What is the CONNECT method?
The CONNECT method is used by clients to ask a proxy to establish a TCP tunnel to a destination server, most commonly to relay end-to-end encrypted HTTPS traffic through the proxy.
API Usage & Best Practices
- Proxy tunnelling: CONNECT targets a proxy so it can open a raw connection to an origin server, after which bytes flow through untouched.
- Secure by design: The proxy cannot read the tunnelled payload, which is why CONNECT underpins HTTPS-over-proxy setups.
- Authenticate first: Proxies frequently require credentials, returning 407 until valid proxy authentication is supplied.
Common Response Codes
- 200 OK: The tunnel was established and the connection is now transparent.
- 407 Proxy Authentication Required: The proxy needs credentials before opening the tunnel.
- 405 Method Not Allowed: The server or proxy does not permit CONNECT.
