What it means
A proxy between the client and server requires authentication before forwarding the request.
Common causes
- Corporate proxy needs login
- Proxy credentials in HTTP_PROXY are missing or wrong
- Tools like npm or pip not configured for the proxy
How to fix it
As a client or visitor
Configure proxy credentials, for example http://user:pass@proxy:8080 in HTTPS_PROXY, or the tool's own proxy settings.
As the site or API owner
The proxy must send Proxy-Authenticate with the scheme it accepts.
Example response
HTTP/1.1
HTTP/1.1 407 Proxy Authentication Required
Date: Tue, 07 Oct 2025 09:30:00 GMT
Server: nginx
Proxy-Authenticate: Basic realm="corp-proxy"
Content-Length: 0Specification
FAQ
› How do I fix 407 in npm or git?
Set the proxy with credentials (npm config set proxy, git config http.proxy) or use a local auth helper for NTLM proxies.
› 407 vs 401?
401 comes from the origin server; 407 comes from a proxy on the way.