actions.js

export function loadAllTodos() {
  const promise = new Promise((resolve, reject) => {

    Api.get()
    .then(res => {
      resolve(res);
    })
    .catch(err => {
      reject(err);
    })

  });

  return dispatch(loadAllTodos, promise);

}

render.js

router.run((Handler, routerState) => {
    var p = Promise.all(routerState.routes
    .filter(route => route.handler.fetchData)  // définit fetchData
    .map(route => {
      return route.handler.fetchData();
    })
  );
  p.then( resp => {
      //I don't need resp, just update the state
      appState = state.get().toJS()
    const html = loadAppStateThenRenderHtml(Handler, appState);
      const notFound = routerState.routes.some(route => route.name === 'not-found');
      const status = notFound ? 404 : 200;
      res.status(status).send(html);
      resolve();
  });
});

store.js

case actions.loadAllTodos:
        todosCursor(todos => {
          return todos.update('list', list => list.withMutations(list => {
            const newTodos = data;
            newTodos.forEach(todo =>{
              list.push(new Todo({
                id: todo.id,
                title: todo.title
              }));
            });
          }));
        });
        break;

todos.react.js

class Todos extends Component {

  fetchData(param) {
    return actions.loadAllTodos();
  }

  componentDidMount() {
    this.fetchData();
  }
  
  ...