Bloomberg reports that Harvey, the legal AI company valued at roughly $15.6 billion, has moved its flagship off closed frontier models. The driver is arithmetic: gross margins collapsed from about 50% to minus 50% by June as customer token usage jumped twentyfold under OpenAI and Anthropic's usage-based enterprise pricing.

In August Harvey launched Tenet, its first in-house model, post-trained on Moonshot's open-weight Kimi K3 (a 2.8-trillion-parameter base released in July) in work the company did with Fireworks AI. Margins turned positive again after the migration. Former AI czar David Sacks publicly backed the move, saying Harvey built 'world-class specialized models' at a fraction of frontier-model cost.

Bloomberg names Abridge, Decagon and Ramp as pursuing similar open-weight pivots, backed by Sequoia and General Catalyst — the first serious wave of enterprise AI companies leaving closed-model dependence, driven by unit economics rather than capability.