> ## Documentation Index
> Fetch the complete documentation index at: https://docs.autosend.com/llms.txt
> Use this file to discover all available pages before exploring further.

# API Best Practices

> Security and development best practices for using the AutoSend email API.

export const APP_PATHS = {
  home: '/',
  quickstart: '/quickstart',
  domainConfiguration: '/domain',
  apiReference: '/api-reference',
  sendEmail: '/api-reference/mails/send',
  bulkSendEmail: '/api-reference/mails/bulk',
  upsertContactApiRef: '/api-reference/contacts/upsert-contact',
  transactional: '/transactional-emails',
  emailActivity: '/transactional-emails/email-activity',
  emailTemplates: '/transactional-emails/email-templates',
  sendingEmail: '/quickstart/email-using-api',
  transactionalTroubleshooting: '/transactional-emails/troubleshooting',
  marketing: '/marketing-emails',
  campaigns: '/marketing-emails/campaigns',
  contacts: '/marketing-emails/contacts',
  contactsIntroduction: '/marketing-emails/contacts/introduction',
  contactsImportCsv: '/marketing-emails/contacts/import-csv',
  contactsLists: '/marketing-emails/contacts/lists',
  contactsSegments: '/marketing-emails/contacts/segments',
  contactsCustomFields: '/marketing-emails/contacts/custom-fields',
  sender: '/marketing-emails/sender',
  unsubscribeGroups: '/others/unsubscribe-groups',
  webhookIntroduction: '/others/webhooks/introduction',
  webhookEventType: '/others/webhooks/event-type',
  webhookRetries: '/others/webhooks/retries',
  webhookVerifyRequests: '/others/webhooks/verify-requests',
  dynamicTemplates: '/dynamic-templates',
  guides: '/guides',
  sitemap: '/sitemap.xml',
  team: '/others/team',
  automations: '/automations',
  smtpIntroduction: '/quickstart/smtp',
  betterAuth: '/guides/better-auth',
  templateVariables: '/transactional-emails/variables',
  suppressions: '/others/suppressions',
  rateLimit: '/api-reference/rate-limit',
  nodejsSdk: '/sdk/nodejs',
  smtpIntegrationGuides: '/guides/smtp',
  apiKeys: '/api-keys',
  apiReferenceIntroduction: '/api-reference/introduction',
  lovableGuide: '/ai/integrations/lovable',
  aiIntroduction: '/ai/introduction',
  aiSkills: '/ai/skills',
  aiMcpServer: '/ai/mcp-server',
  aiLovable: '/ai/integrations/lovable',
  aiBolt: '/ai/integrations/bolt',
  aiV0: '/ai/integrations/v0',
  aiReplit: '/ai/integrations/replit',
  mcpClaude: '/ai/mcp-clients/claude',
  mcpCursor: '/ai/mcp-clients/cursor',
  mcpCopilot: '/ai/mcp-clients/copilot',
  mcpWindsurf: '/ai/mcp-clients/windsurf',
  mcpCodex: '/ai/mcp-clients/codex',
  mcpAntigravity: '/ai/mcp-clients/antigravity',
  mcpChatgpt: '/ai/mcp-clients/chatgpt',
  mcpRaycast: '/ai/mcp-clients/raycast',
  domainWarmup: '/marketing-emails/domain-warmup',
  projects: '/projects',
  createAutomationApi: '/api-reference/automations/create-automation'
};

### 1. Use Environment Variables

Never hardcode API keys in your source code:

```javascript theme={null}
const API_KEY = process.env.AUTOSEND_API_KEY;
```

### 2. Implement Error Handling

Always handle errors appropriately:

```javascript theme={null}
try {
  const response = await sendEmail(data);
  console.log("Email sent:", response.data.emailId);
} catch (error) {
  if (error.response?.status === 429) {
    // Rate limit - retry later
  } else if (error.response?.status === 400) {
    // Validation error - fix the data
  } else {
    // Other error - log and alert
  }
}
```

### 3. Validate Email Addresses

Validate email addresses before sending to reduce bounces:

```javascript theme={null}
function isValidEmail(email) {
  const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
  return emailRegex.test(email);
}
```

### 4. Use Verified Domains

Always send from verified domains to ensure deliverability. <a href={APP_PATHS.domainConfiguration} title="Domain configuration">Learn how to verify domains →</a>

### 5. Include Unsubscribe Links

For marketing emails, always include unsubscribe links to comply with regulations and maintain good sender reputation. You can use `{{unsubscribe}}` and `{{unsubscribe_preference}}` variable tags in your email template to dynamically insert unsubscribe link.
<Tip>Many people confuse transactional and marketing emails, especially when it comes to unsubscribe links. To clear things up, we’ve covered [whether transactional emails need an unsubscribe link](https://autosend.com/blog/do-transactional-emails-need-an-unsubscribe-link) in detail.</Tip>