Anthropic on Tuesday released its most aggressive push yet into the legal industry: 12 new practice-area plugins, more than 20 Model Context Protocol connectors linking Claude to the software law firms already use, and a cross-app integration with Microsoft 365 that embeds Claude across Word, Outlook, Excel, and PowerPoint.

The company disclosed that legal is now the top power-user job function on its Cowork platform. More than 20,000 legal professionals signed up for Anthropic's most recent legal webinar, the largest legal session it has ever held.

The Big Names Are Already In

The rollout came with a roster of marquee adopters. Freshfields, Quinn Emanuel Urquhart & Sullivan, Holland & Knight, and Crosby Legal all announced they are using Claude on live matters. Freshfields co-head Gerrit Beckhaus said the firm is co-developing "agentic workflows" with Anthropic that handle multi-step legal tasks end to end.

Quinn Emanuel partner Christopher D. Kercher said he personally built the firm's litigation platform on Claude "with virtually no coding background" because he needed it for an active trial. "The breakthrough was treating Claude like a member of the case team," he said. "The work product is far beyond what I would've done on my own."

The new plugins cover M&A due diligence, employment handbook drafting, privacy compliance, corporate governance, AI regulatory work, and other practice areas. The MCP connectors integrate Claude with Docusign, Box, iManage, Thomson Reuters' Westlaw, and CourtListener's archive of real court opinions.

The Hallucination Problem Has Not Gone Away

The expansion arrives against an uncomfortable backdrop. Dozens of lawyers have been caught submitting AI-generated filings riddled with fake case citations. Sullivan & Cromwell, one of the most prestigious law firms in the world, was found just weeks ago to have included a hallucination in a bankruptcy court filing. California issued the first state fine against an attorney who used ChatGPT to draft an appeal filled with fabricated quotes. Federal judges have also been caught using AI to draft rulings.

Anthropic's answer is what it calls "grounding." The new connector architecture forces Claude to draw only from live, verified sources: Westlaw case law, CourtListener opinions, iManage document repositories. The theory is that an AI reading a real document behaves differently from one synthesizing text from training data.

Claude Opus 4.7 scored 90.9% on Harvey's BigLaw Bench, the legal industry's most closely watched AI benchmark. Jay Madheswaran, CEO of legal AI company Eve, said his company evaluates every model against "24+ legal-specific scorers" and that Claude "wins our internal bake-offs every time on the metrics that matter for legal work, particularly grounding and citation faithfulness."

A $11 Billion Market, Getting More Crowded

Anthropic is entering a market that is already fiercely competitive. Harvey, the AI legal startup, raised $200 million in March at an $11 billion valuation. Legora, its chief rival, raised a $600 million Series D last month and launched a campaign with Jude Law as spokesperson. Both companies are built on Claude's underlying models, which means Anthropic is now simultaneously partnering with and competing against its own customers.

Thomson Reuters sits in a similarly complicated position: it is both a Claude data connector (giving Claude access to Westlaw primary law) and a seller of its own competing AI legal products.

Anthropic is also framing the push as an access-to-justice play. Roughly 80% of civil litigants appear in court without a lawyer, according to the company. Through partnerships with the Free Law Project, Courtroom5, and other legal aid organizations, it is making connectors available to Claude users at no additional cost. "Most people don't know they have legal rights until it's too late to use them," said Courtroom5 CEO Sonja Ebron.

The legal industry has clearly made its bet. Whether the guardrails are good enough will be settled, eventually, in court.

Sources: Fortune, TechCrunch, Reuters