Release v2.1.5 — April 3, 2026

[jnilo1]

⚠️ OTBR REST API compatibility fix for Home Assistant 2026.4+. Upgrade path:

./flash_install_rtl8196e.sh gateway_ip

⚠️ Breaking: OTBR REST API — Home Assistant compatibility

The PascalCase REST API patch introduced in v2.1.3 has been removed. otbr-agent now returns native camelCase, matching upstream ot-br-posix.

otbr-agent version	HA < 2026.4	HA ≥ 2026.4
v2.1.3 / v2.1.4 (PascalCase patch)	✅ OK	❌ "Failed to call OTBR API"
v2.1.5+ (camelCase native)	❌ "Failed to call OTBR API"	✅ OK

Who is affected? Only Thread/OTBR users. Zigbee users are not impacted.

What to do? Update Home Assistant and otbr-agent together. If you must stay on HA < 2026.4, keep the v2.1.3 or v2.1.4 otbr-agent binary.

Why? Upstream ot-br-posix switched to camelCase (commit 2e8ccf2b, Sep 2025). Home Assistant 2026.4 ships python-otbr-api ≥ 2.9.0 which expects camelCase — the old PascalCase patch is now counter-productive.

New feature

• Dropbear SCP & SSH client: scp and dbclient (SSH client) added to the gateway. File transfers no longer require cat | ssh workarounds:

  # From your PC to the gateway:
  scp otbr-agent root@gateway:/userdata/usr/bin/
  
  # From the gateway to your PC (requires dbclient):
  scp root@gateway:/userdata/etc/radio.conf .

  Binary size impact: 473 KB → 555 KB (+82 KB). No runtime overhead — scp and dbclient are only loaded when invoked.

  Credit: @MaxRower (request), @olivluca (solution)

April 4, 2026 Update

The PascalCase REST API patch is kept. See this thread.

Full changelog (April 4, 2026 update)

• RTL8196E CHANGELOG
• EFR32 CHANGELOG

[olivluca]

There must be something wrong (I didn't investigate too much) because I tried flashing it twice and there's no /bin/scp in the device, I do see it in the skeleton.
It's also still reporting 2.1.4 (because you didn't modify motd and version in this commit),

[jnilo1]

It was using the rootfs.bin from the previous run, once deleted it re-generated it and now scp works.

@olivluca The stale rootfs.bin issue you hit should now be fixed — rootfs.bin is always rebuilt from the skeleton before flashing, same as userdata.bin. No more need to manually delete it.

[olivluca]

I flashed the new 2.1.5 but ha still complains. I checked and otbr-agent has the commands in camelcase, however ha 2026.4.0 still sends them in pascalcase (this is captured with tcpdump):

PUT /node/dataset/pending HTTP/1.1
Host: 192.168.10.246:8081
User-Agent: HomeAssistant/2026.4.0 aiohttp/3.13.5 Python/3.14
Accept: */*
Accept-Encoding: gzip, deflate, br
Content-Length: 614
Content-Type: application/json

{"ActiveDataset":{"ActiveTimestamp":{"Authoritative":false,"Seconds":6,"Ticks":30314},"ChannelMask":134215680,"Channel":24,"ExtPanId":"redacted","MeshLocalPrefix":"fd19:a02e:46d8:e0f4::/64","NetworkKey":"redacted","NetworkName":"OpenThread-788f","PanId":redacted,"PSKc":"redacted","SecurityPolicy":{"AutonomousEnrollment":false,"CommercialCommissioning":false,"ExternalCommissioning":true,"NativeCommissioning":true,"NetworkKeyProvisioning":false,"NonCcmRouters":false,"ObtainNetworkKey":true,"RotationTime":672,"Routers":true,"TobleLink":true}},"Delay":300000}

[olivluca]

decent programming languages are case insensitive for a reason 🤣

[olivluca]

Now I see the problem (I think): this commit makes python-otbr-api accept camelCase in the answers from the agent but it still emits PascalCase (see here).

[olivluca]

FWIW I took the otbr-agent from the other gateway (running 2.1.4) and I can change the channel from ha, but I think the fault lies with that python library (or with google for pushing backward incompatible changes).

[jnilo1]

Thanks for testing @olivluca . All those changes do not seem very well coordinated ... I am away from home for a few days with no access to the gateway so I do not know if l'll be able to work on that issue until back home. In the meantime the v2.1.4 version seems to be the safest solution

[jnilo1]

@olivluca Great detective work with the tcpdump capture!

I dug into the python-otbr-api source and can confirm your analysis:

• Commit 5e5197a (shipped in v2.9.0 / HA 2026.4) added _normalize_keys() to parse camelCase GET responses — but left as_json() untouched, so PUT requests still emit PascalCase.
• Upstream ot-br-posix uses cJSON_GetObjectItemCaseSensitive to parse incoming PUT payloads → PascalCase keys are silently ignored → "Failed to call OTBR API".

The bug is on the python-otbr-api side. I opened an issue: home-assistant-libs/python-otbr-api#238

v2.1.5 has been updated: the PascalCase otbr-agent is kept (same as v2.1.4), so it works with all HA versions. The other v2.1.5 changes (scp/dbclient, rootfs rebuild fix, version bump) are all included. Users can re-pull and re-flash:

git pull
./flash_install_rtl8196e.sh <gateway_ip>

Thanks again for the thorough testing!

[olivluca]

Ok, I didn't open an issue, I just added a comment to the pull request (though I'm not sure they look at those once it has been merged).