---
title: Proxy-Authorization
summary: null
url: >-
  https://www.fastly.com/documentation/reference/http/http-headers/Proxy-Authorization
---

The HTTP `Proxy-Authorization` request header is usually sent after a server has responded with a `407 Proxy Authentication Required` response containing a `Proxy-Authenticate` response header.

The `Proxy-Authorization` header field allows the client to identify itself (or its user) to a proxy that requires authentication. Its value consists of credentials containing the authentication information of the client for the proxy and/or realm of the resource being requested.

Unlike `Authorization`, the `Proxy-Authorization` header field applies only to the next inbound proxy that demanded authentication using the `Proxy-Authenticate` field. When multiple proxies are used in a chain, the `Proxy-Authorization` header field is consumed by the first inbound proxy that was expecting to receive credentials. A proxy MAY relay the credentials from the client request to the next proxy if that is the mechanism by which the proxies cooperatively authenticate a given request.