diff --git a/packages/core/src/core/loggingContentGenerator.ts b/packages/core/src/core/loggingContentGenerator.ts
index c4b89115..a1fdb897 100644
--- a/packages/core/src/core/loggingContentGenerator.ts
+++ b/packages/core/src/core/loggingContentGenerator.ts
@@ -113,7 +113,7 @@ export class LoggingContentGenerator implements ContentGenerator {
     this.logApiRequest(toContents(req.contents), req.model, userPromptId);
     try {
       const sessionId = this.config.getSessionId();
-      const fileName = `${sessionId}.gemini-api-request.${this.requestCounter}.json`;
+      const fileName = `regex.${sessionId}.gemini-api-request.${this.requestCounter}.json`;
       const filePath = path.join('/tmp', fileName);
       const jsonPayload = JSON.stringify(req, null, 2);
       fs.writeFileSync(filePath, jsonPayload);
@@ -142,7 +142,7 @@ export class LoggingContentGenerator implements ContentGenerator {
     this.logApiRequest(toContents(req.contents), req.model, userPromptId);
 
     const sessionId = this.config.getSessionId();
-    const fileName = `${sessionId}.gemini-api-request.${this.requestCounter}.json`;
+    const fileName = `regex.${sessionId}.gemini-api-request.${this.requestCounter}.json`;
     const filePath = path.join('/tmp', fileName);
     const jsonPayload = JSON.stringify(req, null, 2);
     fs.writeFileSync(filePath, jsonPayload);