Can I submit my form using websockets?

Yes. redux-form has built-in support for managing submitting state and errors using promises, but you can easily replicate its behavior using any other asynchronous paradigm. All you need do is to dispatch the START_SUBMIT and STOP_SUBMIT actions yourself using the exported Action Creators.

import {startSubmit, stopSubmit} from 'redux-form';

function submitForm(data, dispatch) {
  // tell redux-form that the submission has started
  dispatch(startSubmit('myFormName'));

  channels.methods.push('submit:myFormName', {data})
    receive('ok', () => {
      // tell redux-form that the submission has stopped
      dispatch(stopSubmit('myFormName'));
      // ^ not necessary if you are redirecting or doing something
      //   else that will result in the form state being destroyed
    })
    .receive('error', response => {
      const {errors} = response;
      // tell redux-form that the submission has stopped with errors
      dispatch(stopSubmit('myFormName', errors));
    });
}

The submitForm function can then be passed either as an onSubmit prop to your decorated form or as a parameter to handleSubmit() inside your form component. For more on this, look at the handleSubmit() docs.

Thanks to Vlad Shcherbin for presenting his solution, from which this answer was modeled.