vuex + vuelidate

user.js

import Vue from 'vue'
import { validationMixin } from 'vuelidate'
import { required, minLength } from 'vuelidate/lib/validators'

export default function (store) {
  const validator = new Vue({
    mixins: [
      validationMixin
    ],
    computed: {
      name () {
        return store.getters['user/name']
      }
    },
    validations: {
      name: { required, minLength: minLength(3) }
    }
  })

  const module = {
    namespaced: true,
    state: {
      name: '',
    },
    getters: {
      name (state) {
        return state.name
      },
      $v (state) {
        // don't expose api
        return Object.assign({}, validator.$v)
      }
    },
    actions: {
      $touch () {
        validator.$v.$touch()
      },
      name ({ commit }, value) {
        commit('name', value)
      }
    },
    mutations: {
      name (state, value) {
        state.name = value
      }
    }
  }
  
  return module;
}

Ohh, i found a solution for this.

Using the store.registerModule.

Sorry by the flood.