URLs and Ports

While Signal K is a transport-agnostic protocol, there are certain conventions that have been established for use on the Web and by clients and servers using HTTP and WebSockets.

Ports

The Signal K HTTP and WebSocket services SHOULD be found on the usual HTTP/S ports (80 or 443). The services SHOULD be found on the same port, but may be configured for independent ports and MAY be configured for ports other than HTTP/S.

A Signal K server MAY offer Signal K over TCP or UDP, these services SHOULD be on port 8375¹.

If an alternate port is needed it SHOULD be an arbitrary high port in the range 49152–65535².

URL Prefix

The Signal K applications start from the /signalk root. This provides some protection against name collisions with other applications on the same server. Therefore the Signal K entry point will always be found by loading http(s)://«host»:«port»/signalk.

[1] This has not been registered with IANA yet. It is the ASCII decimal code for SK.
[2] This is the private use section of IP ports specified as reserved by IANA.