The threat came via Musk’s platform X, where he claimed: “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. xAI will take immediate legal action.”

In a follow-up, he added: “Why do you refuse to put either X or Grok in your ‘Must Have’ section when X is the #1 news app in the world and Grok is #5 among all apps? Are you playing politics?”

Job’s Mob replied with its usual PR sugar: “The App Store was designed to be fair and free of bias, thousands of apps through charts, algorithmic recommendations, and curated lists selected by experts using objective criteria.”

According to the spokesperson, the platform is there to support developers and provide “safe discovery” for users.

The flare-up comes as Job’s Mob gets increasingly cosy with OpenAI, whose ChatGPT now comes baked into iPhones, iPads and Macs. Musk previously called this integration a “security violation” and threatened to ban Apple kit from his companies.

The latest spat follows a brief moment of Muskian triumph, when he crowed that Grok had overtaken Google in the App Store and become the fifth top free app.

CNBC confirmed that ChatGPT remains top dog in the US App Store’s free section and is the only AI bot featured in Apple’s “Must-Have Apps” list. Job’s Mob plastered a banner promoting OpenAI’s latest GPT-5 release across its app section.

Musk’s legal sabre-rattling follows OpenAI’s recent launch of GPT-5, its flashiest AI model yet. That dropped not long after xAI unleashed Grok 4, clearly hoping for some limelight before being quietly shoved aside in Apple’s rankings.

xAI has yet to confirm whether Musk’s legal threat will amount to more than another rant on X.