Vaquill

MCP server for Vaquill legal research API. Covers US federal and 50-state law (USC, CFR, state legislation, CourtListener case law). Ask AI-powered legal questions, search statutes, and ground answers in primary sources, all from your AI tools.

Quick Start

Prerequisites

Sign up at vaquill.ai to get your API key.

Claude.ai (Web)

No installation needed. Add as a remote MCP server in Claude.ai Settings > Integrations:

Option A: Simple URL (API key in path)

https://mcp.vaquill.ai/s/vq_key_your_key_here

Option B: Bearer token (recommended)

URL:   https://mcp.vaquill.ai/s/_
Token: vq_key_your_key_here

Available on Claude Pro, Max, Team, and Enterprise plans.

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "vaquill": {
      "command": "uvx",
      "args": ["vaquill-mcp"],
      "env": {
        "VAQUILL_API_KEY": "vq_key_your_key_here"
      }
    }
  }
}

Claude Code

Remote (no install):

claude mcp add-json vaquill '{"type":"http","url":"https://mcp.vaquill.ai/s/_","headers":{"Authorization":"Bearer vq_key_your_key_here"}}'

Local (via uvx):

claude mcp add vaquill -- uvx vaquill-mcp
# Then set the env var in your shell: export VAQUILL_API_KEY=vq_key_...

Or add to .claude/settings.json:

{
  "mcpServers": {
    "vaquill": {
      "command": "uvx",
      "args": ["vaquill-mcp"],
      "env": {
        "VAQUILL_API_KEY": "vq_key_your_key_here"
      }
    }
  }
}

Cursor

Add to Cursor Settings > MCP Servers:

{
  "mcpServers": {
    "vaquill": {
      "command": "uvx",
      "args": ["vaquill-mcp"],
      "env": {
        "VAQUILL_API_KEY": "vq_key_your_key_here"
      }
    }
  }
}

VS Code (Copilot)

Add to .vscode/settings.json:

{
  "mcp": {
    "servers": {
      "vaquill": {
        "command": "uvx",
        "args": ["vaquill-mcp"],
        "env": {
          "VAQUILL_API_KEY": "vq_key_your_key_here"
        }
      }
    }
  }
}

Windsurf

Add to ~/.windsurf/settings.json:

{
  "mcpServers": {
    "vaquill": {
      "command": "uvx",
      "args": ["vaquill-mcp"],
      "env": {
        "VAQUILL_API_KEY": "vq_key_your_key_here"
      }
    }
  }
}

Available Tools

General

Tool	Description	Credits
ask_legal_question	AI-powered legal Q&A across USC, CFR, 50-state law, and CourtListener case law. Standard (fast) or deep (multi-hop) modes.	5 - 20
get_pricing	Get current API credit pricing (no auth required).	Free

US law (USC + CFR)

Tool	Description	Credits
search_us_statutes	Semantic search across the United States Code (USC) and Code of Federal Regulations (CFR). Filter by corpusType and titleNumber.	2
get_us_statute_section	Metadata for a specific USC/CFR section by act_id (citation, title hierarchy, links).	1
get_us_statute_section_text	Full HTML + plain text of a USC or CFR section.	3

Environment Variables

Variable	Required	Default	Description
VAQUILL_API_KEY	Yes	-	API key (vq_key_...) from vaquill.ai
VAQUILL_BASE_URL	No	https://api.vaquill.ai	API base URL
VAQUILL_TIMEOUT	No	120	Request timeout in seconds

Example Usage

Once configured, you can ask your AI assistant things like:

• "What does 17 CFR 240.10b-5 say about insider trading?"
• "Find USC sections on equal protection under the Fourteenth Amendment"
• "Summarize FRCP Rule 12(b)(6) and recent SDNY case law applying it" (uses deep mode)
• "What are the federal penalties for wire fraud under 18 USC 1343?"

Development

# Clone and install
git clone https://github.com/Vaquill-AI/vaquill-mcp.git
cd vaquill-mcp
uv sync --all-extras

# Run locally
VAQUILL_API_KEY=vq_key_... uv run vaquill-mcp

# Run tests
uv run pytest

# Test with FastMCP inspector
uv run fastmcp dev src/vaquill_mcp/server.py

How It Works

This package is a thin MCP wrapper around the Vaquill Developer API. At startup, it fetches the OpenAPI spec from the live API and auto-generates MCP tools using FastMCP. Tool names and descriptions are customized for optimal LLM performance.

Because the spec is fetched at startup (not bundled), tools automatically reflect any API changes without a package update.

Credits & Pricing

API calls consume credits. Check current pricing at vaquill.ai or use the get_pricing tool.

1 credit = $0.10 USD

Data Attribution

US case law is sourced from CourtListener, maintained by the Free Law Project.

License

MIT