---
title: client.socket.tcpi_notsent_bytes
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/variables/client-connection/client-socket-tcpi-notsent-bytes
---

**Type:** INTEGER  
**Access:** read-only

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

The number of bytes queued for transmission in the socket buffer that
have not yet been written at least once to the client.