---
title: "Validation and feedback"
slug: "product-catalog-api-validation-and-feedback"
updated: 2026-05-29T13:38:33Z
published: 2026-05-29T13:38:33Z
canonical: "docs.mapp.com/product-catalog-api-validation-and-feedback"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mapp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Validation and feedback

The Product Catalog API validates incoming data before and during processing. Validation helps identify invalid requests and provides feedback about accepted, skipped, or failed data.

---

## Validation process

Validation consists of two stages.

| Validation stage | Purpose |
| --- | --- |
| Initial validation | Performs synchronous validation before the request is accepted for processing. |
| Final validation | Performs asynchronous validation during later processing stages. |

---

## Initial validation

Initial validation is performed synchronously when the API request is received.

### Critical errors

If a critical validation error occurs:

- The request is rejected immediately.
- A detailed error message is returned in the HTTP response.

If no critical error is detected:

- The request is accepted for processing.
- A `201 Created` response is returned.
- A unique `event_id` is assigned to the request.

The `event_id` uniquely identifies the request throughout its processing lifecycle and can be used for troubleshooting, support requests, and correlating processing results.

### Partial update validation

PATCH operations perform additional validation for incoming attributes, including:

- Attribute existence
- Attribute data type validation
- Attribute-specific validation rules as described in the attribute definition documentation

If an attribute fails validation:

- The invalid attribute is skipped.
- Valid attributes continue processing.

The response indicates which attributes were accepted and which were skipped.

---

## Final validation

Final validation is performed asynchronously during later processing stages.

Examples include:

- Validation of mandatory attributes
- Additional business rule validation

If validation fails during asynchronous processing:

- The failure is logged internally.
- The associated `event_id` is included in the feedback.
- A webhook notification can be sent to configured callback URLs.

---

## Event identifiers

Successful requests return a unique `event_id`.

Store this identifier whenever possible. It can be used to:

- Trace processing results
- Investigate failures
- Correlate webhook notifications with API requests
- Support troubleshooting activities

---

## Validation feedback in responses

Responses can contain information about accepted and skipped data.

| Response field | Description |
| --- | --- |
| `accepted_attributes` | Attributes accepted for processing. |
| `skipped_attributes` | Attributes skipped during processing. |
| `event_id` | Unique identifier assigned to the request event. |
| `operation_id` | Identifier assigned to bulk operations. |