.

app/api/businesses/route.ts

@@ -76,6 +76,7 @@ export async function POST(request: NextRequest) {
         // We must exclude 'id', 'offers', 'owner', 'createdAt', 'updatedAt' from the data object
         const cleanData: any = {
             name: data.name || "Nouvelle Entreprise",
+            slug: data.slug || null,
             category: data.category || "Autre",
             location: data.location || "Ma Ville",
             description: data.description || "",
@@ -93,6 +94,21 @@ export async function POST(request: NextRequest) {
             founderImageUrl: data.founderImageUrl || null,
             keyMetric: data.keyMetric || null,
         }
+        
+        // 2. Slug Uniqueness Check
+        if (cleanData.slug) {
+            const slugConflict = await prisma.business.findFirst({
+                where: {
+                    slug: cleanData.slug,
+                    NOT: { ownerId: ownerId } // Important: allow the owner to keep their own slug
+                }
+            });
+            if (slugConflict) {
+                return NextResponse.json({ 
+                    error: `Le lien personnalisé "${cleanData.slug}" est déjà utilisé par une autre entreprise. Veuillez en choisir un autre.` 
+                }, { status: 400 });
+            }
+        }
 
         let business;
         const existing = await prisma.business.findFirst({