Google exited China in 2010, but is now making another pitch to re-enter by promoting its TensorFlow software for building artificial intelligence solutions. Sources say that parent company Alphabet has added staff to look for potential AI investments among Chinese companies. The online Chinese market is the biggest in the world, but Google faces challenges there, not just with homegrown rivals such as Baidu, but the fact that China’s firewall keeps domestic developers from accessing Google’s cloud computing services.

Bloomberg reports Google chief executive Sundar Pichai declared that he was “committed to engaging more in China,” although he said he didn’t “know what the answers are.” Since Google left China over government censorship, it has “explored several paths for re-entry, including activating its mobile app store there, with little success,” although China is “the biggest market for smartphones running Google’s Android software, but without Google services.”

Baidu is also in direct competition “in the race to create the most popular foundational tools for inventions like voice-controlled speakers and self-driving cars.”

Google is planning more of a stealth move, by “getting developers in the country trained and hooked on its AI building blocks.” U.S.-based Google engineers have presented in-depth briefings at three developer events in Beijing and Shanghai in the last month, two of which, according to sources, were “invite-only, with attendees asked not to record, photograph or even blog about the sessions.”

Google, which began offering TensorFlow for free in 2015, is a “cornerstone” of the company’s “effort to re-orient its web services from a world where people type on screens to one where they talk to an array of devices.” The software has been downloaded more than 7.9 million times thus far, and China is now “one of the fastest growing TensorFlow developer communities in Asia, despite the fact that Google’s cloud services are unavailable there.”

Just as Pichai wants to make Google “AI First,” so the Chinese government “has made AI a national priority,” using machine learning systems for banking, drones and facial recognition. Baidu now offers its own AI toolkit, dubbed PaddlePaddle, and its spread “among developers has outpaced Google’s this year,” says one source.

According to AI expert Jiebo Liu, who studies China at the University of Rochester, it’s about loyalty. “They might use TensorFlow for prototyping,” he said. “But if they want to put something in product, they use their own.”