---
title: tls.client.tlsexts_list_txt
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/variables/client-connection/tls-client-tlsexts-list-txt
---

**Type:** STRING  
**Access:** read-only

**Available in:** recv, hash, deliver, log

The list of TLS extensions supported by the client, rendered as text in a 
colon-separated list. The value returned will be consistent with the 
[IANA Cipher Suite Name](https://testssl.sh/openssl-iana.mapping.html).