GraphQL Directives
GraphQL directives are annotations such as @include(if: $flag) or @deprecated that attach metadata and behavior to schemas, fields, or operations. Built-in directives control conditional selection; custom directives can enforce authorization, format scalars, or signal federation keys, influencing what data resolves and what reaches the client.
Technical Architecture & Deep-Dive
Clients pass variables that flip @include and @skip to omit expensive branches without maintaining separate query documents. Server schemas declare custom directives consumed by resolver middleware or stitching gateways.
At the edge, allowlisted directives prevent clients from enabling debug fields in production. Transform steps can strip unknown directives before forwarding to upstream GraphQL providers that reject unfamiliar annotations.
Key Architectural Benefits
Implement GraphQL Directives at the Edge
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Frequently Asked Questions
Q:Can directives replace GraphQL fragments?
No. Fragments define reusable selections. Directives modify how those selections resolve or whether they run.
Related Architecture Concepts
GraphQL fragments are named, reusable sets of fields you embed in queries and mutations so multiple operations share the same selection shape. Fragments keep client queries DRY, align codegen output across screens, and make it easier for gateways to recognize consistent field lists when slimming upstream responses.
GraphQL is a query language and runtime for APIs in which clients send a query describing exactly the fields they need, and the server returns JSON matching that shape. A strongly typed schema defines available data, and a single endpoint replaces many REST routes.
Field masking is the technique of applying a list of allowed or excluded field paths to an API response so only selected properties are returned. Masks can be allowlists that keep named fields or denylists that remove sensitive or unnecessary ones.