# December 19, 2024 - LWM2M Opaque type serialization to byte array is now deprecated

**URL:** <https://community.cumulocity.com/t/december-19-2024-lwm2m-opaque-type-serialization-to-byte-array-is-now-deprecated/11987>\
**Category:** Device Management & connectivity\
**Tags:** Announcement, device-management, lwm2m, device-connectivity\
**Created:** [March 17, 2025, 8:54am UTC](https://community.cumulocity.com/t/december-19-2024-lwm2m-opaque-type-serialization-to-byte-array-is-now-deprecated/11987 "2025-03-17T08:54:55Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![system](https://dub1.discourse-cdn.com/flex005/user_avatar/community.cumulocity.com/system/32/31990_2.png) [@system](https://community.cumulocity.com/u/system)\
**Post date:** [March 17, 2025, 8:54am UTC](https://community.cumulocity.com/t/december-19-2024-lwm2m-opaque-type-serialization-to-byte-array-is-now-deprecated/11987/1 "2025-03-17T08:54:55Z")

</div>

## Context

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**Change Type:** Announcement  
**Product area:** Device management & connectivity  
**Component:** LWM2M  
**Deployed at:** [eu.latest.cumulocity.com](http://eu.latest.cumulocity.com), [apj.cumulocity.com](http://apj.cumulocity.com), [jp.cumulocity.com](http://jp.cumulocity.com), [cumulocity.com](http://cumulocity.com), [us.cumulocity.com](http://us.cumulocity.com)

> **Technical details**
>
> **Build artifact:** lwm2m-agent (10.20.440.0)  
> **Internal ID:** DM-4179

## Description

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By default, the LWM2M service serializes binary data of a resource such as Opaque type to a byte array in Cumulocity representations. This functionality is now deprecated and will be changed in the future to the hexadecimal string format. For now the default serializer is still serialized to the byte array and the format can be switched only on the instance level.  
This change affects the way the data is represented in Cumulocity objects (operations, values displayed in the **Objects** tab). It does not affect the communication with LWM2M devices.