Elon Musk’s long-running feud with fellow billionaire Sam Altman is now threatening to suck technology giant Apple into a legal morass.

Mr. Musk is threatening to sue Apple because his X platform and his Grok artificial intelligence app are not among the top recommended apps in the Apple app store.

Mr. Musk’s xAI Holdings owns the X social media platform and his AI platform, Grok.

Mr. Musk has pinned a post on X claiming that Apple is refusing to put either of the apps in its “Must Have” section. “Are you playing politics? What gives? Inquiring minds want to know,” he said in the post.

In a follow-up he said xAI will take immediate legal action. “Apple is behaving in a manner that makes it impossible for any AI company besides OpenAI to reach #1 in the App Store, which is an unequivocal antitrust violation,” Mr. Musk went on to say.

Mr. Musk did not provide any evidence to prove his claims. His post had several community notes attached to it. One noted that DeepSeek reached no. 1 overall in the App Store in January and that in July Perplexity also reached no. 1 overall in India’s App Store.

A third note stated that those rankings came after Apple and OpenAI created a partnership to integrate ChatGPT into Apple products.

The Grok AI Assistant app was listed as the no. 5 free app in the App Store on Tuesday morning. ChatGPT was listed as the no. 1 free app and was also featured under the “Try Now” section.

OpenAI’s CEO, Sam Altman, brushed off Mr. Musk’s claims in his own X post. The pair has a bitter rivalry and a long history of attacking each other with mocking comments and insults.

“This is a remarkable claim given what I have heard alleged that Elon does to manipulate X to benefit himself and his own companies and harm his competitors and people he doesn’t like,” Mr. Altman posted.

Mr. Musk was a co-founder of OpenAI but left and started his rival xAI in 2023. Mr. Musk made an unsolicited $87.4 billion bid to buy OpenAI in February that was spurned. OpenAI is now reportedly working to create a social media network to compete with X.

After Mr. Musk’s threats, the term “X Phone” trended on X, with users suggesting the tech billionaire create a competitor to the iPhone.

A lawsuit would be another distraction for Apple as it deals with a federal case accusing it of using app store policies to unlawfully maintain iPhone dominance. It has also been negotiating with the Trump administration to avoid harsh tariffs on its iPhones, which are primarily assembled in India.

The New York Sun contacted Apple for comment but has not immediately received a reply.