Apollo Client — Industry-Leading GraphQL Client for TS/JS

What Apollo Client Does

• Normalized cache — entities deduped by __typename:id
• Query hooks — useQuery, useMutation, useSubscription, useLazyQuery, useFragment
• Optimistic UI — local cache updates before server confirms
• Pagination — fetchMore with offset or cursor-based
• Local state — client-side schema and resolvers
• SSR — server-rendered queries with hydration
• Subscriptions — GraphQL subscriptions via WebSocket
• Codegen — TypeScript types from schema

Architecture

Queries execute through a link chain (auth, error, retry, http). Responses are normalized into the InMemoryCache. Components subscribe to cache via hooks and re-render on cache changes. Mutations can update cache via refetchQueries, update(), or optimistic responses.

Self-Hosting

Client-only library.

Key Features

• Normalized caching by __typename:id
• Optimistic UI updates
• Pagination helpers
• Local state management
• SSR support
• WebSocket subscriptions
• Apollo DevTools browser extension
• Multi-framework (React, Vue, Angular)
• TypeScript codegen integration

Comparison

FAQ

Q: Apollo vs URQL？ A: Apollo has the most features and the smartest caching, but a larger bundle. URQL is lighter with a simpler API, well-suited to smaller apps.

Q: Can I use it without a GraphQL server? A: Yes. apollo-link-rest wraps REST endpoints as GraphQL, or you can use Apollo's client-side state management for local data.

Q: Do I need codegen? A: Strongly recommended. graphql-codegen generates types from your schema and operations, eliminating runtime type errors.

Sources & Credits

• Docs: https://www.apollographql.com/docs/react
• GitHub: https://github.com/apollographql/apollo-client
• License: MIT