docs/api/core/controllers/index.md
# Core >> Controllers || 10
Apollo Controllers provide the interface between your custom elements and the Apollo Client. Use them to add queries, mutations, and subscriptions to your custom elements.
- [`ApolloQueryController`](./query/) - for fetching GraphQL data
- [`ApolloMutationController`](./mutation/) - for updating your graph
- [`ApolloSubscriptionController`](./subscription/) - for real-time data