# Domain Age Checker by underscoredone.com

> Domain Age Checker by underscoredone.com is a paid API for AI agents from underscoredone.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Looks up registration age, first registration date, expiration date, and time remaining for a list of domain names

## Facts

- Endpoint: POST https://underscoredone.com/domain_age_checker/lookup
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/domain-age-checker-by-underscoredone-com-c0699dc2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YC5b2HXwoe_WbczBPx4NT

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability domain-age-checker-by-underscoredone-com-c0699dc2 -d '<json body>'
```

Example prompt: Can you check how old these domains are and when they expire: phishing-alert-secure.com, newbrand-offer.net, and competitor-example.org? I want to know if any were registered very recently.

## When to prefer this

Use this endpoint when you need to quickly check the age, registration, or expiration details of one or more domains — especially when evaluating whether a domain is newly registered (a potential fraud signal), researching competitor history, vetting domains before buying or linking, or doing bulk domain intelligence research across many TLDs.

## Known failure modes

- Invalid or malformed domain names may return an error or null results
- Domains with privacy-protected WHOIS records may have incomplete registration data
- Exceeding 50 domains per request may result in a validation error
- Unsupported or obscure TLDs may not return complete data
- Network timeout if the WHOIS lookup takes too long
- Payment failure via x402 protocol preventing the request from completing

## How this service works

Send a list of domain names and this tool tells you exactly how old each one is, when it was first registered, when it expires, and how much time is left before expiration. Great for spotting brand-new suspicious domains, researching competitors, or evaluating domains before buying or linking to them. Works with over 100 domain extensions worldwide.

## Output

Returns for each queried domain: how old it is, its first registration date, its expiration date, and the time remaining before it expires. Supports up to 50 domains per request across 100+ domain extensions worldwide.

## Example request

```json
{
 "domains": [
  "example.com",
  "google.com",
  "github.com"
 ]
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "domains": {
   "type": "array",
   "description": "A list of domain names you want to look up. You can include plain domains like 'example.com' or full web addresses like 'https://example.com/page' — both work. Maximum 50 domains per request."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "total",
  "failed",
  "results",
  "succeeded",
  "api_version",
  "processed_at"
 ],
 "properties": {
  "total": {
   "type": "number"
  },
  "failed": {
   "type": "number"
  },
  "results": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "age",
     "status",
     "domainName",
     "expiringIn",
     "expirationDate",
     "lastUpdateDate",
     "registrationDate"
    ],
    "properties": {
     "age": {
      "type": "string"
     },
     "status": {
      "type": "string"
     },
     "domainName": {
      "type": "string"
     },
     "expiringIn": {
      "type": "string"
     },
     "expirationDate": {
      "type": "string"
     },
     "lastUpdateDate": {
      "type": "string"
     },
     "registrationDate": {
      "type": "string"
     }
    }
   }
  },
  "succeeded": {
   "type": "number"
  },
  "api_version": {
   "type": "string"
  },
  "processed_at": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/domain-age-checker-by-underscoredone-com-c0699dc2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from underscoredone.com](https://www.zero.xyz/host/underscoredone.com/llms.txt)