GraphQL to TypeScript: Automated Code Generation Guide

If you write GraphQL queries by hand and then define TypeScript types separately, you are maintaining two sources of truth that will inevitably drift apart. A renamed field in the schema, a new nullable return type, a deprecated argument -- any of these can silently break your frontend at runtime while the compiler stays quiet. @graphql-codegen eliminates this problem entirely. It reads your GraphQL schema and operations, then generates TypeScript types, typed hooks, and even full SDK clients -- all at build time. This guide walks through the full setup from zero to production-ready code generation. Why Type Safety Matters for GraphQL GraphQL already gives you a typed schema. The problem is that this type information lives on the server. Your TypeScript frontend has no compile-time knowledge of what query GetUser actually returns unless you manually write the corresponding interfaces. Manual typing has three failure modes: Types go stale. The backend adds a field or changes a type. You