diff --git a/app/api/missions/route.ts b/app/api/missions/route.ts
index 46d91302..9be8778e 100644
--- a/app/api/missions/route.ts
+++ b/app/api/missions/route.ts
@@ -144,13 +144,11 @@ export async function POST(request: Request) {
     // Validate required fields
     const requiredFields = {
       name,
-      oddScope,
       niveau,
       intention,
       missionType,
       donneurDOrdre,
-      projection,
-      participation
+      projection
     };
 
     const missingFields = Object.entries(requiredFields)
@@ -180,7 +178,7 @@ export async function POST(request: Request) {
     const mission = await prisma.mission.create({
       data: {
         name,
-        oddScope,
+        oddScope: oddScope || 'default',
         niveau,
         intention,
         missionType,
@@ -188,7 +186,7 @@ export async function POST(request: Request) {
         projection,
         services: Array.isArray(services) ? services.filter(Boolean) : [],
         profils: Array.isArray(profils) ? profils.filter(Boolean) : [],
-        participation,
+        participation: participation || 'default',
         creatorId: userId
       }
     });
diff --git a/lib/services/n8n-service.ts b/lib/services/n8n-service.ts
index fa307688..06cb2f11 100644
--- a/lib/services/n8n-service.ts
+++ b/lib/services/n8n-service.ts
@@ -18,16 +18,18 @@ export class N8nService {
 
   async triggerMissionCreation(data: any): Promise<any> {
     try {
-      // Add API key to the data
-      const dataWithApiKey = {
+      // Add API key and default values to the data
+      const dataWithDefaults = {
         ...data,
+        oddScope: data.oddScope || 'default',
+        participation: data.participation || 'default',
         config: {
           ...data.config,
           N8N_API_KEY: this.apiKey
         }
       };
 
-      console.log('Triggering n8n workflow with data:', JSON.stringify(dataWithApiKey, null, 2));
+      console.log('Triggering n8n workflow with data:', JSON.stringify(dataWithDefaults, null, 2));
       console.log('Using webhook URL:', this.webhookUrl);
       console.log('API key present:', !!this.apiKey);
 
@@ -39,7 +41,7 @@ export class N8nService {
           'Content-Type': 'application/json',
           'x-api-key': this.apiKey
         },
-        body: dataWithApiKey
+        body: dataWithDefaults
       };
       console.log('Full request details:', JSON.stringify(requestDetails, null, 2));
 
@@ -49,7 +51,7 @@ export class N8nService {
           'Content-Type': 'application/json',
           'x-api-key': this.apiKey
         },
-        body: JSON.stringify(dataWithApiKey),
+        body: JSON.stringify(dataWithDefaults),
       });
 
       console.log('Webhook response status:', response.status);