Apollo Federation Schema Authoring Apollo Federation enables composing multiple GraphQL APIs (subgraphs) into a unified supergraph. Federation 2 Schema Setup Every Federation 2 subgraph must opt-in via : Import only the directives your subgraph uses. The version shown ( ) is illustrative — check the Federation changelog for currently supported versions before copying it verbatim. A subgraph's version is a floor, not the composition version — see Federation versions for the full explanation. Core Directives Quick Reference | Directive | Purpose | Example | |-----------|---------|---------| | |…