A nine-member jury was seated on Monday in the San Francisco courtroom of Judge Yvonne Gonzalez Rogers, formally beginning the trial in which Elon Musk accuses OpenAI and its chief executive Sam Altman of breaching the charitable trust under which the company was originally founded.

The case centres on Musk's claim that OpenAI abandoned its founding mission as a non-profit dedicated to the benefit of humanity when it restructured into a capped-profit entity and deepened its commercial relationship with Microsoft. Musk, an early backer and co-founder who departed the board in 2018, filed the lawsuit in 2024. The trial represents the most significant legal challenge yet to OpenAI's corporate transformation and its trajectory toward a full for-profit structure.

Jurors were drawn from a range of professional backgrounds and, according to reporting on the selection process, hold mixed personal experiences with AI products. That detail may prove consequential: both sides are expected to argue about the nature of OpenAI's obligations and whether its commercial pivot served or undermined the public interest. Judge Gonzalez Rogers, who presided over the Epic v Apple antitrust case, is overseeing proceedings.

What this signals

The trial arrives at a moment when OpenAI is simultaneously pursuing a restructuring that would convert its non-profit parent into a public benefit corporation, a move that has itself drawn scrutiny from the attorneys general of California and Delaware. A verdict against OpenAI could complicate that process, though legal observers have noted that breach-of-charitable-trust claims are difficult to prove and that Musk faces a high evidentiary bar.

For the broader AI industry, the proceedings put a public spotlight on the governance tensions that arise when organisations founded with explicit safety or public-benefit mandates attract large-scale commercial investment. xAI, the AI company Musk founded in 2023 after his departure from OpenAI's board, is a direct competitor to OpenAI in the frontier model market, a fact OpenAI's legal team is expected to raise in arguing that the lawsuit is motivated by competitive interest rather than principled concern.

The trial is expected to run several weeks. Closing arguments and a verdict are not anticipated before late May at the earliest.