diff --git a/packages/services/agent-service/src/infrastructure/stt/openai-stt.service.ts b/packages/services/agent-service/src/infrastructure/stt/openai-stt.service.ts
index 5d7f8c7..fe34a06 100644
--- a/packages/services/agent-service/src/infrastructure/stt/openai-stt.service.ts
+++ b/packages/services/agent-service/src/infrastructure/stt/openai-stt.service.ts
@@ -17,10 +17,11 @@ export class OpenAISttService {
 
   constructor(private readonly configService: ConfigService) {
     this.apiKey = this.configService.get<string>('OPENAI_API_KEY', '');
+    // Strip trailing slash and /v1 suffix — we always append /v1/...
     this.baseUrl = this.configService.get<string>(
       'OPENAI_BASE_URL',
       'https://api.openai.com',
-    ).replace(/\/$/, '');
+    ).replace(/\/$/, '').replace(/\/v1$/, '');
   }
 
   /**