@username-dev/client

v1.0.2

Published

13 days ago

Official JavaScript SDK for username.dev — the complete solution for username governance

Downloads

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choraria

username validation moderation governance api sdk brand profanity

Overview

username.dev provides a REST API that helps platforms validate and moderate usernames at registration time. Instead of building and maintaining your own profanity filters, brand protection lists, and reserved username databases, you can use our API to get instant results on whether a username should be allowed, flagged, or blocked.

Filter brands, profanity, reserved words, and premium names with a single API call. Stop maintaining blacklists—let the API govern usernames for you.

Features

The username.dev API detects 19+ categories including:

| Category | Description | Example | |----------|-------------|---------| | Brands | Trademarked company names | google, apple, microsoft | | Profanity | Offensive and inappropriate content | — | | Public Figures | Celebrity and influencer names | taylorswift, elonmusk | | Geographic | Cities, countries, and regions | paris, germany, california | | Government | Official agencies and institutions | fbi, cia, whitehouse | | System | Infrastructure and admin terms | admin, root, api | | Premium | High-value short usernames | x, ai, go | | Dictionary | Common English words | hello, world | | First Names | Common given names | john, sarah | | Last Names | Common family names | smith, johnson | | Products | Product names | — | | Companies | Company names | — | | Organizations | Non-profit and other orgs | — | | Agencies | Government agencies | — | | Institutions | Educational and other institutions | — | | Events | Named events | — | | Places | Points of interest | — | | Restricted | Platform-specific blocked terms | — | | Other | Miscellaneous reserved terms | — |

Packages

This monorepo contains two packages:

| Package | Description | npm | |---------|-------------|-----| | @username-dev/client | JavaScript/TypeScript SDK | | | username-dev | Command-line interface | |

Quick Start

1. Get an API Key

Note: You get 1,000 free requests with no credit card required.

2. Install the SDK

npm install @username-dev/client

3. Check a Username

import { UsernameClient } from '@username-dev/client';

const client = new UsernameClient({ 
  apiKey: process.env.USERNAME_DEV_API_KEY 
});

const result = await client.check('taylorswift');

if (result.isReserved) {
  console.log('Username is reserved:', result.categories);
} else {
  console.log('Username is available!');
}

SDK Documentation

SDK Installation

# npm
npm install @username-dev/client

# yarn
yarn add @username-dev/client

# pnpm
pnpm add @username-dev/client

SDK Usage

Basic Usage

import { UsernameClient } from '@username-dev/client';

const client = new UsernameClient({ 
  apiKey: 'un_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' 
});

const result = await client.check('berlin');

console.log(result.username);    // "berlin" (normalized)
console.log(result.isReserved);  // true
console.log(result.isDeleted);   // false
console.log(result.categories);  // [{ category: 'city', metadata: { country: 'DE' } }]

With Custom Base URL

const client = new UsernameClient({ 
  apiKey: 'un_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
  baseUrl: 'https://api.username.dev' // optional, this is the default
});

API Response

interface UsernameCheckResponse {
  /** The normalized username (lowercase, whitespace removed) */
  username: string;
  
  /** Whether the username is reserved (exists in the database) */
  isReserved: boolean;
  
  /** Whether the username has been marked as deleted */
  isDeleted: boolean;
  
  /** Categories associated with this username (empty if not reserved) */
  categories: UsernameCategory[];
}

interface UsernameCategory {
  /** The category name */
  category: 
    | 'brand' | 'city' | 'country' | 'region' | 'place'
    | 'public_figure' | 'government' | 'agency' | 'institution'
    | 'system' | 'restricted' | 'dictionary'
    | 'first_name' | 'last_name'
    | 'product' | 'company' | 'organization'
    | 'event' | 'other';
  
  /** Optional metadata (e.g., country code, language) */
  metadata?: {
    country?: string;  // ISO 3166-1 alpha-2 (e.g., "DE", "US")
    lang?: string;     // Language code (e.g., "en", "de")
  };
}

TypeScript Types

All types are exported from the package:

import type { 
  UsernameClient,
  UsernameClientOptions,
  UsernameCheckResponse, 
  UsernameCategory, 
  CategoryMetadata,
  ProblemDetail 
} from '@username-dev/client';

CLI Documentation

CLI Installation

# Install globally
npm install -g username-dev

# Or use with npx (no installation required)
npx username-dev check <username>

CLI Usage

Set Your API Key

# Set as environment variable
export USERNAME_DEV_API_KEY=un_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

# Or add to your shell profile (~/.bashrc, ~/.zshrc, etc.)
echo 'export USERNAME_DEV_API_KEY=un_live_xxx...' >> ~/.zshrc

Check a Username

username-dev check <username> [options]

Options:

| Option | Description | |--------|-------------| | --json | Output raw JSON instead of formatted text | | --help | Display help information | | --version | Display version number |

CLI Output Examples

Available username:

$ username-dev check randomstring123
✓ randomstring123 is available

Reserved username:

$ username-dev check berlin
✗ berlin is reserved
  Categories: city (DE), government (DE)

Deleted username:

$ username-dev check deleteduser
⚠ deleteduser is reserved (deleted)
  Categories: restricted

JSON output:

$ username-dev check paris --json

{
  "username": "paris",
  "isReserved": true,
  "isDeleted": false,
  "categories": [
    {
      "category": "city",
      "metadata": {
        "country": "FR"
      }
    }
  ]
}

Exit Codes:

| Code | Meaning | |------|---------| | 0 | Username is available | | 1 | Username is reserved or an error occurred |

Error Handling

The SDK throws descriptive errors for common API responses. All errors follow the RFC 7807 Problem Details format.

Error Types

| Status | Error | Description | Action | |--------|-------|-------------|--------| | 400 | Bad Request | Invalid input (empty username, invalid characters) | Fix the input | | 401 | Unauthorized | Invalid API key or account deleted | Check your API key at dashboard | | 402 | Payment Required | Request quota depleted | Purchase more requests at dashboard | | 429 | Too Many Requests | Rate limit exceeded | Wait and retry (see retryAfter in response) | | 503 | Service Unavailable | API temporarily unavailable | Retry later, check status |

Error Handling Example

import { UsernameClient } from '@username-dev/client';

const client = new UsernameClient({ apiKey: process.env.USERNAME_DEV_API_KEY });

try {
  const result = await client.check('username');
  // Handle result
} catch (error) {
  if (error.message.includes('[429]')) {
    // Rate limited - wait and retry
    console.log('Rate limited. Please wait before retrying.');
  } else if (error.message.includes('[402]')) {
    // Quota depleted
    console.log('Quota depleted. Purchase more requests.');
  } else if (error.message.includes('[401]')) {
    // Invalid API key
    console.log('Invalid API key. Check your credentials.');
  } else {
    // Other error
    console.error('Error:', error.message);
  }
}

Security

Warning: Never commit API keys to version control. Always use environment variables.

Best Practices

Use environment variables for API keys:

export USERNAME_DEV_API_KEY=un_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Add .env to .gitignore:
```
echo ".env" >> .gitignore
```

Use .env files for local development:

# .env (do NOT commit this file)
USERNAME_DEV_API_KEY=un_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Use secret management in production (e.g., AWS Secrets Manager, HashiCorp Vault, Vercel Environment Variables)

API Key Format

API keys follow the format: un_live_<32-character-random-string>

Example: un_live_a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6

Requirements

Node.js >= 18.0.0 (for native fetch support)
TypeScript >= 5.0.0 (optional, for type definitions)

Support

Documentation: docs.username.dev
Dashboard: app.username.dev
Status Page: status.username.dev
Email: [email protected]
GitHub Issues: github.com/choraria/username-dev-js/issues

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Fork the repository
Create your feature branch (git checkout -b feature/amazing-feature)
Commit your changes (git commit -m 'Add some amazing feature')
Push to the branch (git push origin feature/amazing-feature)
Open a Pull Request

License

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.