GuidesProxy error codes: which hop sent it and how to fix it
Proxy error codes decoded by hop: which ones the proxy sends, which come from the target, how to read them with curl -v, and which ones are safe to retry.14 min read→GuidesOkHttp proxy: auth, SOCKS5, rotation and 407 fixes
OkHttp proxy setup in Kotlin and Java for OkHttp 4.12 and 5.x: proxyAuthenticator done right, SOCKS5 logins, the system proxy, rotation and the 407 traps.15 min read→Guides407 Proxy Authentication Required: causes and client fixes
A 407 means the proxy, not the site, rejected or never got your login. Causes in the order to check, and the fix for curl, Python, Node, browsers and apt.15 min read→