AppsyncFunction L2 construct

AppSync Functions are local functions that perform certain operations onto a backend data source.

Developers can compose operations (Functions) and execute them in sequence with Pipeline Resolvers.

CloudFormation: AWS::AppSync::FunctionConfiguration
L1 type: CfnFunctionConfiguration
Source: aws-appsync/lib/appsync-function.ts
Type last changed: v2.234.0 · 8 Jan 2026

Example

declare const api: appsync.GraphqlApi;

const appsyncFunction = new appsync.AppsyncFunction(this, 'function', {
  name: 'appsync_function',
  api,
  dataSource: api.addNoneDataSource('none'),
  requestMappingTemplate: appsync.MappingTemplate.fromFile('request.vtl'),
  responseMappingTemplate: appsync.MappingTemplate.fromFile('response.vtl'),
});

python

# api: appsync.GraphqlApi


appsync_function = appsync.AppsyncFunction(self, "function",
    name="appsync_function",
    api=api,
    data_source=api.add_none_data_source("none"),
    request_mapping_template=appsync.MappingTemplate.from_file("request.vtl"),
    response_mapping_template=appsync.MappingTemplate.from_file("response.vtl")
)

java

GraphqlApi api;


AppsyncFunction appsyncFunction = AppsyncFunction.Builder.create(this, "function")
        .name("appsync_function")
        .api(api)
        .dataSource(api.addNoneDataSource("none"))
        .requestMappingTemplate(MappingTemplate.fromFile("request.vtl"))
        .responseMappingTemplate(MappingTemplate.fromFile("response.vtl"))
        .build();

csharp

// Install: dotnet add package Amazon.CDK.Lib
GraphqlApi api;


var appsyncFunction = new AppsyncFunction(this, "function", new AppsyncFunctionProps {
    Name = "appsync_function",
    Api = api,
    DataSource = api.AddNoneDataSource("none"),
    RequestMappingTemplate = MappingTemplate.FromFile("request.vtl"),
    ResponseMappingTemplate = MappingTemplate.FromFile("response.vtl")
});

// Install: go get github.com/aws/aws-cdk-go/awscdk/v2
var api GraphqlApi


appsyncFunction := appsync.NewAppsyncFunction(this, jsii.String("function"), &AppsyncFunctionProps{
	Name: jsii.String("appsync_function"),
	Api: Api,
	DataSource: api.AddNoneDataSource(jsii.String("none")),
	RequestMappingTemplate: appsync.MappingTemplate_FromFile(jsii.String("request.vtl")),
	ResponseMappingTemplate: appsync.MappingTemplate_*FromFile(jsii.String("response.vtl")),
})

Initializer

new AppsyncFunction(scope: Construct, id: string, props: AppsyncFunctionProps)

python

AppsyncFunction(scope: Construct, id: str, props: AppsyncFunctionProps)

java

new AppsyncFunction(Construct scope, String id, AppsyncFunctionProps props)

csharp

new AppsyncFunction(Construct scope, string id, AppsyncFunctionProps props)

NewAppsyncFunction(Scope Construct, Id *string, Props AppsyncFunctionProps)

Construct Props

apiIGraphqlApiapiIGraphqlApiapiIGraphqlApiApiIGraphqlApiApiIGraphqlApirequired#

the GraphQL Api linked to this AppSync Function.

codeCodecodeCodecodeCodeCodeCodeCodeCode= no code is used#

The function code.

dataSourceBaseDataSourcedata_sourceBaseDataSourcedataSourceBaseDataSourceDataSourceBaseDataSourceDataSourceBaseDataSourcerequired#

the data source linked to this AppSync Function.

descriptionstringdescriptionstrdescriptionStringDescriptionstringDescription*string= no description#

the description for this AppSync Function.

maxBatchSizenumbermax_batch_sizeint | floatmaxBatchSizeNumberMaxBatchSizedoubleMaxBatchSize*float64= No max batch size#

The maximum number of resolver request inputs that will be sent to a single AWS Lambda function in a BatchInvoke operation.

Can only be set when using LambdaDataSource.

namestringnamestrnameStringNamestringName*stringrequired#

the name of the AppSync Function.

requestMappingTemplateMappingTemplaterequest_mapping_templateMappingTemplaterequestMappingTemplateMappingTemplateRequestMappingTemplateMappingTemplateRequestMappingTemplateMappingTemplate= no request mapping template#

the request mapping template for the AppSync Function.

responseMappingTemplateMappingTemplateresponse_mapping_templateMappingTemplateresponseMappingTemplateMappingTemplateResponseMappingTemplateMappingTemplateResponseMappingTemplateMappingTemplate= no response mapping template#

the response mapping template for the AppSync Function.

runtimeFunctionRuntimeruntimeFunctionRuntimeruntimeFunctionRuntimeRuntimeFunctionRuntimeRuntimeFunctionRuntime= no function runtime, VTL mapping…#

The functions runtime.

default

Default: no function runtime, VTL mapping templates used

Properties

dataSourceBaseDataSourcedata_sourceBaseDataSourcedataSourceBaseDataSourceDataSourceBaseDataSourceDataSourceBaseDataSourcerequired#

the data source of this AppSync Function.

envResourceEnvironmentenvResourceEnvironmentenvResourceEnvironmentEnvResourceEnvironmentEnvResourceEnvironmentrequired#

The environment this resource belongs to.

notes

For resources that are created and managed in a Stack (those created by creating new class instances like new Role(), new Bucket(), etc.), this is always the same as the environment of the stack they belong to.

For referenced resources (those obtained from referencing methods like Role.fromRoleArn(), Bucket.fromBucketName(), etc.), they might be different than the stack they were imported into.

functionArnstringfunction_arnstrfunctionArnStringFunctionArnstringFunctionArn*stringrequired#

the ARN of the AppSync function.

functionConfigurationRefFunctionConfigurationReferencefunction_configuration_refFunctionConfigurationReferencefunctionConfigurationRefFunctionConfigurationReferenceFunctionConfigurationRefFunctionConfigurationReferenceFunctionConfigurationRefFunctionConfigurationReferencerequired#

A reference to a FunctionConfiguration resource.

functionIdstringfunction_idstrfunctionIdStringFunctionIdstringFunctionId*stringrequired#

the ID of the AppSync function.

functionNamestringfunction_namestrfunctionNameStringFunctionNamestringFunctionName*stringrequired#

the name of this AppSync Function.

nodeNodenodeNodenodeNodeNodeNodeNodeNoderequired#

The tree node.

PROPERTY_INJECTION_IDstringproperty_injection_idstrPROPERTY_INJECTION_IDStringPROPERTY_INJECTION_IDstringPROPERTY_INJECTION_ID*stringrequiredstatic#

Uniquely identifies this class.

stackStackstackStackstackStackStackStackStackStackrequired#

The stack in which this resource is defined.

Methods

applyCrossStackReferenceStrength(strength: ReferenceStrength): voiddef apply_cross_stack_reference_strength(self, strength: ReferenceStrength) -> Nonepublic void applyCrossStackReferenceStrength(ReferenceStrength strength)public void ApplyCrossStackReferenceStrength(ReferenceStrength strength)func ApplyCrossStackReferenceStrength(Strength ReferenceStrength)#

Override the cross-stack reference strength for this resource.

notes · 1 parameter

When set, any cross-stack reference to this resource will use the specified mechanism instead of the global default determined by the @aws-cdk/core:defaultCrossStackReferences context key. This is useful for selectively weakening specific references to avoid the "deadly embrace" problem without changing the app-wide default.

Parameters

strengthstrengthstrengthstrengthStrength — - The reference strength to use for this resource.

applyRemovalPolicy(policy: RemovalPolicy): voiddef apply_removal_policy(self, policy: RemovalPolicy) -> Nonepublic void applyRemovalPolicy(RemovalPolicy policy)public void ApplyRemovalPolicy(RemovalPolicy policy)func ApplyRemovalPolicy(Policy RemovalPolicy)#

Apply the given removal policy to this resource.

notes

The Removal Policy controls what happens to this resource when it stops being managed by CloudFormation, either because you've removed it from the CDK application or because you've made a change that requires the resource to be replaced.

The resource can be deleted (RemovalPolicy.DESTROY), or left in your AWS account for data recovery and cleanup later (RemovalPolicy.RETAIN).

fromAppsyncFunctionAttributes(scope: Construct, id: string, attrs: AppsyncFunctionAttributes): IAppsyncFunction

@staticmethod def from_appsync_function_attributes(scope: Construct, id: str, attrs: AppsyncFunctionAttributes) -> IAppsyncFunction

public static IAppsyncFunction fromAppsyncFunctionAttributes(Construct scope, String id, AppsyncFunctionAttributes attrs)

public static IAppsyncFunction FromAppsyncFunctionAttributes(Construct scope, string id, AppsyncFunctionAttributes attrs)

func FromAppsyncFunctionAttributes(Scope Construct, Id *string, Attrs AppsyncFunctionAttributes) IAppsyncFunctionstatic#

Import Appsync Function from arn.

isConstruct(x: any): boolean@staticmethod def is_construct(x: Any) -> boolpublic static Boolean isConstruct(Object x)public static bool IsConstruct(object x)func IsConstruct(X interface{}) *boolstatic#

Checks if `x` is a construct.

notes · 1 parameter · returns

Use this method instead of instanceof to properly detect Construct instances, even when the construct library is symlinked.

Explanation: in JavaScript, multiple copies of the constructs library on disk are seen as independent, completely different libraries. As a consequence, the class Construct in each copy of the constructs library is seen as a different class, and an instance of one class will not test as instanceof the other class. npm install will not create installations like this, but users may manually symlink construct libraries together or use a monorepo tool: in those cases, multiple copies of the constructs library can be accidentally installed, and instanceof will behave unpredictably. It is safest to avoid using instanceof, and using this type-testing method instead.

Parameters

xxxxX — Any object.

Returns: true if x is an object created from a class which extends Construct.

isOwnedResource(construct: IConstruct): boolean@staticmethod def is_owned_resource(construct: IConstruct) -> boolpublic static Boolean isOwnedResource(IConstruct construct)public static bool IsOwnedResource(IConstruct construct)func IsOwnedResource(Construct IConstruct) *boolstatic#

Returns true if the construct was created by CDK, and false otherwise.

isResource(construct: IConstruct): boolean@staticmethod def is_resource(construct: IConstruct) -> boolpublic static Boolean isResource(IConstruct construct)public static bool IsResource(IConstruct construct)func IsResource(Construct IConstruct) *boolstatic#

Check whether the given construct is a Resource.

toString(): stringdef to_string(self, ) -> strpublic String toString()public string ToString()func ToString() *string#

Returns a string representation of this construct.

with(...mixins: IMixin[]): IConstructdef with(self, mixins: IMixin) -> IConstructpublic IConstruct with(IMixin mixins)public IConstruct With(IMixin mixins)func With(Mixins IMixin) IConstruct#

Applies one or more mixins to this construct.

Mixins are applied in order. The list of constructs is captured at the start of the call, so constructs added by a mixin will not be visited. Use multiple with() calls if subsequent mixins should apply to added constructs.

AppsyncFunction L2 construct ​

Example ​

Initializer ​

Construct Props ​

Properties ​

Methods ​