The fetch client returns standard promises, so it fits naturally into whatever async pattern your framework uses.

SolidJS

import { createResource } from "solid-js";
import fetchClients from "_/fetch";

const { GET } = fetchClients["users/[id]"];

function UserProfile(props) {
  const [user] = createResource(() => props.userId, (id) => GET([id]));

  return (
    <div>
      {user.loading && <div>Loading...</div>}
      {user() && <div>{user().name}</div>}
    </div>
  );
}

React

import { useState, useEffect } from "react";
import fetchClients from "_/fetch";

const { GET } = fetchClients["users/[id]"];

function useUser(userId: number) {
  const [user, setUser] = useState(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  useEffect(() => {
    GET([userId])
      .then(setUser)
      .catch(setError)
      .finally(() => setLoading(false));
  }, [userId]);

  return { user, loading, error };
}

Types flow through these abstractions - hooks and components automatically know the response shape from your API definition.