diff --git a/src/cache.ts b/src/cache.ts
index 35a31c1..c1d2552 100644
--- a/src/cache.ts
+++ b/src/cache.ts
@@ -114,3 +114,8 @@ export enum CompressionMethod {
   ZstdWithoutLong = "zstd-without-long",
   Zstd = "zstd",
 }
+// Refer: https://github.com/actions/cache/blob/12681847c623a9274356751fdf0a63576ff3f846/src/utils/actionUtils.ts#L53
+const RefKey = "GITHUB_REF";
+export function isValidEvent(): boolean {
+  return RefKey in process.env && Boolean(process.env[RefKey]);
+}
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