---
title: "CopFailureReason"
source: "https://github.com/remix-run/remix/blob/8905f3943706e1f53696ab83e70a84873cabfc90/packages/cop-middleware/src/lib/cop.ts#L18"
---

# CopFailureReason

## Summary

Reason reported when cross-origin protection rejects a request.

## Signature

```ts
type CopFailureReason = 'cross-origin-request' | 'cross-origin-request-from-old-browser'

```