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How the Anthropic Legal Plugin Works (and How to Use It Without Claude Code)

How the Anthropic Legal Plugin Works (and How to Use It Without Claude Code)
author

By Steven Obiajulu

February 2, 2026

5 min read
blog Legal Tech AI Anthropic Contract Review NDA Legal Plugin

On January 30, 2026, Anthropic released Cowork plugins — a set of open-source, structured skills for knowledge work. Among them: an official legal plugin.

This isn't a chatbot. These are structured workflows that produce consistent, auditable output. The code is public under the Apache-2.0 license.

Here's what the legal plugin actually does, what the skills check, and how to use them without running a CLI.

What Anthropic Released

The legal plugin is part of Anthropic's broader Cowork feature. It includes specific "skills" — structured workflows, not free-form prompts:

  • NDA Triage Skill: A checklist-based workflow for reviewing non-disclosure agreements
  • Legal Risk Classification Skill: A severity-by-likelihood framework for contract risk factors

The repository is at github.com/anthropics/knowledge-work-plugins. Coverage from Artificial Lawyer and TechCrunch provides additional context.

What the NDA Triage Skill Checks

The NDA triage skill walks through a structured checklist. Each item receives a status: Standard, Needs Attention, or Missing.

Category What It Checks
Obligations Mutual vs. one-way confidentiality
Definitions Scope of "confidential information"
Carveouts Public info, prior knowledge, independent development
Term Duration of agreement and survival period
Termination Standard vs. non-standard termination rights
Return/Destruction Obligations at agreement end

The output is structured — same headings, same format, every time. This makes it useful for comparing across deals and for teams that need consistent first-pass review.

What the Legal Risk Classification Does

The risk classification skill uses a severity-by-likelihood matrix:

  • Severity: The potential impact if the risk is realized
  • Likelihood: The probability of the risk occurring

It doesn't tell you what to do. It surfaces factors for lawyer review in a consistent format. Think of it as structured triage, not legal advice.

How to Use It via Email

The Anthropic version runs in Claude Code (a CLI tool) or Claude Cowork. Both require some technical setup.

We built an email interface for the same open-source playbooks. Forward a contract to junior@usejunior.com and receive structured analysis in your inbox:

  1. Forward any contract to junior@usejunior.com
  2. Receive a structured triage checklist
  3. Review the standard vs. non-standard flags with your team

No portal login. No software installation. No dashboard to learn.

For more details on the email workflow, see our landing page.

Our Contribution: PR #6

We submitted Pull Request #6 to the Anthropic repository. The contribution addresses unauthorized practice of law (UPL) risks by refining terminology:

  • Changed "assess risk" to "classify risk factors"
  • Ensured output stays focused on data classification rather than legal advice
  • Added whistleblower carveout alignment

These are subtle but important distinctions for legal defensibility. The PR is public — you can read the changes yourself and contribute your own improvements to the open-source framework.

Try It

Forward a contract to junior@usejunior.com to see the structured output for yourself. Or request a walkthrough to see it in action.


Disclaimer: UseJunior is a productivity tool for legal professionals. We do not provide legal advice. All AI-generated outputs must be reviewed by a licensed attorney. The author practiced law for six years at Ropes & Gray LLP prior to co-founding UseJunior. This implementation is based on the open-source legal plugin content from Anthropic's knowledge-work-plugins repository (Apache-2.0 License).


References

  1. "Anthropic Cowork Plugins Repository," GitHub, accessed February 2, 2026, https://github.com/anthropics/knowledge-work-plugins
  2. "Anthropic Moves Into Legal Tech," Artificial Lawyer, February 2, 2026, https://www.artificiallawyer.com/2026/02/02/anthropic-moves-into-legal-tech/
  3. "Anthropic Brings Agentic Plugins to Cowork," TechCrunch, January 30, 2026, https://techcrunch.com/2026/01/30/anthropic-brings-agentic-plugins-to-cowork/
  4. "UseJunior PR #6: UPL Safety Tweaks," GitHub, https://github.com/anthropics/knowledge-work-plugins/pull/6

About Steven Obiajulu

Steven Obiajulu
Steven Obiajulu

Steven Obiajulu is a former Ropes & Gray attorney with deep expertise in law and technology. Harvard Law '18 and MIT '13 graduate combining technical engineering background with legal practice to build accessible AI solutions for transactional lawyers.

New York, NY UseJunior Harvard Law '18, MIT '13 • Former Ropes & Gray
Last updated: February 2, 2026

UseJunior is a tool for law firms and licensed attorneys. We do not provide legal advice.