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Claude Legal Plugin Explained: Features, Cost, and Setup

Last updated: Apr 17, 2026

Written by

Niko Pajkovic

Claude Legal Plugin Explained: Features, Cost, and Setup

Anthropic has released the Claude Cowork legal plugin as part of a broader set of open-source tools for knowledge workers. The plugin analyzes legal documents for lawyers at no extra cost beyond a Claude subscription.

This article breaks down what the plugin does, its cost, how to set it up, and how its features compare to legal-specific AI tools such as Spellbook.

Key Takeaways

The Claude Cowork legal plugin is a free, early-access tool for paid plan users. It runs locally on macOS and Windows through the Claude Desktop app.
Anthropic advises against using the plugin for high-stakes or regulated legal work. All outputs require lawyer review before use.
Spellbook offers a robust alternative plugin that operates natively in Microsoft Word and is powered by a purpose-built legal AI model.

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What is the Claude Cowork Legal Plugin?

Anthropic released 11 open-source knowledge work plugins on January 30, 2026, and the legal plugin was among them. The plugin runs in Claude's Cowork desktop application, locally on your machine. You use it to analyze contracts, triage NDAs, and check vendor agreements, without writing any prompts yourself.

Unlike using Claude without the legal plugin, you would paste in contract text and write your own prompts. The legal plugin lets you query contracts via pre-built commands for common legal workflows. It relies on a local configuration file where a company defines its specific risk tolerances and standard clauses.

The plugin is available to those on a paid Claude plan.

The Claude Legal Plugin’s Capabilities and Limitations

The legal plugin connects Claude's reasoning capabilities to legal-specific data sources, but it does not contain an AI model trained on legal corpora. It integrates Claude's AI capabilities into existing legal workflows via pre-built commands, rather than requiring teams to prompt from scratch.

However, three constraints matter. First, this is an early-access tool. Anthropic advises against using it for high-stakes or regulated legal work, as it's currently an early-access tool, not yet a finished product.

Second, the output quality depends on how well you've configured your company's legal playbook file.

Third, the plugin operates outside Microsoft Word, which means it cannot edit documents directly. It does not embed in Microsoft Word or any other document editor. You must upload or paste documents into the Cowork interface.

Claude Legal Plugin Commands

The plugin comes with five pre-built tasks for common legal workflows. Here's what each one does:

Review Contracts

The /review-contract command runs a clause-by-clause scan of any uploaded contract. It extracts key clauses, obligations, and deadlines and assigns each clause a GREEN, YELLOW, or RED status.

The output includes redlined edit suggestions. The AI also flags high-risk or non-standard language for attorney review. This makes it useful for paralegals and junior associates handling first-level document analysis before escalating to senior counsel.

Sort NDAs

High-volume legal teams process dozens of NDAs per week. The /triage-nda command sorts each NDA into one of three tiers (standard approval, counsel review, or full review) and cuts time spent on routine document review tasks.

Check Vendor Contracts

The /vendor-check command is a fast compliance scan that checks vendor contracts against your company's playbook standards and flags deviations. It helps in-house teams enforce their legal standards consistently across every vendor engagement.

Generate Briefs

The /brief command allows you to generate daily briefs, topic research, or incident responses. It can also help non-lawyers understand their contractual obligations by requesting plain-English summaries.

Get Answers to Inquiries

The /respond command provides you with answers to data subject access requests, legal holds, and standard inquiries. Never send out a generated response without attorney review.

Claude Legal Plugin Requirements and Cost

The Claude legal plugin runs on both macOS and Windows through the Claude Desktop app. To use the Claude legal plugin, you need a paid subscription: Pro is at $20 per month, Max starts at $100 per month, or a Team or Enterprise plan.

You must enable the Claude Cowork desktop app in your account. The plugin itself is free. Team and Enterprise plan owners can distribute plugins across their organization through plugin marketplaces.

How to Install the Claude Cowork Legal Plugin

Visit claude.com/plugins/legal, sign in with your paid Claude account, and click "Add to Cowork." The plugin will appear in your Cowork sidebar once installed.

How Spellbook Compares to the Claude Legal Plugin

Claude is one of the LLMs that power Spellbook. However, Spellbook takes a fundamentally different approach to using AI to review contracts. Spellbook operates natively inside Microsoft Word documents, enabling you to redline, review, and draft contracts without switching applications.

Here’s when to use Claude and when to use Spellbook:

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Use the Claude Legal Plugin when…	Use Spellbook when…
You're a solo practitioner or a small in-house team testing AI workflows on a budget	You manage contract review across your legal team
You handle routine internal documents that don't involve regulated workloads	Your firm needs a tool that's ready for real client work, not an experimental preview
You need only basic NDA triage or vendor checks	You need consistent built-in playbook enforcement
You want a low-commitment way to experiment with AI-assisted contract review	Your team works in Microsoft Word and needs AI that works there, too

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Spellbook is similar to Claude, but is purpose-built for legal work. Request a free demo to see how Spellbook can accelerate and improve your contract review workflow.

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Frequently Asked Questions

Is the Claude Legal Plugin Free?

Yes, the Claude legal plugin is free for all Cowork users on paid plans (Pro, Max, Team, Enterprise).

Is the Claude Legal Plugin Available on Windows?

Yes, the Claude legal plugin is available on Windows and macOS. Download the latest Claude Desktop app from claude.com/download to get started.

Can I Use the Claude Cowork Legal Plugin for Client Work?

Anthropic labels the plugin a research preview and advises against its use on regulated workloads. The company states that "all outputs should be reviewed by licensed attorneys." Proceed with caution and consult your firm's AI policy.

What is the Difference Between the Claude Legal Plugin and Spellbook?

The Claude legal plugin is a free, early-access tool that runs on a general-purpose AI model. Spellbook is a legal-specific AI plugin that runs natively in Microsoft Word.

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