API Documentation

Everything you need to integrate 1Lookup's data validation platform. Simple REST API, sub-300ms response times, 99.97% accuracy.

Quick Start

Get started in under 5 minutes

// Install the SDK (optional)
npm install @1lookup/sdk

// Or use standard fetch
const response = await fetch('https://api.1lookup.io/v1/validate/phone', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    phone: '+14155552671',
    include_fraud_score: true
  })
})

const data = await response.json()
console.log(data)

Authentication

Base URL

https://api.1lookup.io/v1

Authentication Header

Authorization: Bearer YOUR_API_KEY

Note: API keys start with 1lk_ and are 32 characters long. Keep your keys secure and never expose them in client-side code.

API Endpoints

Phone Validation

3 tokens

POST /v1/validate/phone

Validate phone numbers with fraud scoring and carrier data

Request

{
  "phone": "+14155552671",
  "country": "US",
  "include_fraud_score": true
}

Response

{
  "number": "4155552671",
  "carrier": "Verizon Wireless",
  "line_type": "mobile",
  "valid": true,
  "fraud_score": 15,
  "risk_level": "low",
  "dnc_registered": false,
  "ported": false,
  "tokens_used": 3
}

Phone Spam Check

2 tokens

POST /v1/check/phone-spam

Analyze phone numbers for spam, fraud, and robocall risks

Request

{
  "phone": "+14155552671",
  "include_fraud_analysis": true
}

Response

{
  "phone_number": "4155552671",
  "spam_score": 22,
  "user_reputation": "Positive",
  "robo_status": "Allowed",
  "complaint_count": 0,
  "last_complaint": null,
  "fraud_campaigns": [],
  "spoofing_risk": "low",
  "scam_type_predictions": [],
  "industry_blacklists": [],
  "tokens_used": 2
}

Email Validation

1 token

POST /v1/validate/email

Verify email deliverability and detect disposable addresses

Request

{
  "email": "john.doe@example.com",
  "check_deliverability": true
}

Response

{
  "email": "john.doe@example.com",
  "valid": true,
  "deliverable": true,
  "disposable": false,
  "role": false,
  "fraud_score": 5,
  "tokens_used": 1
}

IP Lookup

1 token

POST /v1/lookup/ip

Get IP intelligence with proxy/VPN detection

Request

{
  "ip": "192.168.1.1",
  "include_fraud_detection": true
}

Response

{
  "ip": "192.168.1.1",
  "country": "United States",
  "city": "San Francisco",
  "proxy": false,
  "vpn": false,
  "fraud_score": 8,
  "tokens_used": 1
}

SDKs & Libraries

JavaScript/Node.js

Available

npm install @1lookup/js

Python

Available

pip install 1lookup

PHP

Coming Soon

Rate Limits & Error Codes

Rate Limits

Default1,000 requests/minute

Business+5,000 requests/minute

ScaleCustom limits

HTTP Status Codes

200Success

400Bad Request

401Unauthorized

429Rate Limited

500Server Error