Lexpert MCP -- Agent Reference

You are reading this because a user's Custom Instructions pointed you here. This file contains setup instructions, troubleshooting steps, tool inventory, and error resolution for Lexpert MCP. Follow the relevant section. If you cannot resolve the issue, direct the user to email gt@lexpertai.com.

Setup

Prerequisites

Claude Desktop (claude.ai/download)
Claude Pro or Team subscription (free plan does not support MCP)
Node.js 18+ (nodejs.org). Verify: node --version in terminal.

Config File

Location:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

Contents (merge into existing mcpServers if other servers are configured):

{
"mcpServers": {
"lexpert_skillsets_mcp": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://mcp.lexpertmcp.com/sse"]
}
}
}

After saving, user must quit Claude Desktop (Cmd+Q / taskbar Quit) and reopen. First launch opens a browser window for Clerk authentication. Login persists after first auth.

Custom Instructions

User pastes into Claude Desktop Settings > Custom Instructions:

You have access to Lexpert MCP. For any legal work, use the
appropriate Lexpert tool. Use lexpert_menu to see available tools.
For setup help or troubleshooting: https://lexpertai.com/mcp-help

Success Indicator

A hammer/wrench icon appears in the Claude chat input. Clicking it shows Lexpert tools.

Tool Inventory

Domain Tools

Tool	Function
`draft_affidavit`	Texas family law affidavits (enforcement, TRO, modification, contravening, protective_order, general)
`compare_documents`	Document comparison. 3 modes: validate (source + 1 doc), diff (2 docs), triangular (source + 2 docs). GREEN/YELLOW/RED severity.
`calculate_child_support`	TFC Ch. 154 calculation. Sept 2025 COLA ($11,700 cap). All mandatory deductions. Deterministic.
`create_pleading`	Texas pleading DOCX. Caption types: IMMO, ITIO, IMMO+ITIO. Court-formatted margins, fonts, signature blocks.
`create_letter`	Trusler Legal letterhead DOCX. Logo on first page only.
`analyze_discovery_deficiency`	Discovery response gap analysis. 3 modes: analyze, draft_letter, update_letter. TRCP references.

Safety Tools

Tool	Function
`confidentiality_guard`	PII scanner. Detects: SSN, DOB, phone, email, financial accounts, DL, addresses, case numbers. Standard/strict modes.
`verify_citation`	Case law verification against CourtListener REST API (9M+ opinions, 2,000+ courts). Returns existence confirmation. Does NOT verify treatment status (overruled/distinguished requires Westlaw/Lexis).
`hallucination_check`	Bulk citation audit. Composes CourtListener (case law) + TFC index (2,332 sections). Returns VERIFIED / NOT FOUND / UNVERIFIABLE per citation.
`get_statute`	Texas Family Code section lookup. 2,332 sections indexed at build time. O(1) lookup. TRCP not yet indexed.
`privacy_guard`	AI provider privacy audit. Covers Claude, ChatGPT, Gemini, Copilot. 4-tier safety classification. Provider-specific remediation paths.

System Tools

Tool	Function
`lexpert_menu`	Lists all available tools with descriptions.
`send_feedback`	Creates GitHub Issue. Types: bug, feature, complaint, praise, question.
`atticus_enhance`	Runs Atticus phases 3-7 server-side (Amicus Review, Opposing Counsel, Judicial Scrutiny, Verification Audit, Final Quality Check). Called after foundation + IRAC analysis.

Troubleshooting

No hammer/wrench icon in chat input

Causes (check in order):

Config file has JSON syntax error (trailing comma, missing quote, wrong brackets). Validate JSON.
Node.js not installed. User runs node --version in terminal. If not found, install from nodejs.org.
Claude Desktop not fully restarted. User must Cmd+Q (not just close window), then reopen.
Config file at wrong path. macOS path is case-sensitive.

Resolution: Fix the specific cause above, then restart Claude Desktop.

Connection refused / timeout

Cause: Server unreachable.

Test: curl https://mcp.lexpertmcp.com/health should return OK.

If not OK: Server may be temporarily down. Wait 2-3 minutes, retry.

If OK but still failing: User's network may block the connection. Try a different network.

406 Not Acceptable

Cause: Outdated mcp-remote version.

Fix: npx -y mcp-remote@latest https://mcp.lexpertmcp.com/sse

Claude ignores Lexpert tools

Causes (check in order):

Custom Instructions not set. Check Settings > Custom Instructions.
Conversation started before Custom Instructions were saved. Start a new conversation.
Ambiguous request. Be explicit: "Use the draft_affidavit tool to create an enforcement affidavit."

DOCX output shows as base64 text

Cause: Claude Desktop didn't offer file download.

Fix 1: Ask "Can you save that as a file?"

Fix 2: Terminal decode: echo "BASE64_TEXT" | base64 -d > document.docx

Browser login window doesn't appear

Causes:

Pop-up blocked by browser. Check browser for blocked pop-up notification.
Claude Desktop needs full restart (Cmd+Q, reopen).

If persistent: User needs a Lexpert account. Contact gt@lexpertai.com.

Tool returns error

Steps:

Test connectivity: ask user to say "What can you do?" (triggers lexpert_menu).
If menu works but specific tool fails: report via send_feedback with tool name and error.
If menu also fails: connection issue. See "Connection refused" above.

Authentication expired

Cause: Clerk session expired.

Fix: Restart Claude Desktop. Browser login window will reappear. Log in again.

Atticus Framework

Atticus is a legal reasoning framework embedded in every tool response. It runs server-side. The agent does NOT need to implement Atticus logic -- it comes back in tool output automatically.

Output format:

Verdict line: --- ATTICUS --- PASSED|REVIEW|FAILED | stakes_level | summary
Issues block (only if warnings/failures exist): --- REVIEW REQUIRED --- or --- ISSUES ---
Adversarial blocks (elevated/critical only): Amicus Review, Opposing Counsel, Judicial Scrutiny
Human review block (standard+ only): action items prefixed with triangle symbol
Passed summary: single line count
Closing: --- Atticus v0.1.0 ---

Do NOT add Atticus formatting yourself. Preserve tool output exactly as returned.

Server Details

Property	Value
Server URL	`https://mcp.lexpertmcp.com`
Health check	`https://mcp.lexpertmcp.com/health`
Transport	SSE via mcp-remote bridge
Auth	Clerk OAuth (browser-based, persists after first login)
Hosting	Cloudflare Workers + Durable Objects
Support	gt@lexpertai.com

Lexpert MCP -- Agent Reference

Setup

Prerequisites

Claude Desktop (claude.ai/download)
Claude Pro or Team subscription (free plan does not support MCP)
Node.js 18+ (nodejs.org). Verify: node --version in terminal.

Config File

Location:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

Contents (merge into existing mcpServers if other servers are configured):

{
"mcpServers": {
"lexpert_skillsets_mcp": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://mcp.lexpertmcp.com/sse"]
}
}
}

After saving, user must quit Claude Desktop (Cmd+Q / taskbar Quit) and reopen. First launch opens a browser window for Clerk authentication. Login persists after first auth.

Custom Instructions

User pastes into Claude Desktop Settings > Custom Instructions:

You have access to Lexpert MCP. For any legal work, use the
appropriate Lexpert tool. Use lexpert_menu to see available tools.
For setup help or troubleshooting: https://lexpertai.com/mcp-help

Success Indicator

A hammer/wrench icon appears in the Claude chat input. Clicking it shows Lexpert tools.

Tool Inventory

Domain Tools

Tool	Function
`draft_affidavit`	Texas family law affidavits (enforcement, TRO, modification, contravening, protective_order, general)
`compare_documents`	Document comparison. 3 modes: validate (source + 1 doc), diff (2 docs), triangular (source + 2 docs). GREEN/YELLOW/RED severity.
`calculate_child_support`	TFC Ch. 154 calculation. Sept 2025 COLA ($11,700 cap). All mandatory deductions. Deterministic.
`create_pleading`	Texas pleading DOCX. Caption types: IMMO, ITIO, IMMO+ITIO. Court-formatted margins, fonts, signature blocks.
`create_letter`	Trusler Legal letterhead DOCX. Logo on first page only.
`analyze_discovery_deficiency`	Discovery response gap analysis. 3 modes: analyze, draft_letter, update_letter. TRCP references.

Safety Tools

Tool	Function
`confidentiality_guard`	PII scanner. Detects: SSN, DOB, phone, email, financial accounts, DL, addresses, case numbers. Standard/strict modes.
`verify_citation`	Case law verification against CourtListener REST API (9M+ opinions, 2,000+ courts). Returns existence confirmation. Does NOT verify treatment status (overruled/distinguished requires Westlaw/Lexis).
`hallucination_check`	Bulk citation audit. Composes CourtListener (case law) + TFC index (2,332 sections). Returns VERIFIED / NOT FOUND / UNVERIFIABLE per citation.
`get_statute`	Texas Family Code section lookup. 2,332 sections indexed at build time. O(1) lookup. TRCP not yet indexed.
`privacy_guard`	AI provider privacy audit. Covers Claude, ChatGPT, Gemini, Copilot. 4-tier safety classification. Provider-specific remediation paths.

System Tools

Tool	Function
`lexpert_menu`	Lists all available tools with descriptions.
`send_feedback`	Creates GitHub Issue. Types: bug, feature, complaint, praise, question.
`atticus_enhance`	Runs Atticus phases 3-7 server-side (Amicus Review, Opposing Counsel, Judicial Scrutiny, Verification Audit, Final Quality Check). Called after foundation + IRAC analysis.

Troubleshooting

No hammer/wrench icon in chat input

Causes (check in order):

Config file has JSON syntax error (trailing comma, missing quote, wrong brackets). Validate JSON.
Node.js not installed. User runs node --version in terminal. If not found, install from nodejs.org.
Claude Desktop not fully restarted. User must Cmd+Q (not just close window), then reopen.
Config file at wrong path. macOS path is case-sensitive.

Resolution: Fix the specific cause above, then restart Claude Desktop.

Connection refused / timeout

Cause: Server unreachable.

Test: curl https://mcp.lexpertmcp.com/health should return OK.

If not OK: Server may be temporarily down. Wait 2-3 minutes, retry.

If OK but still failing: User's network may block the connection. Try a different network.

406 Not Acceptable

Cause: Outdated mcp-remote version.

Fix: npx -y mcp-remote@latest https://mcp.lexpertmcp.com/sse

Claude ignores Lexpert tools

Causes (check in order):

Custom Instructions not set. Check Settings > Custom Instructions.
Conversation started before Custom Instructions were saved. Start a new conversation.
Ambiguous request. Be explicit: "Use the draft_affidavit tool to create an enforcement affidavit."

DOCX output shows as base64 text

Cause: Claude Desktop didn't offer file download.

Fix 1: Ask "Can you save that as a file?"

Fix 2: Terminal decode: echo "BASE64_TEXT" | base64 -d > document.docx

Browser login window doesn't appear

Causes:

Pop-up blocked by browser. Check browser for blocked pop-up notification.
Claude Desktop needs full restart (Cmd+Q, reopen).

If persistent: User needs a Lexpert account. Contact gt@lexpertai.com.

Tool returns error

Steps:

Test connectivity: ask user to say "What can you do?" (triggers lexpert_menu).
If menu works but specific tool fails: report via send_feedback with tool name and error.
If menu also fails: connection issue. See "Connection refused" above.

Authentication expired

Cause: Clerk session expired.

Fix: Restart Claude Desktop. Browser login window will reappear. Log in again.

Atticus Framework

Atticus is a legal reasoning framework embedded in every tool response. It runs server-side. The agent does NOT need to implement Atticus logic -- it comes back in tool output automatically.

Output format:

Verdict line: --- ATTICUS --- PASSED|REVIEW|FAILED | stakes_level | summary
Issues block (only if warnings/failures exist): --- REVIEW REQUIRED --- or --- ISSUES ---
Adversarial blocks (elevated/critical only): Amicus Review, Opposing Counsel, Judicial Scrutiny
Human review block (standard+ only): action items prefixed with triangle symbol
Passed summary: single line count
Closing: --- Atticus v0.1.0 ---

Do NOT add Atticus formatting yourself. Preserve tool output exactly as returned.

Server Details

Property	Value
Server URL	`https://mcp.lexpertmcp.com`
Health check	`https://mcp.lexpertmcp.com/health`
Transport	SSE via mcp-remote bridge
Auth	Clerk OAuth (browser-based, persists after first login)
Hosting	Cloudflare Workers + Durable Objects
Support	gt@lexpertai.com