Directives
Configure GraphQL types, fields, and arguments
Looking for Apollo Federation directives? See Federation-specific GraphQL directives.
A directive decorates part of a GraphQL schema or operation with additional configuration. Tools like Apollo Server (and Apollo Client) can read a GraphQL document's directives and perform custom logic as appropriate.
Directives are preceded by the @ character, like so:
1type ExampleType {
2 oldField: String @deprecated(reason: "Use `newField`.")
3 newField: String
4}This example shows the @deprecated directive, which is a default directive (i.e., it's part of the GraphQL specification). It demonstrates the following about directives:
Directives can take arguments of their own (
reasonin this case).Directives appear after the declaration of what they decorate (the
oldFieldfield in this case)
Valid locations
Each directive can only appear in certain locations within a GraphQL schema or operation. These locations are listed in the directive's definition.
For example, here's the GraphQL spec's definition of the @deprecated directive:
1directive @deprecated(
2 reason: String = "No longer supported"
3) on FIELD_DEFINITION | ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION | ENUM_VALUEThis indicates that @deprecated can decorate any of the four listed locations. Also note that its reason argument is optional and provides a default value. Usage examples of each location are provided below:
1# ARGUMENT_DEFINITION
2# Note: @deprecated arguments _must_ be optional.
3directive @withDeprecatedArgs(
4 deprecatedArg: String @deprecated(reason: "Use `newArg`"),
5 newArg: String
6) on FIELD
7
8type MyType {
9 # ARGUMENT_DEFINITION (alternate example on a field's args)
10 fieldWithDeprecatedArgs(name: String! @deprecated): String
11 # FIELD_DEFINITION
12 deprecatedField: String @deprecated
13}
14
15enum MyEnum {
16 # ENUM_VALUE
17 OLD_VALUE @deprecated(reason: "Use `NEW_VALUE`.")
18 NEW_VALUE
19}
20
21input SomeInputType {
22 nonDeprecated: String
23 # INPUT_FIELD_DEFINITION
24 deprecated: String @deprecated
25}If @deprecated appears elsewhere in a GraphQL document, it produces an error.
If you create a custom directive, you need to define it (and its valid locations) in your schema. You don't need to define default directives like
@deprecated.
Schema directives vs. operation directives
Usually, a given directive appears exclusively in GraphQL schemas or exclusively in GraphQL operations (rarely both, although the spec allows this).
For example, among the default directives, @deprecated is a schema-exclusive directive and @skip and @include are operation-exclusive directives.
The GraphQL spec lists all possible directive locations. Schema locations are listed under TypeSystemDirectiveLocation, and operation locations are listed under ExecutableDirectiveLocation.
Default directives
The GraphQL specification defines the following default directives:
| Directive | Description |
|---|---|
@deprecated(reason: String) | Marks the schema definition of a field or enum value as deprecated with an optional reason. |
@skip(if: Boolean!) | If true, the decorated field or fragment in an operation is not resolved by the GraphQL server. |
@include(if: Boolean!) | If false, the decorated field or fragment in an operation is not resolved by the GraphQL server. |