HTTP registry: next-protocol
The next-protocol parameter's value indicates the Application-Layer Protocol Negotiation (ALPN) protocol identifierof the protocol used by the intermediary to connect to the next hop when obtaining this response.
Proxy and gateway values describe processing across trust boundaries where fields, authority, and framing may be transformed. next-protocol is registered in HTTP Proxy-Status Parameters. Defining reference: rfc9209.
Identifier (http)
next-protocol
The next-protocol parameter's value indicates the Application-Layer Protocol Negotiation (ALPN) protocol identifierof the protocol used by the intermediary to connect to the next hop when obtaining this response.
Strip hop-by-hop data, normalize framing, trust forwarded metadata only from configured proxies, and avoid exposing topology or credentials.
This registry value is currently marked active by IANA. Follow the defining specification before sending, accepting, or proxying it.
IANA registry: http-proxy-status/http-proxy-status-parameters
Registry reference: rfc9209