Tyler Lizenby/CNET

Editors' note, May 16, 2018: Google announced an updated plan for the Works with Nest migration that addresses a lot of the concerns of this article. Analysis of the update is below, followed by the original piece.

Google and Nest are merging into a single brand aptly called Google Nest. Along with the change, Nest customers will be encouraged to shift their Nest accounts into Google accounts, and Google is shutting down further development for the popular Works with Nest program that lets Nest products interact with other smart home devices from third parties.

Specialized triggers that could cause your smart lights to flash when your Nest Protect smells smoke looked to be in danger at Google I/O when Google announced that it was shutting down Works with Nest completely. Even the popular integration between Nest products and Amazon's assistant Alexa seemed to be threatened by the change. See the article below for all of those concerns, but as of Thursday morning, Google has now changed its plan for the merge to make sure Nest customers don't see an interruption in their smart home setups.

The most important change is that if you keep your Nest account, any recipes or automations you have set up with third-party gadgets will keep working after Aug. 31; you just won't be able to add new ones.

Closing Works with Nest in particular threatened the smart home setups of lots of Nest customers. Google encouraged developers to join Works with Google Assistant as a replacement, but Google Assistant devices like the Google Home smart speaker only control third-party gadgets, not the other way around. If your smart home setup automatically caused your Nest Cam to start recording when an alarm sounded, or your Nest Thermostat to go into away mode when you left, it looked like those integrations would stop working.

Google is still focusing new features on Google smart home accounts moving forward -- Nest accounts will be moved to a maintenance mode and receive only security updates, but at the very least, the change now won't sever the smart home connections you've come to rely on.

Otherwise, in the blog post announcing the shift, Google revealed upcoming changes to Google Assistant and routines that will bring over a lot of the functionality that was previously going to be cut. Google is working with Amazon so that Alexa and Nest can keep working together. Google will be updating their grouped commands called Routines so that you can automatically shift your thermostat into home or away mode as you come and go.

Google is also promising to add more custom integrations with third parties, but it will put these partners through a security audit and you'll be able to choose which devices and which data you want to share with them, as opposed to an all-or-nothing approach.

If you currently have a Nest account and an advanced smart home setup, you should probably not merge it into a Google account until these new features are finalized. When you merge, any current Works with Nest connections you have set up will still be cut and you can't go back. If Google's update with your other smart home gadgets isn't ready, you won't be able to set up replacement routines either.

However, Thursday's blog post essentially removes the ticking clock on Nest-centered smart homes. Until Google has the changes ready, you can just keep your Nest account and your smart home will continue to work as expected. Google and its third parties had previously made clear that updates were in the works, but now the hard deadline of August 31 shouldn't be an issue.

Other smart home developers seem reassured by the update. "We are happy to see that Google seems to understand how detrimental it would be for existing Nest users to have their integrations stop working," said Chris Carney, CEO and co-founder of Abode, maker of one of our favorite smart home security systems. "Abode will continue to work with Google as [its] plans for Works With Google Assistant evolve and we hope that we're able to collectively offer the same level of functionality and compatibility that made Nest such a successful brand and important partner over the last several years."

"It looks like Google is trying to smooth the path for developers and consumers to move from the Nest platform to Google's," said Jason Johnson, CEO of August, maker of the August smart lock. "We welcome this approach and look forward to supporting one integrated platform rather than two partially integrated platforms."

"Our understanding is that existing [Works with Nest] integrations will be transitioned before the platform is disabled. We'll continue to have conversations with the team at Google to help with the transition," said Chris Klein, CEO of Rachio, maker of the popular Rachio smart sprinkler.

A Lifx representative reinforced the need for patience: "In the short term people that migrate from a Nest Account to a Google account will lose those [Nest specific] features until the time that [Works with Google Assistant] chooses to support them later this year."

The original article from May 14:

The Amazon Echo and the Nest Learning Thermostat are two of the biggest hit products of the smart home. They've also worked together for years. You can ask Alexa, the voice assistant built into the Echo smart speaker, to change the temperature on your Nest thermostat. After Google I/O, this important smart home connection looks in danger of being cut.

Google and Nest have been technically part of the same team since last year, but last week at Google I/O, Nest and the Google smart home team joined into a single brand called Google Nest. In addition to a new product -- the Nest Hub Max -- and a few price cuts, the joined brand also means Google will encourage current Nest customers to merge their previously siloed Nest accounts with Google.

You'll still be able to keep your Nest account, but it will be relegated to a "maintenance mode" and it will only receive security updates. New features will all be designated for Google accounts. If you already center your home around Google's smart home products -- such as the Google Home smart speaker -- this shift isn't likely to have a big effect on you. In fact, more functionality is likely to be rolled into the Google Home app to help encourage customers to move away from the separate Nest app.

If you primarily use Nest products and automated recipes involving third-party gadgets, your current smart home set up could turn dumb as soon as Aug. 31, 2019. On that date, Google is shutting down the Works with Nest program, which allowed third-party developers, including Amazon, to control Nest gadgets.

Developers can join the Works with Google Assistant program instead, and many of the major brands that work with Nest already work with Google, but the two programs have a few fundamental differences that could sever the connections you have set up at home.

One-way commands

Works with Nest allowed third-party gadgets to both give and receive info from Nest products like the Nest Learning Thermostat. Works with Google Assistant debuted to replace Works with Nest, but Google Assistant has thus far only given the commands to third-party products, not the other way around.

Abode is a good example of a smart home company that currently works with both systems. Abode makes one of our favorite DIY security systems. Different Abode kits include a variety of sensors, sirens, cameras, and even gadgets like switches, lights and dimmers.

Chris Monroe/CNET

If you integrate Abode with Google Assistant, you can control Abode's lights, switches and dimmers with a voice command to a nearby Google Home (or any other gadget with Google Assistant built-in). If you integrate Abode with Nest, you can tell your Nest Cam to start recording if an Abode motion sensor causes an alarm. You can turn the Nest Thermostat to away mode automatically when you arm your Abode system. The integrations are more robust because Nest can both give and receive information from Abode.

"We've always believed the smart home experience is made better for customers through interoperability and companies working together to give consumers choice," said Chris Carney, CEO and co-founder of Abode. "While Google's choice to shut down the 'Works with Nest' program is contrary to our belief and against the direction we think the smart home needs to move, it is consumers who will be impacted the most."

Right now, Nest products can control Abode products, and Abode products can control Nest products. With Google Assistant, Nest products could be forced onto a one way street.

If Works with Google Assistant doesn't allow input from third party devices by Aug. 31, the effect on the smart home will be widespread. For Abode that would mean you would no longer be able to trigger an action from one device based on the behavior of another one. In other words, that Nest Thermostat away mode automation when you arm your Abode system would no longer work.

Online rule maker IFTTT offers a variety of recipes that let you control your Nest devices with other gadgets. IFTTT already works with Google Assistant, but all of the recipes directly involving Nest will stop working when Works with Nest shuts down, and recreating them with Google Assistant will be tough. Google Assistant only offers recipe triggers, not actions that respond to third party triggers.

This disconnect will be most widely felt by Nest device owners that use Alexa as their voice assistant. A Google representative offered some reassurance on this front, "We're working with Amazon to migrate the Nest skill on Amazon Alexa to ensure a smooth transition for Nest customers prior to winding down the Works With Nest program"

If Google adds the necessary code to Works with Google Assistant that will let Amazon control Nest devices, that code could theoretically allow other affected manufacturers to keep their current functionality as well.

"Abode will do everything we can to make this as painless as possible for our customers and have already begun working on enhancing our existing Google Assistant integration and will be adding additional features as they become available to us," said Carney.

An Amazon representative put the onus for the change on Google, "I would defer you to the device manufacturer for questions about their products."

Triggering change

Works with Nest and the Nest app are capable of a few other features that Google will need to add by September if they don't want customers to feel any interruption in service. The Nest app allows you to assign levels of access to members of your home, the Google Home app doesn't. If you add someone to your home through Google, they have access to all of your devices and can even remove you from the home.

To be clear, the Nest app isn't shutting down, but given the way Google is pushing people towards Google accounts and away from Nest accounts, the Google Home app will be the new center of the combined brand.

You still can't set up Nest gadgets using the Google Home app. Nest also uses smart home triggers with a lot of third-party gadgets. With Philips Hue, Lifx, Lutron and other smart lighting companies, you can program your lights to flash red if your Nest Protect senses smoke. You can have them turn on and off at various intervals when your Nest Thermostat knows you're away in order to fool would be intruders.

In these cases, the Nest product is the one sending the info to the third-party gadget and controlling them accordingly. Google might be able to add similar functionality to Works with Google Assistant even if the company doesn't want to receive commands from third-party gadgets, but Google doesn't have similar triggers yet.

You can create grouped commands called routines for Google Assistant. Say "good morning" to your Google Home, and it can turn on the lights, set the temperature of your thermostat and even play your favorite podcast. You can customize a routine to trigger on any command you'd like and can even schedule routines to start at a certain time so you don't need to use a voice command.

Google has also promised that you'll be able to trigger morning routines from your phone's alarm, and the upcoming Nest Hub Max smart display will be able to automatically relay personalized information when it recognizes that you've walked into the room. These are all effectively triggers, which is what Nest uses to flash your lights red, but as of now, Google doesn't let you fully customize triggers.

Now playing: Watch this: The Google Nest Hub Max soups up the smart display

Routines are limited to voice commands, schedules, and potentially a few extras determined by Google. You can't train one smart gadget to respond to the input of another. When asked for comment, the involved smart home companies have generally said that they're working on it.

"We're working closely with Google to continue to deliver the best possible experience to our customers," said a representative from Philips Hue. "For now, we recommend they keep an eye on the Nest FAQ and Google's and our social channels for more updates as we approach Aug. 31, 2019."

A representative from Lifx said that they "are in regular contact with the team there to develop integrations as soon as we hear about any changes to the architecture."

Matt Swatsky, the Vice-President of Lutron's Residential Mid-Market Business, said, "We look forward to working with Google on their Works with Google Assistant program to determine the best way to take care of our joint customers and maximize the Lutron user experience."

Nest has similar triggers that can turn on smart sprinklers from Rachio when the Nest Protect smells smoke. "We're always evolving and upgrading our integrations, so this will be no different," said Chris Klein, the CEO of Rachio.

One of the reasons Google might not add these triggers is the company's renewed focus on privacy. Along with the new Google Nest brand, Google announced privacy initiatives to keep customers informed about what data their smart home was collecting and how it was being used. If your Nest Thermostat is going to trigger your Philips Hue lights, it needs to share data with Philips.

Lots can happen in the interim

Tyler Lizenby/CNET

Three and a half months is a long time in the tech world. A Google representative offered more reassurance over email: "The majority of our most popular Works With Nest partners are already up and running with the Works with the Google Assistant platform and we're actively collaborating with other partners on the transition. We're also working to improve Assistant Routines so people will be able to replicate the top integrations."

Even in the unlikely worst-case scenario, in which Google doesn't add any of Nest's existing functionality to Google Assistant before shutting down Works with Nest, lots of related smart home integrations will continue to function normally. You'll still be able to control your Nest gadgets with your Google Home. Any integrations you've built around Google Assistant will be unaffected.

Some major Works with Nest brands, like August, are minimizing the impact. August, the makers of the August Smart Lock, is part of the Works with Nest program. You can see the status of your Nest gadgets in the August app and set your thermostat to Home or Away when you lock or unlock your door.

The change should have "a very minimal impact for August customers," said Jason Johnson, CEO of August. "Our Google Assistant integration doesn't change and that is a far more popular integration."

Nevertheless, Amazon and Google are certainly capable of letting ongoing battles affect customers, and if Alexa stops being able to control Nest products, that could have a huge and negative impact on a lot of smart home customers.

Google Nest launched with a cool new product, price cuts, and a renewed focus on privacy. The joined brand makes sense given that the two teams were already ostensibly part of the same unit. Still, joining the brands and ending Works with Nest could make a lot of smart homes much dumber, and Google has a lot of work to do before Aug. 31 to make sure that doesn't happen.

Originally published May 14.