Elon Musk took legal action on Monday against Apple and OpenAI, accusing the tech giants of anticompetitive behavior over their partnership to integrate ChatGPT into iPhone software. Filed on behalf of Musk’s companies X and xAI, the lawsuit claims that Apple and OpenAI have formed an exclusive deal that grants ChatGPT unfair access to Apple’s users and services, and harms rivals like Grok. The move follows weeks of Musk’s complaints about Apple’s promotion of ChatGPT, and comes as he tries to grow xAI’s model into a central feature of a proposed “everything app” on Twitter.

Filed in California federal court, the lawsuit goes well beyond a protest over App Store rankings or Apple’s in-store marketing. It accuses Apple of working in secret with OpenAI to create an exclusive partnership that not only grants ChatGPT access to iPhone features like Siri and writing tools, but that blocks other developers from accessing those same features. In the complaint, X claims this arrangement amounts to a monopolistic deal that will harm competition and put a chokehold on XAI’s progress on Grok, making it impossible for Musk to complete his announced vision of merging everything from social media and news to payments and messages into one mega app on Twitter.

Apple reportedly signed a deal to bake ChatGPT into iPhone and Mac systems late last year, which the company announced in March, following a series of integrations over the past year. At the time, Apple claimed the move would open up its systems to more third-party AI apps, not fewer. But Musk’s suit claims it is the opposite, and will instead let OpenAI corner the market by making it hard or impossible for other chatbot models to access the data they need to train and scale. That, X argues, gives OpenAI an unfair lead and risks permanently locking in its advantages.

OpenAI is believed to already dominate the market for text-based AI chatbots, with an estimated 80 percent share and rising, according to a recent filing by X with the Federal Trade Commission, cited in the suit. But Musk’s filing takes aim at what could happen next, now that Apple has given OpenAI an exclusive deal to be the only chatbot deeply integrated into iOS, while others like Grok have been kept on the margins. Apple has not allowed Grok to be preinstalled, its updates have been held in App Store queues, its content has been restricted by Apple’s App Tracking Transparency (ATT) framework, and rankings for Grok have been “manipulated,” the suit claims.

X says Siri alone could produce up to 55 percent of all chatbot prompts by 2026 if no other chatbot is integrated. Apple also handles 1.5 billion Siri requests per day, which “significantly outpaces total volume of prompts provided to all generative AI chatbots in 2024,” the suit states. With that kind of reach, Apple has effectively given OpenAI a $2 trillion marketing channel to reach its users. That dominance, X argues, violates antitrust and unfair competition laws and will have a “chilling effect” on future investments in rival models like Grok.

Musk’s lawsuit takes aim at OpenAI’s position as the top choice for AI chatbots, arguing it already faces few effective competitors and that its dominance is set to grow through Apple’s exclusive integration. Apple rejected attempts by xAI to integrate Grok on the iPhone and make it eligible to be preinstalled or promoted by Apple on iPhone and Mac, the suit states, despite accepting and implementing requests from Microsoft Bing. The complaint also criticizes Apple’s failure to feature Grok in the App Store and Apple Search after the debut of a new “Imagine” feature for Grok last month.

The lawsuit’s big-picture concerns mirror a broader backlash from regulators and rivals that Apple’s search deals have cemented Google’s dominance for over a decade. Musk’s complaint also takes aim at the secretive nature of the deal, with some public signals coming months after the fact from Apple announcements and engineers on Twitter. It also suggests Apple and OpenAI were aware of the anticompetitive issues with their deal, and still worked to keep it exclusive and private, so Musk’s company would be blocked from taking advantage of it.

Musk is seeking billions in damages and a permanent injunction that would block Apple from continuing its deal with OpenAI, which he calls a “massive antitrust violation.” An OpenAI spokesperson told Ars Technica that X’s claims were “meritless” and that Musk’s lawsuit “continues his ongoing pattern of harassment against Apple.” An Apple spokesperson declined to comment.