{
"scope": "ListCheck screens list health at three levels: email is checked at domain level (syntax, domain and MX existence, disposable and risk signals - never whether a mailbox exists), phone numbers at numbering-plan level (correctly formed for the country's plan, country and E.164 normalisation - never line reachability or carrier), and card numbers at format level (Luhn checksum, network from the IIN prefix, issued length - never account existence, funds or blocked status).",
"emails": {
"results": [
{
"email": "[email protected]",
"valid": true,
"score": 60,
"verdict": "risky",
"checks": {
"syntax": true,
"domainExists": true,
"mxFound": true,
"disposable": false,
"roleAccount": false,
"freeProvider": false
},
"mxRecords": [
"aspmx.l.google.com",
"alt3.aspmx.l.google.com",
"alt4.aspmx.l.google.com",
"alt1.aspmx.l.google.com",
"alt2.aspmx.l.google.com"
],
"suggestion": "[email protected]",
"typoLikely": true,
"domainAgeDays": 12273,
"domainAgeSource": "RDAP",
"catchAllRisk": "possible",
"note": "Domain accepts mail, but this address looks like a typo of the suggested address. Checks domain mail routing (MX) and risk signals. Does not probe individual mailbox existence. Catch-all risk is a risk signal based on MX/provider patterns, not a probing conclusion."
}
],
"summary": {
"total": 1,
"valid": {
"count": 0,
"percent": 0
},
"risky": {
"count": 1,
"percent": 100
},
"invalid": {
"count": 0,
"percent": 0
},
"disposable": {
"count": 0,
"percent": 0
},
"typoLikely": {
"count": 1,
"percent": 100
}
}
},
"phones": {
"results": [
{
"input": "+14155552671",
"valid": true,
"possible": true,
"country": "US",
"countryCallingCode": "+1",
"nationalNumber": "4155552671",
"e164": "+14155552671",
"internationalFormat": "+1 415 555 2671",
"nationalFormat": "(415) 555-2671",
"type": "FIXED_LINE_OR_MOBILE",
"uri": "tel:+14155552671",
"note": "Type is inferred from numbering plans (MOBILE / FIXED_LINE / TOLL_FREE / etc.). Carrier lookup is not included."
}
],
"summary": {
"total": 1,
"valid_count": 1,
"invalid_count": 0,
"valid_rate": 1,
"invalid_numbers": [],
"by_country": {
"US": 1
},
"by_type": {
"FIXED_LINE_OR_MOBILE": 1
},
"duplicates": [],
"duplicate_count": 0
}
},
"cards": {
"results": [
{
"number": "424242••••••4242",
"bin": "424242",
"last4": "4242",
"length": 16,
"valid": true,
"possible": true,
"checks": {
"luhn": true,
"length": true,
"networkKnown": true
},
"network": "Visa",
"networkId": "visa",
"expectedLengths": [
13,
16,
19
],
"testCard": true
}
],
"summary": {
"total": 1,
"valid": 1,
"invalid": 0
}
},
"summary": {
"total": 3,
"valid": 2,
"notValid": 1,
"legs": {
"email": {
"total": 1,
"valid": 0,
"flagged": 1,
"invalid": 0,
"disposable": 0,
"typoLikely": 1
},
"phone": {
"total": 1,
"valid": 1,
"invalid": 0,
"valid_rate": 1,
"duplicate_count": 0
},
"card": {
"total": 1,
"valid": 1,
"invalid": 0,
"testCards": 1
}
},
"note": "'valid' uses each leg's own verdict: email verdict 'valid' (risky counts as not valid here, see the email leg's summary for the split), phone numbering-plan valid, card format valid. See 'scope' for what each verdict does and does not mean."
}
}
curl --location --request POST 'https://zylalabs.com/api/14773/listcheck+api/38271/screen+batch' --header 'Authorization: Bearer YOUR_API_KEY'
--data-raw '{"emails": ["[email protected]"], "phones": ["+14155552671"], "cards": ["4242424242424242"]}'
{
"type": "email",
"input": "[email protected]",
"result": {
"email": "[email protected]",
"valid": true,
"score": 90,
"verdict": "valid",
"checks": {
"syntax": true,
"domainExists": true,
"mxFound": true,
"disposable": false,
"roleAccount": true,
"freeProvider": true
},
"mxRecords": [
"alt3.gmail-smtp-in.l.google.com",
"gmail-smtp-in.l.google.com",
"alt4.gmail-smtp-in.l.google.com",
"alt1.gmail-smtp-in.l.google.com",
"alt2.gmail-smtp-in.l.google.com"
],
"suggestion": null,
"typoLikely": false,
"domainAgeDays": 11410,
"domainAgeSource": "RDAP",
"catchAllRisk": "low",
"note": "Domain-level validation only: syntax, domain/MX health, disposable and provider risk. Mailbox existence is not probed (no SMTP check), so a valid result does not confirm the mailbox exists. The score is a domain risk score.",
"scope": "domain-level"
},
"scope": "ListCheck screens list health at three levels: email is checked at domain level (syntax, domain and MX existence, disposable and risk signals - never whether a mailbox exists), phone numbers at numbering-plan level (correctly formed for the country's plan, country and E.164 normalisation - never line reachability or carrier), and card numbers at format level (Luhn checksum, network from the IIN prefix, issued length - never account existence, funds or blocked status)."
}
curl --location --request POST 'https://zylalabs.com/api/14773/listcheck+api/38272/screen+single' --header 'Authorization: Bearer YOUR_API_KEY'
--data-raw '{"type": "email", "value": "[email protected]"}'
{
"ok": true,
"service": "ListCheck",
"version": 1
}
curl --location --request GET 'https://zylalabs.com/api/14773/listcheck+api/38273/health+check' --header 'Authorization: Bearer YOUR_API_KEY'
After signing up, every developer is assigned a personal API access key, a unique combination of letters and digits provided to access to our API endpoint. To authenticate with the ListCheck API simply include your bearer token in the Authorization header.
| Header | Description |
|---|---|
Authorization
|
Required
Should be Bearer access_key. See "Your API Access Key" above when you are subscribed.
|
No long-term commitment. Upgrade, downgrade, or cancel anytime.
Screen a whole list in one call: email addresses, phone numbers and card numbers checked together, per-item results plus one health summary. Batch up to 100 per leg.
No. The email leg checks domain mail routing (MX), registration data and risk signals. Mailbox-level probing is unreliable, so we do not do it and do not claim it.
No. It means the number is correctly formed under its country's numbering plan — right length, allocated prefix patterns. Whether the line is assigned or reachable, and which carrier serves it, cannot be known from parsing.
No. The card leg validates format only: check digit, recognised network, issued length. Whether an account exists, has funds, or is blocked is known only to the issuer, and no issuer, bank, country or card-type data is returned.
Nothing breaks. A bad entry comes back in its own result slot, marked invalid with the reason, while every other item is screened normally and the summaries still tally the whole list.
Yes. POST /screen/single takes {"type": "email" | "phone" | "card", "value": "..."} — built for form validation at signup or checkout.
To obtain your API key, first sign in to your account and navigate to the API you want to use. From the API's Pricing section, choose a plan and complete the subscription process. Once subscribed, return to the API page and you will see your API Access Key displayed at the top of the documentation page. You can use this key to authenticate your requests.
You can’t switch APIs during the free trial. If you subscribe to a different API, your trial will end and the new subscription will start as a paid plan.
The free trial lasts for 7 days and allows you to make up to 50 API requests.
No, the free trial is available only once, so we recommend using it on the API that interests you the most. Most of our APIs offer a free trial, but some may not include this option.
Yes. If the API offers a free trial, you will see a "Free 7-Day Trial" option in its Pricing section. The trial lasts for 7 days and allows up to 50 API requests, enabling you to evaluate the API before subscribing to a paid plan.
Zyla API Hub is like a big store for APIs, where you can find thousands of them all in one place. We also offer dedicated support and real-time monitoring of all APIs. Once you sign up, you can pick and choose which APIs you want to use. Just remember, each API needs its own subscription. But if you subscribe to multiple ones, you'll use the same key for all of them, making things easier for you.
You can monitor your API usage through the response headers included with every request:
x-zyla-api-calls-monthly-used: Shows the total number of API requests you have used during the current billing period.
x-zyla-api-calls-monthly-remaining: Shows the number of API requests you have remaining for the current billing period.
Yes, you can cancel your subscription at any time. Simply go to the Pricing section of the API you're subscribed to and click the "Unsubscribe" button.
Please note that upgrades, downgrades, and cancellations take effect immediately. Once your subscription is canceled, access to the service will end immediately, regardless of any remaining API calls in your quota.
Please have a look at our Refund Policy: https://zylalabs.com/terms#refund