Features

MCP Integration: AI Tools and Lexnus

Lexnus exposes its policy engine and clause library as an MCP (Model Context Protocol) server. Your AI assistant in Word, any MCP-compatible AI interface, and any MCP-compatible agent can call Lexnus directly to evaluate clauses, retrieve approved language, and check compliance against your playbook in real time. General-purpose AI becomes safe for professional legal use not by restricting what it can do, but by giving it a governed policy layer to work against.

What MCP is and why it matters

Model Context Protocol (MCP) is an open standard for connecting AI tools to external systems. When a lawyer is working in Word with their AI assistant, the AI model can call Lexnus's MCP server to look up approved clauses, evaluate a specific provision, or run a compliance check, without the lawyer leaving their workflow or switching applications.

The result: AI drafting grounded in your organisation's approved language, not generated from scratch.

How it works

The architecture

The AI model operates as the AI layer. Lexnus operates as the policy layer. They are separate and complementary:

  • The AI model reads, interprets, drafts, and explains legal text.
  • Lexnus stores your approved clauses, enforces your rules, and determines whether any given clause or contract complies with your policy.

When the AI model is connected to Lexnus via MCP, it grounds its outputs in your organisation's standards. It asks Lexnus what your approved liability clause says. It checks whether the termination notice in a counterparty's draft meets your minimum. It retrieves the right jurisdiction-specific variant of a clause for the deal at hand. The AI model provides the language intelligence. Lexnus provides the policy authority.

Available tools

Lexnus's MCP server exposes the following tools to connected AI agents:

  • lexnus_evaluate_clause — Submit any clause text for evaluation against your active playbook. Returns: violation, gap, or pass, with the specific rule triggered and the approved alternative.
  • lexnus_search_clause_library — Search your organisation's clause library by category or keyword. Returns: published, approved clause variations matching the query.
  • lexnus_get_approved_clause — Given a clause category and deal context (Smart Field values), retrieve the best matching approved clause variation. This is how the AI model knows which liability cap to use for a $2M UK deal versus a $500K Swedish deal.
  • lexnus_get_playbook_rules — Retrieve all rules in the active playbook for a given contract type. Returns: rule text, conditions, and escalation requirements.
  • lexnus_analyse_document — Trigger a full document analysis asynchronously. Returns a job ID; retrieve results with lexnus_get_analysis_result.
  • lexnus_save_version (write) — Save the current document state as a new contract version in your Lexnus repository.
  • lexnus_submit_for_approval (write) — Submit a flagged violation for GC approval from within the AI tool.
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Authentication and audit

MCP connections authenticate via OAuth with explicit scope selection. Read tools and write tools require separate permission grants. Every MCP tool call is logged to Lexnus's audit trail: caller identity, account, workspace, timestamp, inputs, and outputs. Write operations log before-and-after state snapshots. No AI action on a Lexnus-governed contract goes untracked.

Key capabilities

  • Clause grounding — Instead of generating novel legal language, the AI model retrieves your organisation's approved clauses from the Lexnus library. AI drafting stays within your governed standards.
  • Real-time compliance checking — During drafting or review, the AI model can call Lexnus to check whether a specific clause or provision passes your playbook rules before it goes anywhere.
  • Full audit trail — Every MCP call is logged. The audit trail distinguishes human-initiated calls from agent-initiated calls (overnight triage, automated review pipelines).
  • Account and workspace scoping — MCP tools are strictly scoped. Cross-account data access is architecturally prevented.
  • Provider agnostic — The MCP integration is not exclusive to any single AI provider. Any MCP-compatible AI tool can connect to Lexnus. The policy layer works regardless of which AI you use.

Who uses this

Lawyers using AI tools in Word get their AI drafting assistant grounded in the organisation's approved language. When they ask the AI model to draft or fix a clause, the AI model calls Lexnus to retrieve the right approved version rather than generating something new.

Legal Ops teams building automated contract workflows can use Lexnus's MCP server as the policy enforcement step in any agentic pipeline. An agent that generates draft contracts calls Lexnus before the output reaches anyone.

General Counsel gain oversight of what AI tools are doing with their organisation's contracts. Every AI action that touches a Lexnus-governed contract is in the audit log.

Frequently asked questions

What is MCP and how does it work?

Model Context Protocol is an open standard for connecting AI tools to external systems. When you connect Lexnus to your AI model via MCP, the AI model can query your clause library, evaluate clauses, and run compliance checks as part of its responses, without you switching applications.

Does Lexnus work with any AI model?

Yes. The MCP standard is open and provider-agnostic. Any AI tool that supports MCP can connect to Lexnus's policy engine. Lexnus is designed to work with any AI layer, not exclusively with Anthropic's products.

Is Lexnus's MCP integration secure?

Yes. Connections authenticate via OAuth. Read and write access are separate scopes, and explicit user consent is required for write access. Every call is logged to an immutable audit trail. Cross-account data access is architecturally prevented and tested.

What is the difference between an AI model generating a clause and retrieving one from Lexnus?

When the AI model generates a clause from scratch, the output is new language that has never been reviewed by your organisation. When the AI model retrieves a clause from Lexnus, it returns language that has been reviewed, approved, and published by a qualified lawyer at your organisation. The first is fast but ungoverned. The second is fast and governed.

Does using Lexnus via MCP replace the Lexnus web application?

No. The MCP integration is a second access point to Lexnus's policy engine, one that works inside AI tools like your AI assistant in Word. The web application is where you build and manage playbooks, review clause submissions, and monitor compliance health. Both work together.

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