Introduction to LexBuild

LexBuild is a toolchain that converts U.S. legal source data into structured Markdown optimized for AI ingestion, retrieval-augmented generation (RAG) systems, semantic search, and legal research.

Core Interfaces

LexBuild provides four primary methods for accessing and processing legal content:

• CLI: A command-line tool to download and convert legal XML sources locally, outputting standalone Markdown files with structured YAML frontmatter.
• API: A REST API for programmatic access to legal content, supporting content negotiation for JSON, Markdown, and plaintext responses.
• MCP Server: A Model Context Protocol server that gives AI assistants direct access to U.S. legal sources. Works with Claude Desktop, Claude Code, Cursor, Codex CLI, Copilot CLI, Gemini CLI, VS Code, Zed, Warp, and many others.
• Web: A browser-based interface to navigate, search, and read the U.S. Code, Code of Federal Regulations, and Federal Register as rendered Markdown at lexbuild.dev.

Supported Sources

Documentation Overview

This documentation is structured to support different integration paths:

• Getting Started: Quickstarts for the CLI, API, Web, and MCP server.
• CLI: Installation, commands, source-specific workflows, and output format specifications.
• Web: Browsing, advanced search, and content extraction.
• API: Authentication, endpoints, content negotiation, and pagination details.
• MCP: Installation for popular AI clients, tool and resource reference, and security details.
• User Guides: Implementation strategies for RAG pipelines, bulk downloading, and legal research.
• Architecture: Internal mechanics of the XML-to-Markdown conversion pipeline.
• Reference: Comprehensive specifications for identifiers, metadata schemas, and XML element mappings.
• Project: Contributing guidelines, changelog, and license.

[!TIP] To evaluate the conversion output immediately, start with the CLI Quickstart.