> For the complete documentation index, see [llms.txt](https://faq.finerymarkets.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://faq.finerymarkets.com/api-reference/troubleshooting-errors/error-6.md).

# Error 6

Error 6 Invalid nonce may occur when sending a REST request or connecting a websocket.  

* Make sure your nonce is unique within a 2-minute window per API key.
* Try another API key.