Is it possible to use Vuex without Vue? (Vuex server-side?)

TL;DR you can perfectly use Vuex in node (without a browser), even for unit testing. Internally, though, Vuex still uses some code from Vue.

You can't use Vuex without Vue. Because:

• Vuex checks for the existence of Vue.
• Vuex depends largely on Vue for its reactivity inner workings.

That being said, you do require Vue, but you don't require a Vue instance. You don't even require the browser.

So yes, it is pretty usable in the server-side, standalone.

For instance, you could run it using Node.js as follows:

• Create a sample project:

  npm init -y
  

• Install the dependencies (note: axios is not necessary, we are adding it just for this demo):

  npm install --save vue vuex axios
  

• Create a script (index.js):

  const axios = require('axios');
  const Vue = require('vue');
  const Vuex = require('vuex');
  Vue.use(Vuex);
  
  const store = new Vuex.Store({
    strict: true,
    state: {name: "John"},
    mutations: {
      changeName(state, data) {
          state.name = data
      }
    },
    actions: {
      fetchRandomName({ commit }) {
        let randomId = Math.floor(Math.random() * 12) + 1  ;
        return axios.get("https://reqres.in/api/users/" + randomId).then(response => {
          commit('changeName', response.data.data.first_name)
        })
      }
    },
    getters: {
      getName: state => state.name,
      getTransformedName: (state) => (upperOrLower) => {
        return upperOrLower ? state.name.toUpperCase() : state.name.toLowerCase()
      }
    }
  });
  console.log('via regular getter:', store.getters.getName);
  console.log('via method-style getter:', store.getters.getTransformedName(true));
  
  store.commit('changeName', 'Charles');
  console.log('after commit:', store.getters.getName);
  
  store.dispatch('fetchRandomName').then(() => {
      console.log('after fetch:', store.getters.getName);
  });
  

• Run it:

  node index.js
  

• It will output:

  via regular getter: John
  via method-style getter: JOHN
  after commit: Charles
  after fetch: Byron