diff --git a/packages/core/src/utils/log.ts b/packages/core/src/utils/log.ts
index c2224a5e..2476d222 100644
--- a/packages/core/src/utils/log.ts
+++ b/packages/core/src/utils/log.ts
@@ -4,6 +4,11 @@ import fs from "fs/promises";
 import { Context } from "../context.js";
 import { Global } from "../global/index.js";
 
+type Tags = {
+  service: string;
+  [key: string]: any; // any other optional keys
+};
+
 export namespace Log {
   const ctx = Context.create<{
     tags: Record<string, any>;
@@ -102,8 +107,8 @@ export namespace Log {
   }
 
   let last = Date.now();
-  export function create(tags?: Record<string, any>) {
-    tags = tags || {};
+  export function create(tags: Tags) {
+    tags = tags || { service: "default" };
 
     const service = tags["service"];
     if (service && typeof service === "string") {