Function idempotent

Use this decorator to make your lambda handler itempotent. You need to provide a peristance layer to store the idempotency information. At the moment we only support DynamodbPersistenceLayer.

Example

import {
  DynamoDBPersistenceLayer,
  idempotentLambdaHandler
} from '@aws-lambda-powertools/idempotency';
import type { LambdaInterface } from '@aws-lambda-powertools/commons';

class MyLambdaFunction implements LambdaInterface {
  ⁣@idempotent({ persistenceStore: new DynamoDBPersistenceLayer() })
  async handler(event: unknown, _context: unknown) {
    return "Hello World";
  }
}
export myLambdaHandler new MyLambdaFunction();
export const handler = myLambdaHandler.handler.bind(myLambdaHandler);
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Similar to decoratoring a handler you can use the decorator on any other function.

Example

import {
  DynamoDBPersistenceLayer,
  idempotentFunction
} from '@aws-lambda-powertools/idempotency';
import type { LambdaInterface } from '@aws-lambda-powertools/commons';

class MyClass implements LambdaInterface {
  public async handler(event: unknown, _context: unknown) {
    for(const record of event.records){
      await this.process(record);
    }
  }

  ⁣@idemptent({ persistenceStore: new DynamoDBPersistenceLayer() })
  public async process(record: Record<stiring, unknown>) {
    // do some processing
  }
}
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See

• DynamoDBPersistenceLayer
• https://www.typescriptlang.org/docs/handbook/decorators.html