407 🌐 HTTP

HTTP 407 Proxy Authentication Required

A proxy between you and the server requires credentials before it will forward your request.

Seen on: Linux npm Git

Meaning

407 is like 401 but for a proxy (often a corporate proxy). The proxy returns a Proxy-Authenticate header; the client must resend with Proxy-Authorization. Command-line tools (npm, git, pip, curl) commonly hit this inside company networks.

Common causes

  • Corporate proxy requires a username/password or NTLM/Kerberos auth
  • Proxy credentials expired or password changed
  • Tool not configured to use the proxy credentials (npm, git, pip, Docker)
  • Special characters in the password not URL-encoded in the proxy URL

⚡ Quick fix

  1. Set HTTP_PROXY/HTTPS_PROXY with credentials: http://user:pass@proxy:8080
  2. URL-encode special characters in the password (@ → %40)
  3. Configure each tool: npm config set proxy …, git config --global http.proxy …
  4. For NTLM proxies, run a local helper like Cntlm or Px

Detailed fix by platform

Linux

  1. Environment variables used by most CLIs:
    bash
    export HTTP_PROXY="http://user:p%40ss@proxy.corp:8080"
export HTTPS_PROXY="$HTTP_PROXY"
export NO_PROXY="localhost,127.0.0.1,.corp.local"

npm

  1. npm config set proxy http://user:pass@proxy:8080 and npm config set https-proxy ….

Git

  1. git config --global http.proxy http://user:pass@proxy:8080.

How to diagnose

  1. Network — Are you behind a corporate proxy or VPN?
  2. Tool config — Does this tool read HTTP(S)_PROXY or need its own config?
  3. Credentials — Are they current and URL-encoded?
  4. Auth type — Does the proxy require NTLM/Kerberos instead of Basic?

🧠 Still stuck? Analyze your error

Paste the full message, response headers or stack trace — we'll detect the platform and point to the most likely cause.