New York CNN  —  OpenAI in a court filing Monday said it was doing just fine without Elon Musk after he left the company in 2018 — and now Musk wants to claim all OpenAI‘s enormous success over the past six years for himself. OpenAI came out swinging in a new legal filing responding to the lawsuit Musk filed against it last month, calling the billionaire’s “incoherent” claims “frivolous,” “extraordinary” and “a fiction.” Musk, who co-founded OpenAI in 2015, has accused the company of breaching its founding agreement and diverging from its original, nonprofit mission by reserving some of its most advanced artificial intelligence technology for private customers. OpenAI last week pushed back on Musk’s claims in a blog post suggesting, essentially, that Musk is jealous that he is no longer involved with the company as it has become a leader in the AI arms race. The blog post included emails that Musk had previously sent to other OpenAI cofounders, including one from 2018 in which Musk told company executives that OpenAI should sell itself to Tesla to remain competitive. The company refused, and Musk left OpenAI later that year. Elon Musk Gonzalo Fuentes/Reuters Related article OpenAI publishes Elon Musk’s emails. ‘We’re sad that it’s come to this’ OpenAI’s court filing goes even further, accusing Musk of conjuring the supposed founding agreement to form the basis of a lawsuit designed to “advance his own commercial interests.” It claims that OpenAI did not have a founding agreement or any other agreement with Musk related to his funding of the company. “Were this case to proceed to discovery, the evidence would show that Musk supported a for-profit structure for OpenAI, to be controlled by Musk himself, and dropped the project when his wishes were not followed. Seeing the remarkable technological advances OpenAI has achieved, Musk now wants that success for himself,” the filing states. The filing asks a judge to designate the case as “complex,” which would, among other things, create some guardrails for the discovery process. OpenAI also said it believes that “early and swift dismissal” of Musk’s suit is warranted. OpenAI is concerned that Musk could use the discovery process to “seek access to OpenAI’s proprietary records and technology,” according to the filing. Musk is now running his own artificial intelligence company, XAI, which seeks to compete with OpenAI. OpenAI argues that Musk’s demand for relief — which includes a request to order OpenAI to make all of its technology and research available to the public — is “extraordinary” and would “benefit Musk, whose own for-profit AI concern has not met with success in the marketplace.” Lawyers for Musk did not immediately respond to a request for comment.