---
title: Response message
slug: product-recommendations/docs/response-message-1
docTags: 
createdAt: 2026-07-30T20:41:31.037Z
---

The response message has the following properties:

| Name           |           |       | Description and usage                                                                                                                                                                                                                                                                                                                                                                                                                              |
| -------------- | --------- | ----- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| status         |           |       | The status of the request as one of the following:<br />**Note**: If a fail status is returned, a fatal error occurred, and the request could not be fulfilled and recommendations are not included in the response.<br />- OK. A successful request.<br />- fail. An error occurred.<br />- warning. Errors were found but a useful result was still returned.                                                                                    |
| pageTrackingId |           |       | Unique identifier of the tracking page.<br />For use with [Personalized Search & Navigation](/epiui/CMS/Content/documentation/developer-guides/search-navigation/Integration/personalized-search-navigation,,176277/?epieditmode=False) only.<br />Used to track any future information or user event on this page. For example, a selected facet on a Search Results page.<br />**Note**: Available from version 1.3 of the Server-to-Server API. |
| errors         |           |       | Shown if status is fail or warning.                                                                                                                                                                                                                                                                                                                                                                                                                |
|                | code      |       | The type of error. See [Error codes](docId\:ka4QWM16BR0f2Lk-QaLaj).                                                                                                                                                                                                                                                                                                                                                                                |
|                | message   |       | Explanation with debug information that may contain advice about how to solve the error.                                                                                                                                                                                                                                                                                                                                                           |
| session        |           |       | Shown if status is OK.                                                                                                                                                                                                                                                                                                                                                                                                                             |
|                | session   |       | Allocated ID of Optimizely session established with the tracker.                                                                                                                                                                                                                                                                                                                                                                                   |
|                | cuid      |       | Consolidated value of the user ID.                                                                                                                                                                                                                                                                                                                                                                                                                 |
| info           |           |       | Click information.<br />Displayed only if click information was provided in the request. An array of the Optimizely products given in the request. Available values are smartRecs and smartContent.                                                                                                                                                                                                                                                |
|                | smartRecs |       | An array of click information for Optimizely Product Recommendations.                                                                                                                                                                                                                                                                                                                                                                              |
|                |           | click | \[String]<br />Confirmation that the click was successful.                                                                                                                                                                                                                                                                                                                                                                                         |
|                |           | id    | \[64-bit number]<br />The ID of the Optimizely product recommendation. For example, "id": 5637282.                                                                                                                                                                                                                                                                                                                                                 |

## Failure response

If status is fail or warning, an errors element is returned after the status property. The value is a list of errors or warnings encountered. Failure response example.

```csharp
{
      "status" : "fail",
      "errors" : [
        {  
          "code"    : "MalformedJson",
          "message" : "Json Parsing exception: Malformed JSON. Unexpected character ('{' (code 123)): was expecting double-quote to start field name at character offset 1."
        }
      ]
    }
```

## Successful response

If the status is not fail, the session element is returned containing the current cuid session and pageTrackingId. These are string values, which contain a mix of alphanumeric and special characters.

```csharp
{
      "status"         : "OK",
      "pageTrackingId" : "523863900/4ubJYHs6gwcwUz9xCjCmng",
      "session"        : {
        "session" : "123456789012|a1b2c3d4e5A6B7C8D9E0f1g2h3i4j5F1G2H3I4J5k1l",
        "cuid"    : "09876543210|Z0Y9X8W7V6z5y4x3w2v1U0T9S8R7Q6u5t4s3r2q1P0O"
      }
    }
```

Store the cuid in persistent storage and send it to Optimizely in future requests so the same customer can be tracked across multiple sessions (see [Storing customer IDs](https://world.optimizely.com/documentation/developer-guides/personalization/integration-guides/server-to-server-api/storing-customer-ids/)).

The rest of the response includes the appropriate response considering the information of the track and the client tailored customization for the site.