This API Management solution will be deprecated in the February 2021, 4.24 SnapLogic release.

SnapLogic Documentation > Using the Request and Response Transformer in your API Proxy > Proxy_APIM_Deprecated.png

Starting with the 4.23 Release (November 2020), we recommend that you use the Native API Manager, which allows you to manage your Triggered and Ultra Tasks as APIs without having to bundle them in Proxies.

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Overview

Request and response transformations enable you to modify the contents of your Proxy APIs using key/value pairs. To do so, you can apply the following API Policies:

Request transformation: Use this policy to transform a header, body, or the query string in the API call before it is forwarded to the Proxy API endpoint.
Response transformation: Use this policy to transform a header or JSON content in the API response that is returned to the caller.

These policies support different operations, which you can apply to different parts of the Proxy API. Depending on the operation type, you can modify the header, query string, or body of the Proxy API.

Supported Operation Types

You can perform the following operations when applying the transformation policy:

Add key/value pairs
Append a key/value pair to an existing key/value pair
Remove a key/value pair
Rename an existing key
Replace a key/value pair

Order of Operations

The following table lists the order of operations for requests and response transformations:

Order	Request Transformer	Response Transformer
1	Remove	Remove
2	Rename	Replace
3	Replace	Add
4	Add	Append
5	Append	N/A

Request and Response Header transformations occur before the Pipeline is executed, so in the case of in Triggered Tasks, any custom HTTP headers or other arguments passed through Pipeline Parameters occur afterward.

Limitations

You cannot apply transformations to the Authorization header of a request.

Transform Requests

You can transform contents in the API requests for the following situations:

To obfuscate sensitive information in the endpoint, like a data key, from the API consumer.
To swap an existing bearer token with a new one.
To pass Pipeline parameters to an API that does not support the parameters in the body.

This operation is not viewable in the Developer Portal or API Manager.

Transform Responses

You can transform contents in the API responses for the following situations:

To add parameters for clarifying information.
To expose the original query string to the consumer.
To rename or replace sensitive content (like data keys or bearer tokens) not intended to be viewed by the API consumer.

Examples

The following image shows the Proxy API, without a response transformation, after it has been executed in the Developer Portal.

SnapLogic Documentation > Using the Request and Response Transformer in your API Proxy > APIM_proxy_ResponseNotTransformed.png

The following image shows the Response Transformer being set to add the content-type key totalNumbers to the header:

SnapLogic Documentation > Using the Request and Response Transformer in your API Proxy > APIM_Policies_ResponseTransformer.png

The following image shows the content-type key totalNumbers added to the response header after the Proxy is executed in the Developer Portal through the Try it functionality.

SnapLogic Documentation > Using the Request and Response Transformer in your API Proxy > APIM_proxy_ResponseTransformed.png