Manage synchronous calls to async using API Management

Question

I am using API Management in my project to make REST API calls to external API's.
We have one requirement where:

1. Client will call us synchronously and will wait for the response.
2. Our layer/project takes this synchronous call and calls external API: Lets say CreditCheckAPI
3. CreditCheckAPI only accepts asynchronous calls

How can i use API Management so that i can manage synchronous incoming calls with async calls. I have to respond to our caller synchronously.
Please help.

Answer 1

@DevBuster007 You can leverage policies to achieve this and in fact, this sample covers this exact scenario. Here is the same policy for reference.

   <!-- The policy defined in this file demonstrates how to mask an asynchronous API endpoint as if it is an synchronous one. -->  
   <!-- This is useful when modernizing APIs but some clients that call the API cannot be updated to the new behavior. -->  
     
   <!-- API used for this example is an Azure Logic Apps (request/resposne), in which retruns HTTP 202 status code, -->  
   <!-- and location header to retrieve the terminal payload. Retry count and interval is fixed  in this example but can also be customized. -->  
     
   <policies>  
       <inbound>  
           <base />  
       </inbound>  
       <backend>  
           <forward-request />  
       </backend>  
       <outbound>  
           <base />  
           <retry condition="@(((IResponse)context.Variables["var"]).StatusCode == 202)" count="10" interval="30">  
               <send-request mode="new" response-variable-name="var" ignore-error="false">  
                   <set-url>@(context.Response.Headers["location"][0])</set-url>  
                   <set-method>GET</set-method>  
               </send-request>  
           </retry>  
           <return-response response-variable-name="var" />  
       </outbound>  
       <on-error>  
           <base />  
       </on-error>  
   </policies>