The OpenThread project published OpenThread Border Router (ot-br-posix) v2026.11.0 on 1 November 2026. This is the open-source border router that many Thread setups run underneath, including Home Assistant's OpenThread Border Router add-on and plenty of DIY builds on a Raspberry Pi with a radio co-processor. The monthly release has two changes worth knowing about, plus a batch of mDNS fixes and work toward running the agent on macOS.

REST API without an open TCP port

otbr-agent exposes a REST API that other software uses to read and manage the Thread network. Until now it always listened on an IP address and port. Starting with this release, if the --rest-listen-address value begins with /, the agent treats it as a Unix socket path and listens there instead. Any address that is not a path behaves exactly as before.

The pull request explains the reasoning. When the only REST client runs on the same machine, a listening TCP port is attack surface that has no reason to exist, and a socket file gets ordinary filesystem permissions on top. The author names the motivating case directly: packaging otbr-agent next to a Home Assistant install on an appliance-style device, where Home Assistant's otbr integration is the only client. The change is about 20 lines and adds no new dependency.

Nothing switches over automatically. Existing installs keep the TCP listener until whoever packages or configures the agent decides to use a socket path.

Thread 1.4.1 route data in network diagnostics

The REST API can now request the Enhanced Route TLV (TLV 37), which Thread 1.4.1 added to network diagnostics. It shows up as enhancedRoute in /api/diagnostics and in network diagnostic tasks. For each router it lists the route ID, whether that entry is the reporting router itself, the link quality in each direction and the next hop with its cost. End devices leave the TLV out of their replies, so the field is optional.

For anyone building a Thread map or debugging a flaky mesh, this is the raw material: it shows which routers can hear each other and how traffic gets from one to another. Tools only benefit once they start asking for the new field.

Other changes

  • With several -B infrastructure interfaces, for example Ethernet and Wi-Fi, the agent now chooses one based on link state on every platform, not only Linux. This is part of ongoing macOS host support.
  • The mDNSResponder backend no longer loses a resolved service when it retries an address lookup.
  • DNS-SD subscriptions now run on the interface named in each request. Before, a reply arriving first on a different interface, such as loopback on macOS, could be dropped and leave a Thread device's DNS-SD query to time out after 6 seconds.

Home users normally get these changes later, when add-on and firmware maintainers move to the new version. The release itself is source code on GitHub.