diff --git a/server/src/prisma/prisma.service.ts b/server/src/prisma/prisma.service.ts
index a18770c..1834b3e 100644
--- a/server/src/prisma/prisma.service.ts
+++ b/server/src/prisma/prisma.service.ts
@@ -1,5 +1,57 @@
 import { Injectable } from '@nestjs/common'
-import { PrismaClient } from '@prisma/client'
+import { PrismaClient, } from '@prisma/client'
+
+async function updateUserMoney(prisma: PrismaClient): Promise<void> {
+  // On calcule le solde par utilisateur⋅rice pour mettre à jour l'objet User
+  const moneyPerUser = await prisma.moneyUpdate.groupBy({
+    by: 'userId',
+    _sum: {
+      amount: true,
+    }
+  })
+  for (const { userId, _sum } of moneyPerUser) {
+    const { amount } = _sum
+    await prisma.user.update({
+      where: {
+        id: userId,
+      },
+      data: {
+        money: amount
+      }
+    })
+  }
+  // On réinitialise le solde s'il n'y a plus aucun MoneyUpdate
+  await prisma.user.updateMany({
+    where: {
+      moneyUpdates: { none: {} }
+    },
+    data: {
+      money: 0
+    },
+  })
+}
+
+function extendPrismaClient() {
+  const prisma = new PrismaClient()
+  return prisma.$extends({
+    query: {
+      moneyUpdate: {
+        $allOperations({ model, operation, args, query }) {
+          const result = query(args)
+          if (!operation.startsWith("find") && !['aggregate', 'count', 'groupBy'].includes(operation))
+            result.then(() => updateUserMoney(prisma))
+          return result
+        }
+      }
+    }
+  })
+}
+
+const ExtendedPrismaClient = class {
+  constructor() {
+    return extendPrismaClient()
+  }
+} as new () => ReturnType<typeof extendPrismaClient>
 
 @Injectable()
-export class PrismaService extends PrismaClient {}
+export class PrismaService extends ExtendedPrismaClient {}