Integrating API Gateway to Amazon Translate

openapi.yaml

openapi: 3.0.0
info:
  title: AWS Service Integration API
  version: 1.0.0

paths: 
  /translations:
    post:
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/translateText'
      responses:
        200:
          $ref: '#/components/responses/ok'
      x-amazon-apigateway-request-validator: Validate All
      x-amazon-apigateway-integration:
        credentials:
          Fn::Sub: ${TranslateTextRole.Arn}
        uri:
          Fn::Sub: arn:${AWS::Partition}:apigateway:${AWS::Region}:translate:path/${AWS::AccountId}
        httpMethod: POST
        type: aws
        passthroughBehavior: never
        requestParameters:
          integration.request.header.Content-Type: "'application/x-amz-json-1.1'"
          integration.request.header.X-Amz-Target: "'AWSShineFrontendService_20170701.TranslateText'"
        requestTemplates:
          application/json: |
            {
              "SourceLanguageCode": "en",
              "TargetLanguageCode": "es",
              "Text": "$input.path('$.text')"
            }
        responses:
          200:
            statusCode: 200
            responseTemplates:
              application/json: |
                {
                   "translatedText": "$input.path('$.TranslatedText')"
                }

components:
  schemas:
    translateText:
      type: object
      required:
        - text
      properties:
        text: 
          type: string

  responses:
    ok:
      content:
        application/json:
          schema:
            type: object
            required:
              - translatedText
            properties:
              translatedText:
                type: string

template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  Example template to show how to integrate an AWS service to API Gateway

Resources:
  Api:
    Type: AWS::Serverless::Api
    Properties:
      TracingEnabled: false
      StageName: dev
      DefinitionBody:
        Fn::Transform:
          Name: AWS::Include
          Parameters:
            Location: ./openapi.yaml 

  TranslateTextRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - apigateway.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: TranslateTextPolicy
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - translate:TranslateText
                Resource: '*'