{
  // Add apollo module
  modules: ['@nuxtjs/apollo'],

  // Give apollo module options
  apollo: {
    tokenName: 'yourApolloTokenName', // optional, default: apollo-token
    includeNodeModules: true, // optional, default: false (this includes graphql-tag for node_modules folder)
    authenticationType: 'Basic', // optional, default: 'Bearer'
    // required
    clientConfigs: {
      default: {
        // required  
        httpEndpoint: 'http://localhost:4000',
        // You can use `wss` for secure connection (recommended in production)
        // Use `null` to disable subscriptions
        wsEndpoint: 'http://localhost:4000', // optional
        // LocalStorage token
        tokenName: 'apollo-token', // optional
        // Enable Automatic Query persisting with Apollo Engine
        persisting: false, // Optional
        // Use websockets for everything (no HTTP)
        // You need to pass a `wsEndpoint` for this to work
        websocketsOnly: false // Optional
      },
      test: {
        httpEndpoint: 'http://localhost:5000',
        wsEndpoint: 'http://localhost:5000',
        tokenName: 'apollo-token'
      }
    }
  }
}

 // set your graphql-token
 this.$apolloHelpers.onLogin(token, /* if not default you can pass in client as second argument */)
 // unset your graphql-token
 this.$apolloHelpers.onLogout(/* if not default you can pass in client as second argument */)
 // get your current token (we persist token in a cookie)
 this.$apolloHelpers.getToken(/* you can provide named tokenName if not 'apollo-token' */)

  apollo: {
    clientConfigs: {
      default: {
        httpEndpoint: 'https://graphql.datocms.com',
        getAuth: () => 'Bearer your_token_string'
      },
    }
  },

methods:{
  async onSubmit () {
    const credentials = this.credentials
    try {
        const res = await this.$apollo.mutate({
            mutation: authenticateUserGql,
            variables: credentials
        }).then(({data}) => data && data.authenticateUser)
        await this.$apolloHelpers.onLogin(res.token)
    } catch (e) {
        console.error(e)
    }
  },
}

methods:{
  async onLogout () {
    await this.$apolloHelpers.onLogout()
  },
}

// middleware/isAuth.js
  export default function ({app, error}) {
    const hasToken = !!app.$apolloHelpers.getToken()
    if (!hasToken) {
        error({errorCode:503, message:'You are not allowed to see this'})
    }
}

export default {
  actions: {
    foo (store, payload) {
      let client = this.app.apolloProvider.defaultClient
    }
  }
}

export default {
  asyncData (context) {
    let client = context.app.apolloProvider.defaultClient
  }
}

export default {
  nuxtServerInit (store, context) {
    let client = context.app.apolloProvider.defaultClient
  }
}

export default {
  methods:{
    foo(){
      // receive the associated Apollo client 
      const client = this.$apollo.getClient()

      // most likely you would call mutations like following:
      this.$apollo.mutate({mutation, variables})
    }
  }
}

export default {
  apollo: {
    foo: {
      query: fooGql,
      variables () {
        return {
          myVar: this.myVar
        }
      }
    }
  }
}

  apollo: {
    clientConfigs: {
      default: '~/apollo/client-configs/default.js'
    },
    includeNodeModules: true
  }

// nuxt.config.js
apollo:{
 clientConfigs:{
  default:{
    httpEndpoint: YOUR_ENDPOINT,
    wsEndpoint: YOUR_WS_ENDPOINT
  }
 }
}