Arceus Legal disclosed a $17 million funding round on October 1, 2026. The artificial intelligence-driven law firm plans to expand beyond the commercial contract work it started with.
Arceus serves fast-growing companies by offering flat prices quoted before matters begin. Licensed attorneys approve all work with assistance from proprietary AI agents and software. If a standard contract review exceeds eight hours, the client pays nothing. The firm states that most reviews finish within three to five hours. Its website lists that specific service at $500.
Speed forms a central element of the company pitch for businesses dealing with stalled agreements. Traditional firms often require days or weeks to return reviews while billing hourly for communications. Customers using traditional AI redlining tools must still verify outputs independently. Arceus handles that verification step for its clients.
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Attorneys at Arceus operate using an in-house platform named CounselOS. The operating system stores client preferences, previous agreements, and negotiation histories. New matters begin using existing institutional knowledge about the business. Integrations with Salesforce, HubSpot, and Gmail pull context directly from client tools. The platform assigns matters to lawyers while providing live progress updates through Slack and email.
Current operations focus largely on commercial contracts such as master service agreements, nondisclosure agreements, and vendor deals. Certain clients now send employment and privacy matters to the firm. The long-term objective involves building a practice capable of handling all legal needs for a business. Arceus reported that its customer base quadrupled in September.
Traditional billing models face criticism
Founder and Chief Executive Mac Liu experienced missed deadlines and unexpected bills while using multiple traditional law firms. He stated that the billable-hour model failed to make sense because firms gain incentives to work slower. Greycroft LP led the new funding round. Craft Ventures Management, South Park Commons Management, and other investors also participated.
Mark Terbeek, a partner at Greycroft, noted that most legal artificial intelligence companies sell software to existing law firms. He views Arceus as pursuing a larger opportunity by reconstructing the law firm structure itself.
The capital will support hiring efforts at the headquarters in San Francisco. Arceus is actively recruiting attorneys, engineers, and artificial intelligence researchers as the firm expands into new legal domains.
