Fixing 407 and authentication failures

An HTTP 407 ("Proxy Authentication Required") means the proxy received your request but rejected the credentials attached to it. It's almost always a credentials or formatting issue, not a network problem.

Most common causes

• Credentials pasted with a trailing space or newline character
• Username and password swapped in the config
• Using a username generated for one batch with a port from a different one
• Proxy string missing the scheme (http://) that some libraries require even for proxy URLs
• Balance at zero — some clients surface an empty balance as an auth error rather than a clear billing message

How to fix it

1. 1Generate a brand-new batch from Generate proxies rather than reusing an old one you're unsure about.
2. 2Copy the full line and paste it directly into a plain cURL test first, before touching your application code.
3. 3If cURL works but your application still fails, the issue is in how your code parses or passes the proxy string — check for accidental URL-encoding of the @ or : characters.