What is GraphQL
Key idea:
GraphQL — a query language for APIs + runtime, built by Facebook (2015). A single endpoint /graphql, clients specify which fields to return — no over-fetching / under-fetching like REST. Typed schema. Pros: exact data shape, versionless API. Cons: harder caching (single endpoint), N+1 queries without DataLoader.
Below: details, example, related terms, FAQ.
Details
- Schema: types + queries + mutations + subscriptions
- Query: read, GET-like. Mutation: write. Subscription: websocket for realtime
- Resolvers: functions fetching data per field
- Introspection: schema.json for all fields
- Tooling: GraphiQL (browser playground), Apollo Client/Server, Relay
Example
query GetUser($id: ID!) {
user(id: $id) {
name
email
posts(first: 10) {
title
}
}
}Related Terms
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Frequently Asked Questions
GraphQL vs REST — which is faster?
GraphQL is faster for complex UIs (fewer round-trips). REST — for simple CRUD (better caching).
How to solve the N+1 problem?
DataLoader (Facebook): batching + caching per-request. Or persistent queries + query whitelisting.
Is caching harder than REST?
Yes. REST — HTTP cache by URL. GraphQL — application-level cache by query needed. Apollo Client handles this out of the box.