unable to set api key auth on custom mutation

[dreamorosi]

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• I have searched for duplicate or closed issues and discussions.
• I have read the guide for submitting bug reports.
• I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.

JavaScript Framework

Not applicable

Amplify APIs

GraphQL API

Amplify Version

v6

Amplify Categories

Not applicable

Backend

Amplify Gen 2

Environment information

# Put output below this line

@aws-amplify/backend: ^1.14.0 => 1.14.0 
    @aws-amplify/backend-cli: ^1.4.9 => 1.4.10 
    @aws-amplify/ui-react: ^6.9.1 => 6.9.1 
    @aws-amplify/ui-react-internal:  undefined ()
    @aws-amplify/ui-react-server:  undefined ()
    @types/react: ^19.0.8 => 19.0.8 
    @types/react-dom: ^19.0.4 => 19.0.4 
    @vitejs/plugin-react: ^4.3.4 => 4.3.4 
    aws-amplify: ^6.13.0 => 6.13.0 
    aws-amplify/adapter-core:  undefined ()
    aws-amplify/adapter-core/internals:  undefined ()
    aws-amplify/analytics:  undefined ()
    aws-amplify/analytics/kinesis:  undefined ()
    aws-amplify/analytics/kinesis-firehose:  undefined ()
    aws-amplify/analytics/personalize:  undefined ()
    aws-amplify/analytics/pinpoint:  undefined ()
    aws-amplify/api:  undefined ()
    aws-amplify/api/internals:  undefined ()
    aws-amplify/api/server:  undefined ()
    aws-amplify/auth:  undefined ()
    aws-amplify/auth/cognito:  undefined ()
    aws-amplify/auth/cognito/server:  undefined ()
    aws-amplify/auth/enable-oauth-listener:  undefined ()
    aws-amplify/auth/server:  undefined ()
    aws-amplify/data:  undefined ()
    aws-amplify/data/server:  undefined ()
    aws-amplify/datastore:  undefined ()
    aws-amplify/in-app-messaging:  undefined ()
    aws-amplify/in-app-messaging/pinpoint:  undefined ()
    aws-amplify/push-notifications:  undefined ()
    aws-amplify/push-notifications/pinpoint:  undefined ()
    aws-amplify/storage:  undefined ()
    aws-amplify/storage/s3:  undefined ()
    aws-amplify/storage/s3/server:  undefined ()
    aws-amplify/storage/server:  undefined ()
    aws-amplify/utils:  undefined ()
    aws-cdk: ^2.179.0 => 2.179.0 
    aws-cdk-lib: ^2.179.0 => 2.179.0 
    constructs: ^10.4.2 => 10.4.2 
    react: ^19.0.0 => 19.0.0 (18.3.1)
    react-dom: ^19.0.0 => 19.0.0 (18.3.1)
    react-icons: ^5.4.0 => 5.4.0 
    vite: ^6.1.0 => 6.1.0 

Describe the bug

I have this schema:

const schema = a.schema({
  /*
    Creates a database table for 'Feedback' to store the feedbacks
    submitted through our web application.
  */
  Feedback: a
    .model({
      id: a.id(),
      content: a.string(),
      sentiment: a.string()
    })
    .authorization((allow) => [allow.publicApiKey()]),
  /*
    Create a new 'Execution' type that will be returned by our call
    to the Step Functions workflow.
  */
  Execution: a.customType({
    name: a.string(),
    status: a.string(),
    input: a.string(),
    executionArn: a.string(),
    startDate: a.string(),
    stopDate: a.string(),
    output: a.string(),
  }),
  /*
    Mutation that triggers the synchronous execution of our Step
    Functions workflow.
  */
  executeStateMachine: a
    .mutation()
    .arguments({input: a.string()})
    .returns(a.ref('Execution'))
});

And I am unable to set .authorization((allow) => [allow.publicApiKey()]), on the executeStateMachine mutation.

I am getting this error:

InvalidSchemaError: Custom operation executeStateMachine requires both an authorization rule and a handler reference

Expected behavior

I should be able to set my API Key as authorization to the custom operation without the need of specifying a custom authorization handler and deploy a function.

As a matter of fact, if I go on the AppSync console and manually add @aws_api_key to the schema and deploy it manually, everything works.

This used to work in a previous version of Amplify Gen 2, but at some point it broke.

Reproduction steps

See the code above.

Code Snippet

See above, or look at this aws-samples repo that got broken as result.

Log output

// Put your logs below this line
Uncaught AmplifyError InvalidSchemaError: Custom operation executeStateMachine requires both an authorization rule and a handler reference
    at generateContainerEntry (/Users/aamorosi/Codes/repros/aws-amplify-stepfunctions-example/node_modules/@aws-amplify/backend-data/lib/factory.js:96:19)
    at getOrCompute (/Users/aamorosi/Codes/repros/aws-amplify-stepfunctions-example/node_modules/@aws-amplify/backend/lib/engine/singleton_construct_container.js:30:57)
    at getInstance (/Users/aamorosi/Codes/repros/aws-amplify-stepfunctions-example/node_modules/@aws-amplify/backend-data/lib/factory.js:56:35)
    at <anonymous> (/Users/aamorosi/Codes/repros/aws-amplify-stepfunctions-example/node_modules/@aws-amplify/backend/lib/backend_factory.js:67:61)
    at BackendFactory (/Users/aamorosi/Codes/repros/aws-amplify-stepfunctions-example/node_modules/@aws-amplify/backend/lib/backend_factory.js:64:44)
    at defineBackend (/Users/aamorosi/Codes/repros/aws-amplify-stepfunctions-example/node_modules/@aws-amplify/backend/lib/backend_factory.js:98:21)
    at <anonymous> (/Users/aamorosi/Codes/repros/aws-amplify-stepfunctions-example/amplify/backend.ts:8:17)
    at run (<node_internals>/internal/modules/esm/module_job:268:25)
    --- await ---
    at runEntryPointWithESMLoader (<node_internals>/internal/modules/run_main:138:19)
    at executeUserEntryPoint (<node_internals>/internal/modules/run_main:175:5)
    at <anonymous> (<node_internals>/internal/main/run_main_module:36:49)

aws-exports.js

No response

Manual configuration

No response

Additional configuration

No response

Mobile Device

No response

Mobile Operating System

No response

Mobile Browser

No response

Mobile Browser Version

No response

Additional information and screenshots

No response