Is your objection just to C++ syntax in general (in which case: total agreement) or something particular about OKWS? It seems pretty self-explanatory, as far as C++ goes:

  okclnt_t *make_newclnt (ptr<ahttpcon> x);

This declares a function that makes a new client from an http connection. It returns a raw pointer, so I presume the caller is responsible for the client lifetime. Whereas the connection argument is some ptr template, which I expect is a ref-counted or otherwise managed pointer, which suggests the client will keep the connection object alive. This is copying the ptr value, which if this is a ref-counting ptr would do an unnecessary extra ref-count during the function call, so they might want to pass it as a const-ref instead.

  okclnt_simple_t (ptr<ahttpcon> x, oksrvc_simple_t *o) : okclnt2_t (x, o), ok_simple (o) {}

This is a constructor to make a simple client from an http connection and a simple service. The only thing unusual is that a _t suffix usually suggests a typedef, and I don't think you can use a type alias to define a constructor.

I haven't looked at the API or done any web programming; I thought it was interesting what I could tell from this snippet regardless.