PIN Generator API: Generate Secure Numeric Codes

Need to generate secure PIN codes for verification, authentication, or access control? The PIN Generator API creates cryptographically random numeric codes of any length, perfect for OTPs, ATM pins, and two-factor authentication systems.

What is a PIN Code?

A PIN (Personal Identification Number) is a numeric code used for authentication and verification. PINs are widely used in banking, mobile devices, security systems, and two-factor authentication flows.

Common PIN lengths include 4 digits (10,000 combinations), 6 digits (1 million combinations), and 8 digits (100 million combinations). Longer PINs provide significantly more security against brute-force attacks.

Security Considerations

When generating PINs, several security factors matter:

Randomness Quality

PINs must be generated using cryptographically secure random number generators (CSPRNG), not standard pseudo-random functions.

Avoiding Patterns

Optionally exclude sequential numbers (1234), repeated digits (1111), and other easily guessable patterns.

Length Requirements

Longer PINs are exponentially harder to guess. A 6-digit PIN has 100x more combinations than a 4-digit PIN.

Using the PIN Generator API

TinyFn provides a simple endpoint to generate secure PINs:

GET https://api.tinyfn.io/v1/generate/pin?length=6
Headers: X-API-Key: your-api-key

{
  "pin": "847293",
  "length": 6,
  "entropy_bits": 19.93
}

Parameters

Code Examples

JavaScript / Node.js

const response = await fetch(
  'https://api.tinyfn.io/v1/generate/pin?length=6&exclude_sequential=true',
  { headers: { 'X-API-Key': 'your-api-key' } }
);
const { pin } = await response.json();
console.log(`Verification code: ${pin}`); // 847293

Python

import requests

response = requests.get(
    'https://api.tinyfn.io/v1/generate/pin',
    headers={'X-API-Key': 'your-api-key'},
    params={'length': 6, 'exclude_sequential': True}
)
pin = response.json()['pin']
print(f"Your OTP is: {pin}")

cURL

curl "https://api.tinyfn.io/v1/generate/pin?length=6" \
  -H "X-API-Key: your-api-key"

Common Use Cases

• Email/SMS Verification: Send one-time codes for account verification
• Two-Factor Authentication: Generate TOTP-style backup codes
• Banking Applications: Create temporary ATM or card PINs
• Access Control: Generate door codes for temporary access
• Order Pickup: Create pickup verification codes for e-commerce

Best Practices

1. Use appropriate length: 6+ digits for sensitive operations
2. Set expiration times: OTPs should expire within 5-10 minutes
3. Limit attempts: Lock accounts after 3-5 failed PIN entries
4. Avoid patterns: Enable pattern exclusion for predictable-resistant codes
5. Secure transmission: Send PINs over encrypted channels only

Use via MCP

Your AI agent can call this tool directly via Model Context Protocol — no HTTP code needed. Add TinyFn to Claude Desktop, Cursor, or any MCP client:

{
  "mcpServers": {
    "tinyfn-generate": {
      "url": "https://api.tinyfn.io/mcp/generate/",
      "headers": {
        "X-API-Key": "your-api-key"
      }
    }
  }
}

See all generator tools available via MCP in our Generator MCP Tools for AI Agents guide.