Why Apollo Client?

Apollo Client is a comprehensive state-management library for JavaScript. With GraphQL, it manages both local and remote data through a single, normalized cache. Apollo Client is view-layer agnostic, and Vue Apollo provides the official Vue.js integration.

Declarative data fetching

You write a query, and Apollo Client handles fetching, caching, and updating the UI:

<script setup lang="ts">
const { current } = useQuery(gql`
  query GetTodos {
    todos {
      id
      text
      completed
    }
  }
`)
</script>

You do not need to track loading states by hand, juggle error branches, or update the cache after every mutation. Apollo Client handles all of it.

Normalized caching

Apollo Client stores responses in a normalized, in-memory cache. When the same data is queried again, it returns from the cache instantly:

const client = new ApolloClient({
  link: new HttpLink({ uri: '/graphql' }),
  cache: new InMemoryCache(),
})

Because the cache is normalized by __typename + id, any query that reads an entity updates automatically when that entity changes elsewhere. A mutation that touches a User:42 is reflected immediately in every component that displays it.

Vue-native reactivity

Vue Apollo plugs into Vue's reactivity system. Query variables can be refs, reactive objects, getters, or even per-key reactive maps:

<script setup lang="ts">
const userId = ref('1')

const { current } = useQuery(gql`
  query User($id: ID!) {
    user(id: $id) {
      id
      name
    }
  }
`, {
  variables: { id: userId },
})
</script>

When userId changes, the query re-executes with the new value. No watcher boilerplate required.

TypeScript support

With GraphQL Codegen, every query, mutation, and result is fully typed end-to-end:

const UserQuery = graphql(`
  query User($id: ID!) {
    user(id: $id) {
      id
      name
      email
    }
  }
`)

const { current } = useQuery(UserQuery, { variables: { id: '1' } })

current.result is typed precisely, including narrowing by current.resultState so partial and streaming states are handled safely.

When to use Apollo Client

Apollo Client is a good fit when:

• Your backend speaks GraphQL.
• You need automatic caching with cross-query consistency.
• You want real-time updates through subscriptions, @defer, or @stream.
• You value TypeScript correctness throughout the stack.

For simple REST APIs or apps that do little caching, lighter alternatives exist. For GraphQL apps with non-trivial caching needs, Apollo Client is the most complete option.