OpenThread Version 2.7.0 (June 16, 2025) - Release Notes#

Simplicity SDK Version 2025.6.0

The OpenThread SDK is an enhanced version of the open-source OpenThread implementation released by Google that has been tailored to work with Silicon Labs hardware.

Click here for earlier releases.

Release Summary#

Impact of Release Changes#

Impact Statements | Migration Guide

Impact Statements#

Migration Guide#

• sl_main migration:

  • It is recommended to perform a manual upgrade of RTOS based applications.

  • See the sl_system to sl_main migration guide for detailed instructions.

  • Learn more about using sl_system_compatibility in baremetal applications here.

• openthread stack update

  • Due to an upstream change in the OpenThread codebase, projects based on the sleepy-demo scenario (sleepy-demo-mtd, sleepy-demo-ftd, sleepy-demo-ssed) require a manual change to update the OT_NETIF_THREAD macro to OT_NETIF_THREAD_INTERNAL. This will need to be modified in the sleepy-demo-mtd.c, sleepy-demo-ftd.c, and sleepy-demo-ssed.c located in the project root directory.

Using This Release#

What's in the Release? | Compatible Software | Installation and Use | Help and Feedback

What's in the Release?#

This release contains the following

• Silicon Labs OpenThread stack

• Silicon Labs OpenThread sample applications

• Silicon Labs OpenThread border router

Compatible Software#

Installation and Use#

The OpenThread SDK is part of the Simplicity SDK, the suite of Silicon Labs SDKs. To quickly get started with OpenThread and the Simplicity SDK, start by installing Simplicity Studio 5, which will set up your development environment and walk you through Simplicity SDK installation. Simplicity Studio 5 includes everything needed for IoT product development with Silicon Labs devices, including a resource and project launcher, software configuration tools, full IDE with GNU toolchain, and analysis tools. Installation instructions are provided in the online Simplicity Studio 5 User’s Guide.

Alternatively, Simplicity SDK may be installed manually by downloading or cloning the latest from GitHub. See https://github.com/SiliconLabs/simplicity_sdk for more information.

The GSDK default installation location has changed beginning with Simplicity Studio 5.3.

• Windows: C:\Users\<NAME>\SimplicityStudio\SDKs\simplicity_sdk

• MacOS: /Users/<NAME>/SimplicityStudio/SDKs/simplicity_sdk

Documentation specific to the SDK version is installed with the SDK. API references and other information about this release are available on https://docs.silabs.com/openthread/latest/. Select your SDK version in the upper right.

For more information about the OpenThread SDK see QSG170: Silicon Labs OpenThread QuickStart Guide.

If you are new to Thread see UG103.11: Thread Fundamentals.

To review Security and Software Advisory notifications and manage your notification preferences:

1. Go to https://community.silabs.com/.

2. Log in with your account credentials.

3. Click your profile icon in the upper-right corner of the page.

4. Select Notifications from the dropdown menu.

5. In the Notifications section, go to the My Product Notifications tab to review historical Security and Software Advisory notifications

6. To manage your preferences, use the Manage Notifications tab to customize which product updates and advisories you receive.

To learn more about the software in this release, dive into our online documentation.

Additional Information#

• OpenThread GitHub Repository

  The Silicon Labs OpenThread SDK includes all changes from the OpenThread GitHub repo https://github.com/openthread/openthread up to and including commit fb0446f53. An enhanced version of the OpenThread repo can be found in the following Simplicity Studio 5 GSDK location: <GSDK Installation Location>\util\third_party\openthread

• OpenThread Border Router GitHub Repository

  The Silicon Labs OpenThread SDK includes all changes from the OpenThread border router GitHub repo https://github.com/openthread/ot-br-posix up to and including commit 622f5ecfc. An enhanced version of the OpenThread border router repo can be found in the following Simplicity Studio 5 GSDK location: <GSDK Installation Location>\util\third_party\ot-br-posix

• Using the Border Router

  For ease of use, Silicon Labs recommends the use of a Docker container for your OpenThread border router. Refer to AN1256: Using the Silicon Labs RCP with the OpenThread Border Router for details on how to set up the correct version of OpenThread border router Docker container. It is available at https://hub.docker.com/r/siliconlabsinc/openthread-border-router. If you are manually installing a border router, using the copies provided with the Silicon Labs OpenThread SDK, refer to AN1256: Using the Silicon Labs RCP with the OpenThread Border Router for more details. Although updating the border router environment to a later GitHub version is supported on the OpenThread website, it may make the border router incompatible with the OpenThread RCP stack in the SDK.

• Secure Vault Integration

  When deployed to Secure Vault High devices, sensitive keys are protected using the Secure Vault Key Management functionality. The following table shows the protected keys and their storage protection characteristics.

  Wrapped keys that are marked as “Non-Exportable” can be used but cannot be viewed or shared at runtime.

  Wrapped keys that are marked as “Exportable” can be used or shared at runtime but remain encrypted while stored in flash.

  For more information on Secure Vault Key Management functionality, see AN1271: Secure Key Storage.

• Thread Certification

  This release has been qualified for Thread 1.4 compliance for the SoC with ongoing compliance testing for the Host-RCP architecture using the Thread Test Harness v62.0 Patch-3 (latest available Member Release). Some of the Border Router test cases relevant to the Host-RCP architecture are still being finalized. For more inputs and guidance on OpenThread Border Router certification please reach out to the Silicon Labs support team, as coverage on certain test cases may have to be excluded or additional qualification might be needed with newer versions of the Test Harness. For this release Silicon Labs recommends using the above TH version for qualification. Also included with this release is a set of OpenThread stack libraries that may be used for Thread certification by inheritance.

Help and Feedback#

• Contact Silicon Labs Support.

• To use our Ask AI tool to get answers, see the search field at the top of this page.

  Note: Ask AI is experimental.

• Get help from our developer community.

Feature Matrix#

Supported Features | Unsupported Features

Supported Features#

Unsupported Features#

This release includes support for running the OpenThread Border Router in a HOST / NCP architecture. However, at the time of the release, the following features were not complete when using this achitecture: TREL, NAT64, DHCPv6.

SDK Release and Maintenance Policy#

See our SDK Release and Maintenance Policy.