feat: add mau limit to web-app survey (#828)

apps/web/app/api/v1/js/sync/lib/sync.ts

@@ -1,7 +1,8 @@
 import { getSurveysCached } from "@/app/api/v1/js/surveys";
+import { MAU_LIMIT } from "@formbricks/lib/constants";
 import { getActionClassesCached } from "@formbricks/lib/services/actionClass";
 import { getEnvironmentCached } from "@formbricks/lib/services/environment";
-import { createPerson, getPersonCached } from "@formbricks/lib/services/person";
+import { createPerson, getMonthlyActivePeopleCount, getPersonCached } from "@formbricks/lib/services/person";
 import { getProductByEnvironmentIdCached } from "@formbricks/lib/services/product";
 import { createSession, extendSession, getSessionCached } from "@formbricks/lib/services/session";
 import { captureTelemetry } from "@formbricks/lib/telemetry";
@@ -31,6 +32,28 @@ export const getUpdatedState = async (
     throw new Error("Environment does not exist");
   }
 
+  // check if Monthly Active Users limit is reached
+  const currentMau = await getMonthlyActivePeopleCount(environmentId);
+  const isMauLimitReached = currentMau >= MAU_LIMIT;
+  if (isMauLimitReached) {
+    const errorMessage = `Monthly Active Users limit reached in ${environmentId} (${currentMau}/${MAU_LIMIT})`;
+    if (!personId || !sessionId) {
+      // don't allow new people or sessions
+      throw new Error(errorMessage);
+    }
+    const session = await getSessionCached(sessionId);
+    if (!session) {
+      // don't allow new sessions
+      throw new Error(errorMessage);
+    }
+    // check if session was created this month (user already active this month)
+    const now = new Date();
+    const firstDayOfMonth = new Date(now.getFullYear(), now.getMonth(), 1);
+    if (new Date(session.createdAt) < firstDayOfMonth) {
+      throw new Error(errorMessage);
+    }
+  }
+
   if (!personId) {
     // create a new person
     person = await createPerson(environmentId);

apps/web/app/api/v1/js/sync/route.ts

@@ -29,7 +29,7 @@ export async function POST(req: Request): Promise<NextResponse> {
 
     return responses.successResponse({ ...state }, true);
   } catch (error) {
-    console.error(error);
+    console.error(error.message);
     return responses.internalServerErrorResponse(
       "Unable to complete response. See server logs for details.",
       true

packages/lib/constants.ts

@@ -1,6 +1,7 @@
 export const RESPONSES_LIMIT_FREE = 100;
 export const IS_FORMBRICKS_CLOUD = process.env.NEXT_PUBLIC_IS_FORMBRICKS_CLOUD === "1";
 export const REVALIDATION_INTERVAL = 0; //TODO: find a good way to cache and revalidate data when it changes
+export const MAU_LIMIT = IS_FORMBRICKS_CLOUD ? 5000 : 1000000;
 
 // URLs
 const VERCEL_URL = process.env.NEXT_PUBLIC_VERCEL_URL ? `https://${process.env.NEXT_PUBLIC_VERCEL_URL}` : "";

packages/lib/services/person.ts

@@ -237,3 +237,34 @@ export const getOrCreatePersonByUserId = async (userId: string, environmentId: s
     return transformPrismaPerson(personPrisma);
   }
 };
+
+export const getMonthlyActivePeopleCount = async (environmentId: string): Promise<number> =>
+  await unstable_cache(
+    async () => {
+      const now = new Date();
+      const firstDayOfMonth = new Date(now.getFullYear(), now.getMonth(), 1);
+
+      const aggregations = await prisma.person.aggregate({
+        _count: {
+          id: true,
+        },
+        where: {
+          environmentId,
+          sessions: {
+            some: {
+              createdAt: {
+                gte: firstDayOfMonth,
+              },
+            },
+          },
+        },
+      });
+
+      return aggregations._count.id;
+    },
+    [`env-${environmentId}-mau`],
+    {
+      tags: [`env-${environmentId}-mau`],
+      revalidate: 60 * 60 * 6, // 6 hours
+    }
+  )();