Proxy Authentication

Proxy authentication is how a client proves it is authorized to route traffic through an intermediary proxy gateway, preventing unauthorized transit and metering bandwidth. Verification occurs through two primary methods: credentials embedded in connection strings, or an ip whitelist proxy setup where the gateway only accepts requests from pre-registered source IP addresses. Mismatching authentication to your host environment (such as configuring IP whitelisting on cloud runners with ephemeral egress IPs) is the leading cause of 407 Proxy Authentication Required failures.

In scraping pipelines, configuring curl proxy auth or client pools requires embedding the proxy username password directly into the transport URL (http://user:pass@proxy.host:port) or dispatching a base64 Proxy-Authorization header. When configuring proxies for web scraping, teams test transport handshakes with a cURL with proxy setup before deploying scrapers. For production pipelines, combining cURL with proxy and MrScraper API offloads proxy authentication directly to managed endpoint headers.

Key Specifications & Comparison