API Security Best Practices for Mobile Developers
Securing your API integration is critical for protecting user data and maintaining service reliability. This guide covers essential security practices for working with APIs like REGHelp.
Authentication
API Key Management
- Store API keys in environment variables, never in source code
- Use different keys for development, staging, and production
- Rotate keys periodically (every 90 days recommended)
- Monitor key usage for anomalous patterns
HTTPS Only All API communication must use HTTPS. Never send API keys or tokens over unencrypted HTTP connections.
Rate Limiting
- Implement client-side rate limiting to avoid hitting server limits
- Use exponential backoff for retries (1s, 2s, 4s, 8s, max 30s)
- Cache successful responses when appropriate
- Monitor
X-RateLimit-Remainingheaders
Token Handling
- Never log tokens at INFO level — use DEBUG only in development
- Set appropriate TTLs and refresh tokens before expiry
- Validate token format before using them
- Implement token revocation in your error handling
Input Validation
- Validate all user input before sending to API
- Use strict type checking for API parameters
- Sanitize URLs to prevent SSRF attacks
- Validate callback URLs against an allowlist
Error Handling
- Never expose internal error details to end users
- Log errors securely (no tokens, no credentials in logs)
- Implement circuit breakers for API calls
- Have fallback behavior when the API is unavailable
Monitoring
- Track API response times and error rates
- Set up alerts for unusual patterns (spike in errors, slow responses)
- Monitor balance and set low-balance alerts
- Review API usage logs regularly