ZelNum API overview

Example request pattern

Use server-side API keys and keep credentials out of browsers, mobile apps, and public repositories. Replace the product slug with the one listed in the live app docs or returned by GET /api/v1/products, which needs no key.

curl -X POST "https://api.zelnum.com/api/v1/detect" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "product": "phone-status-check",
    "country": "US",
    "phones": ["+13125550731", "+442071838750"]
  }'

Single-number checks

For one-off checks that should return in the same call, use the realtime endpoint. It accepts one phone number or one email together with up to ten realtime product ids from the same series, and requires an Idempotency-Key so a retry never bills twice.

curl -X POST "https://api.zelnum.com/api/v1/realtime/check/phone" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Idempotency-Key: 6f1c2b7e-4d3a-4f8e-9c21-0b5a7d2e9f10" \
  -H "Content-Type: application/json" \
  -d '{"identifier":"+13125550731","country":"US","product_ids":[47]}'

Task result flow

• POST /api/v1/detect/file uploads CSV or TXT files.
• GET /api/v1/products lists every product with its series and minimum quantity.
• GET /api/v1/tasks/{task_id}/result returns the download URL.
• GET /api/v1/balance checks account balance.
• GET /api/v1/tasks/{task_id} checks progress.
• POST /api/v1/detect submits phone arrays.

Machine-readable contract

The full contract is published as an OpenAPI 3.1 document at zelnum.com/openapi.yaml. It carries every path, the security schemes, the complete business error-code enum, and the rate-limit headers, so it can drive SDK generation, Postman collections, and API tooling without scraping the documentation page.

Important limitations

API results are verification and data quality signals. Coverage, confidence, and response fields can vary by country, product, source, and identifier quality. ZelNum does not prove identity or replace legal, consent, or compliance review.