Features

• 🚀 TypeScript SDK - Fully typed client for all eCFR API endpoints
• 🤖 MCP Server - AI-ready server for integration with Claude and other AI assistants
• 🔄 Auto-generated - Automatically updated from the official eCFR OpenAPI specification
• 📦 Modern tooling - Built with Bun, Biome, and Orval
• 🐳 Docker support - Ready-to-use Docker image for the MCP server
• ✨ Tree-shakeable - Only import what you need
• 🔍 Type-safe - Full TypeScript support with auto-completion
• ⚡ Fast - Optimized for performance with minimal dependencies

Installation

# npm
npm install @us-legal-tools/ecfr-sdk

# yarn
yarn add @us-legal-tools/ecfr-sdk

# pnpm
pnpm add @us-legal-tools/ecfr-sdk

# bun
bun add @us-legal-tools/ecfr-sdk

Quick Start

Basic Usage

import { getApiSearchV1Results, getApiVersionerV1TitlesJson } from '@us-legal-tools/ecfr-sdk';

// Search for regulations
const searchResults = await getApiSearchV1Results({
  query: 'environmental protection',
  per_page: 10,
  page: 1
});

console.log(`Found ${searchResults.meta.total_count} regulations`);
searchResults.results.forEach(result => {
  console.log(`- Title ${result.hierarchy.title}: ${result.hierarchy_headings.join(' > ')}`);
});

// Get all available titles
const titles = await getApiVersionerV1TitlesJson();
console.log(`Available titles: ${titles.titles.length}`);

Advanced Search

import { getApiSearchV1Results } from '@us-legal-tools/ecfr-sdk';

// Search with filters
const results = await getApiSearchV1Results({
  query: 'clean air',
  title: 40, // Title 40: Protection of Environment
  part: 50,  // Part 50
  date: '2024-01-01',
  condition: 'AND',
  per_page: 20
});

// Access faceted search metadata
console.log('Search facets:', results.meta?.facets);

Historical Versions

import { getApiVersionerV1FullDateTitleTitleXml } from '@us-legal-tools/ecfr-sdk';

// Get a specific version of a regulation
const historicalVersion = await getApiVersionerV1FullDateTitleTitleXml(
  '2023-01-01',  // date
  '40',           // title
  {
    part: '50',
    section: '7'
  }
);

// Note: Large titles (like Title 29) may timeout when fetching the entire XML.
// Consider fetching specific parts or sections instead.

API Reference

Search Endpoints

• getApiSearchV1Results - Search all regulations
• getApiSearchV1Count - Get search result count
• getApiSearchV1Summary - Get search summary
• getApiSearchV1CountsDaily - Get daily search counts
• getApiSearchV1CountsTitles - Get search counts by title
• getApiSearchV1CountsHierarchy - Get hierarchical search counts
• getApiSearchV1Suggestions - Get search suggestions

Versioning Endpoints

• getApiVersionerV1TitlesJson - Get all available titles
• getApiVersionerV1FullDateTitleTitleXml - Get full regulation text
• getApiVersionerV1StructureDateTitleTitleJson - Get regulation structure
• getApiVersionerV1VersionsTitleTitleJson - Get available versions
• getApiVersionerV1AncestryDateTitleTitleJson - Get regulation ancestry

Admin Endpoints

• getApiAdminV1AgenciesJson - Get all agencies
• getApiAdminV1CorrectionsJson - Get all corrections
• getApiAdminV1CorrectionsTitleTitleJson - Get corrections for a title

MCP Server

The MCP server allows AI assistants to interact with the eCFR API.

Running the Server

# Using the SDK directly
npx @us-legal-tools/ecfr-sdk/mcp

# Or if installed locally
cd node_modules/@us-legal-tools/ecfr-sdk
npm run mcp:server

Docker Support

# Pull and run the Docker image
docker run -i ghcr.io/beshkenadze/ecfr-mcp-server:latest

Integration with Claude

Add to your Claude configuration:

{
  "mcpServers": {
    "ecfr": {
      "command": "npx",
      "args": ["@us-legal-tools/ecfr-sdk/mcp"]
    }
  }
}

Error Handling

import { getApiSearchV1Results } from '@us-legal-tools/ecfr-sdk';

try {
  const results = await getApiSearchV1Results({
    query: 'search term',
    per_page: 10
  });
} catch (error) {
  if (error.response?.status === 400) {
    console.error('Invalid search parameters');
  } else if (error.response?.status === 429) {
    console.error('Rate limit exceeded');
  } else {
    console.error('API error:', error.message);
  }
}

Configuration

The SDK uses axios under the hood. You can access and modify the axios instance:

import { axiosInstance } from '@us-legal-tools/ecfr-sdk';

// Add request interceptor
axiosInstance.interceptors.request.use(config => {
  console.log('Making request to:', config.url);
  return config;
});

// Modify timeout
axiosInstance.defaults.timeout = 60000; // 60 seconds

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Links

• npm Package
• GitHub Repository
• eCFR Website
• eCFR API Documentation
• Report Issues
• Request Features

Support

Need help? Check out our documentation or create an issue.