@defer and @stream directives — send partial query results incrementally

A query that includes both fast fields and a slow expensive field blocks the entire response until all resolvers complete. Users see nothing until the slowest resolver finishes.

Use @defer on slow fragments and @stream on lists to receive partial results as they resolve.

query GetDashboard {
  user {
    id
    name
    # Fast — delivered immediately
    recentOrders(limit: 5) { id total }
    # Slow analytics — deferred
    ... on User @defer {
      analyticsData {
        totalRevenue
        conversionRate
      }
    }
  }
  # Stream large list as items resolve
  allProducts @stream(initialCount: 3) {
    id
    name
  }
}

// Apollo Client — handle incremental results
const { data, loading } = useQuery(DASHBOARD_QUERY);
// data builds up incrementally as deferred fragments arrive
// React re-renders automatically as new data arrives

With @defer, the server sends the initial result immediately, then pushes deferred fragments as multipart HTTP chunks. Users see fast data instantly and slow data fills in without a loading spinner for the whole page.

Queries with a mix of fast and slow fields where the slow fields should not block initial render