Is Magento's GraphQL API complete enough for headless?

For 80% of storefront features, yes. Adobe’s GraphQL covers products, categories, cart, checkout, customer, orders, search, CMS pages, URL rewrites, store config. The 20% gap typically:

• Custom EAV attributes (we add resolvers)
• B2B queries (companies, quotes, requisition lists, partial in Adobe Commerce)
• Custom checkout fields / extension data
• Third-party extension data (loyalty, reviews from non-native sources, custom recommendations)

Our audit catalogues every gap on your store and quotes the resolver work. GraphQL Mesh stitches Magento’s GraphQL with Algolia / contentful / your ERP into one schema. We document the full schema as part of every build.