Zero to a service
that answers.
No runtime to install, no container to build, nothing to configure. One binary in, one binary out.

$ curl -fsSL https://kern-lang.eu/install.sh | sh
$ kern new api my-service && cd my-service
$ kern run
my-service listening on :8080
$ curl localhost:8080/health
{"status": "ok"}
$
That is a real HTTP service.
Not a hello stub. It compiles to a native binary of about 115 KB that you can copy to a scratch container or a bare VM and run. There is no interpreter, no VM, and no node_modules.
Read “Try kern in five minutes”Then the part
people re-read.
In kern these are compile errors: they cannot reach production, cannot be suppressed in a hurry, and cannot survive a distracted code review.
E0300A query built from user input does not compile.
The same rule covers shell, URL, regex and template strings.
E0302Personal data reaching the wrong place does not compile.
Tag a field as personal once and the compiler follows it into every sink.
E0303Model output reaching a sink does not compile.
Anything an LLM returns comes back marked untrusted.
E0404A module without authority cannot open a socket.
Authority is an argument you pass, so an audit reads the grants.