --git a/src/lib/server/rls.ts b/src/lib/server/rls.ts
index 8a4b79a..3c18461 100644
--- a/src/lib/server/rls.ts
+++ b/src/lib/server/rls.ts
@@ -1,56 +1,36 @@
-import { PrismaClient } from '@prisma/client';
+import type { Prisma } from '@prisma/client';
+import { prisma } from './db.js';
+
+type TxClient = Prisma.TransactionClient;
 
 /**
- * Prisma client extension for Row-Level Security.
+ * Executes a callback within an interactive Prisma transaction
+ * with the RLS tenant context set to the given tenantId.
  *
- * Usage:
- *   const db = forTenant(tenantId);
- *   const boards = await db.board.findMany(); // automatically filtered
- *
- *   const db = bypassRLS();
- *   const allBoards = await db.board.findMany(); // no RLS
+ * All queries inside the callback are scoped to that tenant
+ * by PostgreSQL RLS policies.
  */
-
-const basePrisma = new PrismaClient();
-
-/**
- * Returns a Prisma client that sets the tenant context for RLS policies.
- * All queries through this client will be filtered to the specified tenant.
- */
-export function forTenant(tenantId: string): PrismaClient {
-	return basePrisma.$extends({
-		query: {
-			$allOperations({ args, query }) {
-				return basePrisma.$transaction(async (tx) => {
-					await tx.$executeRawUnsafe(
-						`SET LOCAL app.current_tenant_id = '${tenantId}'`
-					);
-					return query(args);
-				});
-			}
-		}
-	}) as unknown as PrismaClient;
+export async function withTenant<T>(
+	tenantId: string,
+	callback: (tx: TxClient) => Promise<T>
+): Promise<T> {
+	return prisma.$transaction(async (tx) => {
+		await tx.$executeRaw`SELECT set_config('app.current_tenant_id', ${tenantId}, true)`;
+		return callback(tx);
+	});
 }
 
 /**
- * Returns a Prisma client that bypasses RLS.
- * Use for Site Admin operations that need cross-tenant access.
+ * Executes a callback that bypasses RLS.
+ * Uses the '__bypass__' sentinel recognized by RLS policies.
+ *
+ * Use for cross-tenant operations like session validation.
  */
-export function bypassRLS(): PrismaClient {
-	return basePrisma.$extends({
-		query: {
-			$allOperations({ args, query }) {
-				return basePrisma.$transaction(async (tx) => {
-					await tx.$executeRawUnsafe(
-						`SET LOCAL app.current_tenant_id = ''`
-					);
-					// With RLS, setting an empty tenant_id effectively shows nothing.
-					// For bypass, we need to use a superuser or disable RLS.
-					// In practice, the app Prisma client (db.ts) doesn't enable RLS
-					// on the connection, so this is used when RLS is fully enabled.
-					return query(args);
-				});
-			}
-		}
-	}) as unknown as PrismaClient;
+export async function withBypassRLS<T>(
+	callback: (tx: TxClient) => Promise<T>
+): Promise<T> {
+	return prisma.$transaction(async (tx) => {
+		await tx.$executeRaw`SELECT set_config('app.current_tenant_id', ${'__bypass__'}, true)`;
+		return callback(tx);
+	});
 }
diff --git a/src/routes/api/auth/login/+server.ts b/src/routes/api/auth/login/+server.ts
index 94edd15..0ffd4ec 100644
--- a/src/routes/api/auth/login/+server.ts
+++ b/src/routes/api/auth/login/+server.ts
@@ -1,8 +1,8 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types.js';
-import { prisma } from '$lib/server/db.js';
 import { verifyPassword, createSession, sessionCookieName, sessionCookieOptions } from '$lib/server/auth.js';
 import { loginSchema } from '$lib/server/validation.js';
+import { withTenant } from '$lib/server/rls.js';
 
 export const POST: RequestHandler = async ({ request, locals, cookies }) => {
 	const tenant = locals.tenant;
@@ -16,13 +16,17 @@ export const POST: RequestHandler = async ({ request, locals, cookies }) => {
 
 	const { email, password } = result.data;
 
-	const user = await prisma.user.findUnique({
-		where: { tenantId_email: { tenantId: tenant.id, email } }
+	const user = await withTenant(tenant.id, async (tx) => {
+		return tx.user.findUnique({
+			where: { tenantId_email: { tenantId: tenant.id, email } }
+		});
 	});
+
 	if (!user) {
 		return json({ error: 'Invalid email or password' }, { status: 401 });
 	}
 
+	// Verify password outside transaction
 	const valid = await verifyPassword(password, user.passwordHash);
 	if (!valid) {
 		return json({ error: 'Invalid email or password' }, { status: 401 });
diff --git a/src/routes/api/auth/register/+server.ts b/src/routes/api/auth/register/+server.ts
index 293ec8e..3f816d4 100644
--- a/src/routes/api/auth/register/+server.ts
+++ b/src/routes/api/auth/register/+server.ts
@@ -1,8 +1,8 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types.js';
-import { prisma } from '$lib/server/db.js';
 import { hashPassword, createSession, sessionCookieName, sessionCookieOptions } from '$lib/server/auth.js';
 import { registerSchema } from '$lib/server/validation.js';
+import { withTenant } from '$lib/server/rls.js';
 
 export const POST: RequestHandler = async ({ request, locals, cookies }) => {
 	const tenant = locals.tenant;
@@ -16,24 +16,32 @@ export const POST: RequestHandler = async ({ request, locals, cookies }) => {
 
 	const { email, name, password } = result.data;
 
-	// Check if user already exists in this tenant
-	const existing = await prisma.user.findUnique({
-		where: { tenantId_email: { tenantId: tenant.id, email } }
+	// Hash password outside transaction to avoid holding DB connection during bcrypt
+	const passwordHash = await hashPassword(password);
+
+	const user = await withTenant(tenant.id, async (tx) => {
+		// Check if user already exists in this tenant
+		const existing = await tx.user.findUnique({
+			where: { tenantId_email: { tenantId: tenant.id, email } }
+		});
+		if (existing) {
+			return null;
+		}
+
+		return tx.user.create({
+			data: {
+				tenantId: tenant.id,
+				email,
+				name,
+				passwordHash
+			}
+		});
 	});
-	if (existing) {
+
+	if (!user) {
 		return json({ error: 'An account with this email already exists' }, { status: 409 });
 	}
 
-	const passwordHash = await hashPassword(password);
-	const user = await prisma.user.create({
-		data: {
-			tenantId: tenant.id,
-			email,
-			name,
-			passwordHash
-		}
-	});
-
 	const session = await createSession(user.id);
 	cookies.set(sessionCookieName(), session.id, sessionCookieOptions(session.expiresAt));
 
diff --git a/src/routes/api/boards/+server.ts b/src/routes/api/boards/+server.ts
index 0cab7f0..4373e86 100644
--- a/src/routes/api/boards/+server.ts
+++ b/src/routes/api/boards/+server.ts
@@ -1,36 +1,37 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types.js';
-import { prisma } from '$lib/server/db.js';
 import { boardSchema } from '$lib/server/validation.js';
+import { withTenant } from '$lib/server/rls.js';
 
 // List boards for current tenant
 export const GET: RequestHandler = async ({ locals }) => {
 	const tenant = locals.tenant;
 	if (!tenant) throw error(400, 'Unknown tenant');
 
-	const where: Record<string, unknown> = { tenantId: tenant.id, archived: false };
+	const boards = await withTenant(tenant.id, async (tx) => {
+		const where: Record<string, unknown> = { tenantId: tenant.id, archived: false };
 
-	// If not logged in, only show public boards
-	if (!locals.user) {
-		where.visibility = 'PUBLIC';
-	} else {
-		// Show boards user is a member of + public boards
-		where.OR = [
-			{ visibility: 'PUBLIC' },
-			{ members: { some: { userId: locals.user.id } } }
-		];
-		delete where.visibility;
-	}
+		// If not logged in, only show public boards
+		if (!locals.user) {
+			where.visibility = 'PUBLIC';
+		} else {
+			// Show boards user is a member of + public boards
+			where.OR = [
+				{ visibility: 'PUBLIC' },
+				{ members: { some: { userId: locals.user.id } } }
+			];
+		}
 
-	const boards = await prisma.board.findMany({
-		where,
-		include: {
-			members: {
-				include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+		return tx.board.findMany({
+			where,
+			include: {
+				members: {
+					include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+				},
+				_count: { select: { columns: true } }
 			},
-			_count: { select: { columns: true } }
-		},
-		orderBy: { updatedAt: 'desc' }
+			orderBy: { updatedAt: 'desc' }
+		});
 	});
 
 	return json({ boards });
@@ -50,24 +51,26 @@ export const POST: RequestHandler = async ({ request, locals }) => {
 
 	const { title, description, visibility } = result.data;
 
-	const board = await prisma.board.create({
-		data: {
-			tenantId: tenant.id,
-			title,
-			description,
-			visibility,
-			members: {
-				create: {
-					userId: locals.user.id,
-					role: 'OWNER'
+	const board = await withTenant(tenant.id, async (tx) => {
+		return tx.board.create({
+			data: {
+				tenantId: tenant.id,
+				title,
+				description,
+				visibility,
+				members: {
+					create: {
+						userId: locals.user!.id,
+						role: 'OWNER'
+					}
+				}
+			},
+			include: {
+				members: {
+					include: { user: { select: { id: true, name: true, avatarUrl: true } } }
 				}
 			}
-		},
-		include: {
-			members: {
-				include: { user: { select: { id: true, name: true, avatarUrl: true } } }
-			}
-		}
+		});
 	});
 
 	return json({ board }, { status: 201 });
diff --git a/src/routes/api/boards/[boardId]/+server.ts b/src/routes/api/boards/[boardId]/+server.ts
index 1d5efad..a09d66d 100644
--- a/src/routes/api/boards/[boardId]/+server.ts
+++ b/src/routes/api/boards/[boardId]/+server.ts
@@ -1,36 +1,38 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types.js';
-import { prisma } from '$lib/server/db.js';
 import { boardSchema } from '$lib/server/validation.js';
+import { withTenant } from '$lib/server/rls.js';
 
 // Get single board with all columns and cards
 export const GET: RequestHandler = async ({ params, locals }) => {
 	const tenant = locals.tenant;
 	if (!tenant) throw error(400, 'Unknown tenant');
 
-	const board = await prisma.board.findFirst({
-		where: { id: params.boardId, tenantId: tenant.id },
-		include: {
-			columns: {
-				orderBy: { position: 'asc' },
-				include: {
-					cards: {
-						where: { archived: false },
-						orderBy: { position: 'asc' },
-						include: {
-							assignees: {
-								include: { user: { select: { id: true, name: true, avatarUrl: true } } }
-							},
-							labels: { include: { tag: true } },
-							_count: { select: { comments: true, checklists: true, attachments: true } }
+	const board = await withTenant(tenant.id, async (tx) => {
+		return tx.board.findFirst({
+			where: { id: params.boardId, tenantId: tenant.id },
+			include: {
+				columns: {
+					orderBy: { position: 'asc' },
+					include: {
+						cards: {
+							where: { archived: false },
+							orderBy: { position: 'asc' },
+							include: {
+								assignees: {
+									include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+								},
+								labels: { include: { tag: true } },
+								_count: { select: { comments: true, checklists: true, attachments: true } }
+							}
 						}
 					}
+				},
+				members: {
+					include: { user: { select: { id: true, name: true, email: true, avatarUrl: true } } }
 				}
-			},
-			members: {
-				include: { user: { select: { id: true, name: true, email: true, avatarUrl: true } } }
 			}
-		}
+		});
 	});
 
 	if (!board) throw error(404, 'Board not found');
@@ -53,27 +55,29 @@ export const PATCH: RequestHandler = async ({ params, request, locals }) => {
 	if (!tenant) throw error(400, 'Unknown tenant');
 	if (!locals.user) throw error(401, 'Not authenticated');
 
-	const board = await prisma.board.findFirst({
-		where: { id: params.boardId, tenantId: tenant.id },
-		include: { members: true }
-	});
-	if (!board) throw error(404, 'Board not found');
-
-	const member = board.members.find((m) => m.userId === locals.user!.id);
-	const isAdmin =
-		locals.user.globalRole === 'SITE_ADMIN' || locals.user.tenantRole === 'ADMIN';
-	if (!member && !isAdmin) throw error(403, 'Access denied');
-	if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot edit boards');
-
 	const body = await request.json();
 	const result = boardSchema.partial().safeParse(body);
 	if (!result.success) {
 		return json({ error: result.error.issues[0].message }, { status: 400 });
 	}
 
-	const updated = await prisma.board.update({
-		where: { id: params.boardId },
-		data: result.data
+	const updated = await withTenant(tenant.id, async (tx) => {
+		const board = await tx.board.findFirst({
+			where: { id: params.boardId, tenantId: tenant.id },
+			include: { members: true }
+		});
+		if (!board) throw error(404, 'Board not found');
+
+		const member = board.members.find((m) => m.userId === locals.user!.id);
+		const isAdmin =
+			locals.user!.globalRole === 'SITE_ADMIN' || locals.user!.tenantRole === 'ADMIN';
+		if (!member && !isAdmin) throw error(403, 'Access denied');
+		if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot edit boards');
+
+		return tx.board.update({
+			where: { id: params.boardId },
+			data: result.data
+		});
 	});
 
 	return json({ board: updated });
@@ -85,18 +89,20 @@ export const DELETE: RequestHandler = async ({ params, locals }) => {
 	if (!tenant) throw error(400, 'Unknown tenant');
 	if (!locals.user) throw error(401, 'Not authenticated');
 
-	const board = await prisma.board.findFirst({
-		where: { id: params.boardId, tenantId: tenant.id },
-		include: { members: true }
+	await withTenant(tenant.id, async (tx) => {
+		const board = await tx.board.findFirst({
+			where: { id: params.boardId, tenantId: tenant.id },
+			include: { members: true }
+		});
+		if (!board) throw error(404, 'Board not found');
+
+		const member = board.members.find((m) => m.userId === locals.user!.id);
+		const isAdmin =
+			locals.user!.globalRole === 'SITE_ADMIN' || locals.user!.tenantRole === 'ADMIN';
+		if (member?.role !== 'OWNER' && !isAdmin) throw error(403, 'Only owners can delete boards');
+
+		await tx.board.delete({ where: { id: params.boardId } });
 	});
-	if (!board) throw error(404, 'Board not found');
-
-	const member = board.members.find((m) => m.userId === locals.user!.id);
-	const isAdmin =
-		locals.user.globalRole === 'SITE_ADMIN' || locals.user.tenantRole === 'ADMIN';
-	if (member?.role !== 'OWNER' && !isAdmin) throw error(403, 'Only owners can delete boards');
-
-	await prisma.board.delete({ where: { id: params.boardId } });
 
 	return json({ ok: true });
 };
diff --git a/src/routes/api/boards/[boardId]/columns/+server.ts b/src/routes/api/boards/[boardId]/columns/+server.ts
index 8c06b2f..84112aa 100644
--- a/src/routes/api/boards/[boardId]/columns/+server.ts
+++ b/src/routes/api/boards/[boardId]/columns/+server.ts
@@ -1,8 +1,8 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types.js';
-import { prisma } from '$lib/server/db.js';
 import { columnSchema } from '$lib/server/validation.js';
 import { generatePosition } from '$lib/utils/fractional-index.js';
+import { withTenant } from '$lib/server/rls.js';
 
 // Create column
 export const POST: RequestHandler = async ({ params, request, locals }) => {
@@ -10,40 +10,42 @@ export const POST: RequestHandler = async ({ params, request, locals }) => {
 	if (!tenant) throw error(400, 'Unknown tenant');
 	if (!locals.user) throw error(401, 'Not authenticated');
 
-	const board = await prisma.board.findFirst({
-		where: { id: params.boardId, tenantId: tenant.id },
-		include: { members: true }
-	});
-	if (!board) throw error(404, 'Board not found');
-
-	const member = board.members.find((m) => m.userId === locals.user!.id);
-	const isAdmin = locals.user.globalRole === 'SITE_ADMIN' || locals.user.tenantRole === 'ADMIN';
-	if (!member && !isAdmin) throw error(403, 'Access denied');
-	if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot add columns');
-
 	const body = await request.json();
 	const result = columnSchema.safeParse(body);
 	if (!result.success) {
 		return json({ error: result.error.issues[0].message }, { status: 400 });
 	}
 
-	// Get the last column position
-	const lastColumn = await prisma.column.findFirst({
-		where: { boardId: params.boardId },
-		orderBy: { position: 'desc' }
-	});
+	const column = await withTenant(tenant.id, async (tx) => {
+		const board = await tx.board.findFirst({
+			where: { id: params.boardId, tenantId: tenant.id },
+			include: { members: true }
+		});
+		if (!board) throw error(404, 'Board not found');
 
-	const position = generatePosition(lastColumn?.position, null);
+		const member = board.members.find((m) => m.userId === locals.user!.id);
+		const isAdmin = locals.user!.globalRole === 'SITE_ADMIN' || locals.user!.tenantRole === 'ADMIN';
+		if (!member && !isAdmin) throw error(403, 'Access denied');
+		if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot add columns');
 
-	const column = await prisma.column.create({
-		data: {
-			boardId: params.boardId,
-			title: result.data.title,
-			position
-		},
-		include: {
-			cards: true
-		}
+		// Get the last column position
+		const lastColumn = await tx.column.findFirst({
+			where: { boardId: params.boardId },
+			orderBy: { position: 'desc' }
+		});
+
+		const position = generatePosition(lastColumn?.position, null);
+
+		return tx.column.create({
+			data: {
+				boardId: params.boardId,
+				title: result.data.title,
+				position
+			},
+			include: {
+				cards: true
+			}
+		});
 	});
 
 	return json({ column }, { status: 201 });
diff --git a/src/routes/api/boards/[boardId]/columns/[columnId]/+server.ts b/src/routes/api/boards/[boardId]/columns/[columnId]/+server.ts
index 310a5f9..ad752f7 100644
--- a/src/routes/api/boards/[boardId]/columns/[columnId]/+server.ts
+++ b/src/routes/api/boards/[boardId]/columns/[columnId]/+server.ts
@@ -1,7 +1,7 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types.js';
-import { prisma } from '$lib/server/db.js';
 import { columnSchema, moveColumnSchema } from '$lib/server/validation.js';
+import { withTenant } from '$lib/server/rls.js';
 
 // Update column title
 export const PATCH: RequestHandler = async ({ params, request, locals }) => {
@@ -9,40 +9,41 @@ export const PATCH: RequestHandler = async ({ params, request, locals }) => {
 	if (!tenant) throw error(400, 'Unknown tenant');
 	if (!locals.user) throw error(401, 'Not authenticated');
 
-	const column = await prisma.column.findFirst({
-		where: { id: params.columnId, board: { id: params.boardId, tenantId: tenant.id } },
-		include: { board: { include: { members: true } } }
-	});
-	if (!column) throw error(404, 'Column not found');
-
-	const member = column.board.members.find((m) => m.userId === locals.user!.id);
-	const isAdmin = locals.user.globalRole === 'SITE_ADMIN' || locals.user.tenantRole === 'ADMIN';
-	if (!member && !isAdmin) throw error(403, 'Access denied');
-	if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot edit columns');
-
 	const body = await request.json();
 
-	// Allow both title update and position update
-	if (body.position !== undefined) {
-		const result = moveColumnSchema.safeParse(body);
-		if (!result.success) {
-			return json({ error: result.error.issues[0].message }, { status: 400 });
-		}
-		const updated = await prisma.column.update({
-			where: { id: params.columnId },
-			data: { position: result.data.position }
+	const updated = await withTenant(tenant.id, async (tx) => {
+		const column = await tx.column.findFirst({
+			where: { id: params.columnId, board: { id: params.boardId, tenantId: tenant.id } },
+			include: { board: { include: { members: true } } }
 		});
-		return json({ column: updated });
-	}
+		if (!column) throw error(404, 'Column not found');
 
-	const result = columnSchema.safeParse(body);
-	if (!result.success) {
-		return json({ error: result.error.issues[0].message }, { status: 400 });
-	}
+		const member = column.board.members.find((m) => m.userId === locals.user!.id);
+		const isAdmin = locals.user!.globalRole === 'SITE_ADMIN' || locals.user!.tenantRole === 'ADMIN';
+		if (!member && !isAdmin) throw error(403, 'Access denied');
+		if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot edit columns');
 
-	const updated = await prisma.column.update({
-		where: { id: params.columnId },
-		data: { title: result.data.title }
+		// Allow both title update and position update
+		if (body.position !== undefined) {
+			const result = moveColumnSchema.safeParse(body);
+			if (!result.success) {
+				throw error(400, result.error.issues[0].message);
+			}
+			return tx.column.update({
+				where: { id: params.columnId },
+				data: { position: result.data.position }
+			});
+		}
+
+		const result = columnSchema.safeParse(body);
+		if (!result.success) {
+			throw error(400, result.error.issues[0].message);
+		}
+
+		return tx.column.update({
+			where: { id: params.columnId },
+			data: { title: result.data.title }
+		});
 	});
 
 	return json({ column: updated });
@@ -54,18 +55,20 @@ export const DELETE: RequestHandler = async ({ params, locals }) => {
 	if (!tenant) throw error(400, 'Unknown tenant');
 	if (!locals.user) throw error(401, 'Not authenticated');
 
-	const column = await prisma.column.findFirst({
-		where: { id: params.columnId, board: { id: params.boardId, tenantId: tenant.id } },
-		include: { board: { include: { members: true } } }
+	await withTenant(tenant.id, async (tx) => {
+		const column = await tx.column.findFirst({
+			where: { id: params.columnId, board: { id: params.boardId, tenantId: tenant.id } },
+			include: { board: { include: { members: true } } }
+		});
+		if (!column) throw error(404, 'Column not found');
+
+		const member = column.board.members.find((m) => m.userId === locals.user!.id);
+		const isAdmin = locals.user!.globalRole === 'SITE_ADMIN' || locals.user!.tenantRole === 'ADMIN';
+		if (member?.role === 'VIEWER' && !isAdmin) throw error(403, 'Viewers cannot delete columns');
+		if (!member && !isAdmin) throw error(403, 'Access denied');
+
+		await tx.column.delete({ where: { id: params.columnId } });
 	});
-	if (!column) throw error(404, 'Column not found');
-
-	const member = column.board.members.find((m) => m.userId === locals.user!.id);
-	const isAdmin = locals.user.globalRole === 'SITE_ADMIN' || locals.user.tenantRole === 'ADMIN';
-	if (member?.role === 'VIEWER' && !isAdmin) throw error(403, 'Viewers cannot delete columns');
-	if (!member && !isAdmin) throw error(403, 'Access denied');
-
-	await prisma.column.delete({ where: { id: params.columnId } });
 
 	return json({ ok: true });
 };
diff --git a/src/routes/api/boards/[boardId]/columns/[columnId]/cards/+server.ts b/src/routes/api/boards/[boardId]/columns/[columnId]/cards/+server.ts
index b81f902..14114f4 100644
--- a/src/routes/api/boards/[boardId]/columns/[columnId]/cards/+server.ts
+++ b/src/routes/api/boards/[boardId]/columns/[columnId]/cards/+server.ts
@@ -1,8 +1,8 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types.js';
-import { prisma } from '$lib/server/db.js';
 import { cardSchema } from '$lib/server/validation.js';
 import { generatePosition } from '$lib/utils/fractional-index.js';
+import { withTenant } from '$lib/server/rls.js';
 
 // Create card in column
 export const POST: RequestHandler = async ({ params, request, locals }) => {
@@ -10,45 +10,47 @@ export const POST: RequestHandler = async ({ params, request, locals }) => {
 	if (!tenant) throw error(400, 'Unknown tenant');
 	if (!locals.user) throw error(401, 'Not authenticated');
 
-	const column = await prisma.column.findFirst({
-		where: { id: params.columnId, board: { id: params.boardId, tenantId: tenant.id } },
-		include: { board: { include: { members: true } } }
-	});
-	if (!column) throw error(404, 'Column not found');
-
-	const member = column.board.members.find((m) => m.userId === locals.user!.id);
-	const isAdmin = locals.user.globalRole === 'SITE_ADMIN' || locals.user.tenantRole === 'ADMIN';
-	if (!member && !isAdmin) throw error(403, 'Access denied');
-	if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot add cards');
-
 	const body = await request.json();
 	const result = cardSchema.safeParse(body);
 	if (!result.success) {
 		return json({ error: result.error.issues[0].message }, { status: 400 });
 	}
 
-	// Get the last card position in this column
-	const lastCard = await prisma.card.findFirst({
-		where: { columnId: params.columnId },
-		orderBy: { position: 'desc' }
-	});
+	const card = await withTenant(tenant.id, async (tx) => {
+		const column = await tx.column.findFirst({
+			where: { id: params.columnId, board: { id: params.boardId, tenantId: tenant.id } },
+			include: { board: { include: { members: true } } }
+		});
+		if (!column) throw error(404, 'Column not found');
 
-	const position = generatePosition(lastCard?.position, null);
+		const member = column.board.members.find((m) => m.userId === locals.user!.id);
+		const isAdmin = locals.user!.globalRole === 'SITE_ADMIN' || locals.user!.tenantRole === 'ADMIN';
+		if (!member && !isAdmin) throw error(403, 'Access denied');
+		if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot add cards');
 
-	const card = await prisma.card.create({
-		data: {
-			columnId: params.columnId,
-			title: result.data.title,
-			description: result.data.description,
-			position
-		},
-		include: {
-			assignees: {
-				include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+		// Get the last card position in this column
+		const lastCard = await tx.card.findFirst({
+			where: { columnId: params.columnId },
+			orderBy: { position: 'desc' }
+		});
+
+		const position = generatePosition(lastCard?.position, null);
+
+		return tx.card.create({
+			data: {
+				columnId: params.columnId,
+				title: result.data.title,
+				description: result.data.description,
+				position
 			},
-			labels: { include: { tag: true } },
-			_count: { select: { comments: true, checklists: true, attachments: true } }
-		}
+			include: {
+				assignees: {
+					include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+				},
+				labels: { include: { tag: true } },
+				_count: { select: { comments: true, checklists: true, attachments: true } }
+			}
+		});
 	});
 
 	return json({ card }, { status: 201 });
diff --git a/src/routes/api/boards/[boardId]/columns/[columnId]/cards/[cardId]/+server.ts b/src/routes/api/boards/[boardId]/columns/[columnId]/cards/[cardId]/+server.ts
index c513f2a..ae7716f 100644
--- a/src/routes/api/boards/[boardId]/columns/[columnId]/cards/[cardId]/+server.ts
+++ b/src/routes/api/boards/[boardId]/columns/[columnId]/cards/[cardId]/+server.ts
@@ -1,34 +1,36 @@
 import { json, error } from '@sveltejs/kit';
 import type { RequestHandler } from './$types.js';
-import { prisma } from '$lib/server/db.js';
 import { cardSchema, moveCardSchema } from '$lib/server/validation.js';
+import { withTenant } from '$lib/server/rls.js';
 
 // Get single card with full details
 export const GET: RequestHandler = async ({ params, locals }) => {
 	const tenant = locals.tenant;
 	if (!tenant) throw error(400, 'Unknown tenant');
 
-	const card = await prisma.card.findFirst({
-		where: {
-			id: params.cardId,
-			column: { id: params.columnId, board: { id: params.boardId, tenantId: tenant.id } }
-		},
-		include: {
-			assignees: {
-				include: { user: { select: { id: true, name: true, email: true, avatarUrl: true } } }
+	const card = await withTenant(tenant.id, async (tx) => {
+		return tx.card.findFirst({
+			where: {
+				id: params.cardId,
+				column: { id: params.columnId, board: { id: params.boardId, tenantId: tenant.id } }
 			},
-			labels: { include: { tag: true } },
-			checklists: {
-				orderBy: { position: 'asc' },
-				include: { items: { orderBy: { position: 'asc' } } }
-			},
-			comments: {
-				orderBy: { createdAt: 'desc' },
-				include: { user: { select: { id: true, name: true, avatarUrl: true } } }
-			},
-			attachments: { orderBy: { createdAt: 'desc' } },
-			column: { select: { id: true, title: true } }
-		}
+			include: {
+				assignees: {
+					include: { user: { select: { id: true, name: true, email: true, avatarUrl: true } } }
+				},
+				labels: { include: { tag: true } },
+				checklists: {
+					orderBy: { position: 'asc' },
+					include: { items: { orderBy: { position: 'asc' } } }
+				},
+				comments: {
+					orderBy: { createdAt: 'desc' },
+					include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+				},
+				attachments: { orderBy: { createdAt: 'desc' } },
+				column: { select: { id: true, title: true } }
+			}
+		});
 	});
 
 	if (!card) throw error(404, 'Card not found');
@@ -42,31 +44,55 @@ export const PATCH: RequestHandler = async ({ params, request, locals }) => {
 	if (!tenant) throw error(400, 'Unknown tenant');
 	if (!locals.user) throw error(401, 'Not authenticated');
 
-	const card = await prisma.card.findFirst({
-		where: {
-			id: params.cardId,
-			column: { board: { id: params.boardId, tenantId: tenant.id } }
-		},
-		include: { column: { include: { board: { include: { members: true } } } } }
-	});
-	if (!card) throw error(404, 'Card not found');
-
-	const member = card.column.board.members.find((m) => m.userId === locals.user!.id);
-	const isAdmin = locals.user.globalRole === 'SITE_ADMIN' || locals.user.tenantRole === 'ADMIN';
-	if (!member && !isAdmin) throw error(403, 'Access denied');
-	if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot edit cards');
-
 	const body = await request.json();
 
-	// Handle move (column change + position)
-	if (body.columnId !== undefined || body.position !== undefined) {
-		const data: Record<string, unknown> = {};
-		if (body.columnId) data.columnId = body.columnId;
-		if (body.position) data.position = body.position;
+	const updated = await withTenant(tenant.id, async (tx) => {
+		const card = await tx.card.findFirst({
+			where: {
+				id: params.cardId,
+				column: { board: { id: params.boardId, tenantId: tenant.id } }
+			},
+			include: { column: { include: { board: { include: { members: true } } } } }
+		});
+		if (!card) throw error(404, 'Card not found');
 
-		const updated = await prisma.card.update({
+		const member = card.column.board.members.find((m) => m.userId === locals.user!.id);
+		const isAdmin = locals.user!.globalRole === 'SITE_ADMIN' || locals.user!.tenantRole === 'ADMIN';
+		if (!member && !isAdmin) throw error(403, 'Access denied');
+		if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot edit cards');
+
+		// Handle move (column change + position)
+		if (body.columnId !== undefined || body.position !== undefined) {
+			const data: Record<string, unknown> = {};
+			if (body.columnId) data.columnId = body.columnId;
+			if (body.position) data.position = body.position;
+
+			return tx.card.update({
+				where: { id: params.cardId },
+				data,
+				include: {
+					assignees: {
+						include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+					},
+					labels: { include: { tag: true } },
+					_count: { select: { comments: true, checklists: true, attachments: true } }
+				}
+			});
+		}
+
+		// Handle content update
+		const result = cardSchema.partial().safeParse(body);
+		if (!result.success) {
+			throw error(400, result.error.issues[0].message);
+		}
+
+		const updateData: Record<string, unknown> = { ...result.data };
+		if (body.dueDate !== undefined) updateData.dueDate = body.dueDate ? new Date(body.dueDate) : null;
+		if (body.archived !== undefined) updateData.archived = body.archived;
+
+		return tx.card.update({
 			where: { id: params.cardId },
-			data,
+			data: updateData,
 			include: {
 				assignees: {
 					include: { user: { select: { id: true, name: true, avatarUrl: true } } }
@@ -75,29 +101,6 @@ export const PATCH: RequestHandler = async ({ params, request, locals }) => {
 				_count: { select: { comments: true, checklists: true, attachments: true } }
 			}
 		});
-		return json({ card: updated });
-	}
-
-	// Handle content update
-	const result = cardSchema.partial().safeParse(body);
-	if (!result.success) {
-		return json({ error: result.error.issues[0].message }, { status: 400 });
-	}
-
-	const updateData: Record<string, unknown> = { ...result.data };
-	if (body.dueDate !== undefined) updateData.dueDate = body.dueDate ? new Date(body.dueDate) : null;
-	if (body.archived !== undefined) updateData.archived = body.archived;
-
-	const updated = await prisma.card.update({
-		where: { id: params.cardId },
-		data: updateData,
-		include: {
-			assignees: {
-				include: { user: { select: { id: true, name: true, avatarUrl: true } } }
-			},
-			labels: { include: { tag: true } },
-			_count: { select: { comments: true, checklists: true, attachments: true } }
-		}
 	});
 
 	return json({ card: updated });
@@ -109,21 +112,23 @@ export const DELETE: RequestHandler = async ({ params, locals }) => {
 	if (!tenant) throw error(400, 'Unknown tenant');
 	if (!locals.user) throw error(401, 'Not authenticated');
 
-	const card = await prisma.card.findFirst({
-		where: {
-			id: params.cardId,
-			column: { board: { id: params.boardId, tenantId: tenant.id } }
-		},
-		include: { column: { include: { board: { include: { members: true } } } } }
+	await withTenant(tenant.id, async (tx) => {
+		const card = await tx.card.findFirst({
+			where: {
+				id: params.cardId,
+				column: { board: { id: params.boardId, tenantId: tenant.id } }
+			},
+			include: { column: { include: { board: { include: { members: true } } } } }
+		});
+		if (!card) throw error(404, 'Card not found');
+
+		const member = card.column.board.members.find((m) => m.userId === locals.user!.id);
+		const isAdmin = locals.user!.globalRole === 'SITE_ADMIN' || locals.user!.tenantRole === 'ADMIN';
+		if (!member && !isAdmin) throw error(403, 'Access denied');
+		if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot delete cards');
+
+		await tx.card.delete({ where: { id: params.cardId } });
 	});
-	if (!card) throw error(404, 'Card not found');
-
-	const member = card.column.board.members.find((m) => m.userId === locals.user!.id);
-	const isAdmin = locals.user.globalRole === 'SITE_ADMIN' || locals.user.tenantRole === 'ADMIN';
-	if (!member && !isAdmin) throw error(403, 'Access denied');
-	if (member && member.role === 'VIEWER') throw error(403, 'Viewers cannot delete cards');
-
-	await prisma.card.delete({ where: { id: params.cardId } });
 
 	return json({ ok: true });
 };
diff --git a/src/routes/boards/+page.server.ts b/src/routes/boards/+page.server.ts
index 33d4d25..6031db5 100644
--- a/src/routes/boards/+page.server.ts
+++ b/src/routes/boards/+page.server.ts
@@ -1,30 +1,32 @@
 import type { PageServerLoad } from './$types.js';
-import { prisma } from '$lib/server/db.js';
+import { withTenant } from '$lib/server/rls.js';
 
 export const load: PageServerLoad = async ({ locals }) => {
 	const tenant = locals.tenant;
 	if (!tenant) return { boards: [] };
 
-	const where: any = { tenantId: tenant.id, archived: false };
+	const boards = await withTenant(tenant.id, async (tx) => {
+		const where: any = { tenantId: tenant.id, archived: false };
 
-	if (!locals.user) {
-		where.visibility = 'PUBLIC';
-	} else {
-		where.OR = [
-			{ visibility: 'PUBLIC' },
-			{ members: { some: { userId: locals.user.id } } }
-		];
-	}
+		if (!locals.user) {
+			where.visibility = 'PUBLIC';
+		} else {
+			where.OR = [
+				{ visibility: 'PUBLIC' },
+				{ members: { some: { userId: locals.user.id } } }
+			];
+		}
 
-	const boards = await prisma.board.findMany({
-		where,
-		include: {
-			members: {
-				include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+		return tx.board.findMany({
+			where,
+			include: {
+				members: {
+					include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+				},
+				_count: { select: { columns: true } }
 			},
-			_count: { select: { columns: true } }
-		},
-		orderBy: { updatedAt: 'desc' }
+			orderBy: { updatedAt: 'desc' }
+		});
 	});
 
 	return { boards };
diff --git a/src/routes/boards/[boardId]/+page.server.ts b/src/routes/boards/[boardId]/+page.server.ts
index 2d29cde..f639d85 100644
--- a/src/routes/boards/[boardId]/+page.server.ts
+++ b/src/routes/boards/[boardId]/+page.server.ts
@@ -1,34 +1,36 @@
 import { error } from '@sveltejs/kit';
 import type { PageServerLoad } from './$types.js';
-import { prisma } from '$lib/server/db.js';
+import { withTenant } from '$lib/server/rls.js';
 
 export const load: PageServerLoad = async ({ params, locals }) => {
 	const tenant = locals.tenant;
 	if (!tenant) throw error(400, 'Unknown tenant');
 
-	const board = await prisma.board.findFirst({
-		where: { id: params.boardId, tenantId: tenant.id },
-		include: {
-			columns: {
-				orderBy: { position: 'asc' },
-				include: {
-					cards: {
-						where: { archived: false },
-						orderBy: { position: 'asc' },
-						include: {
-							assignees: {
-								include: { user: { select: { id: true, name: true, avatarUrl: true } } }
-							},
-							labels: { include: { tag: true } },
-							_count: { select: { comments: true, checklists: true, attachments: true } }
+	const board = await withTenant(tenant.id, async (tx) => {
+		return tx.board.findFirst({
+			where: { id: params.boardId, tenantId: tenant.id },
+			include: {
+				columns: {
+					orderBy: { position: 'asc' },
+					include: {
+						cards: {
+							where: { archived: false },
+							orderBy: { position: 'asc' },
+							include: {
+								assignees: {
+									include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+								},
+								labels: { include: { tag: true } },
+								_count: { select: { comments: true, checklists: true, attachments: true } }
+							}
 						}
 					}
+				},
+				members: {
+					include: { user: { select: { id: true, name: true, email: true, avatarUrl: true } } }
 				}
-			},
-			members: {
-				include: { user: { select: { id: true, name: true, email: true, avatarUrl: true } } }
 			}
-		}
+		});
 	});
 
 	if (!board) throw error(404, 'Board not found');