Overview
Pass a root domain to query certificate transparency entries and common hostnames in real time. The response pairs each discovered host with its resolved IP addresses, including root domain records and a completion status flag. When queries hit the scan time limit, a note explains truncation. Paid plans can increase detection limits and enable deep wordlist scans.
Live Test Subdomain Finder Skill Skill →
The tool
Once your client is connected to the VerveKit server, this appears in its tool list as SubdomainFinderSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.
{
"name": "SubdomainFinderSkill",
"arguments": {
"domain": "google.com"
}
}You do not name the tool yourself; the model picks it. Asking about google.com in the terms this skill covers is enough for it to reach for SubdomainFinderSkill on its own — naming it explicitly also works, and is the way to force the call.
Connecting
One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.
{
"mcpServers": {
"vervekit": {
"url": "https://api.vervekit.com/v1/mcp"
}
}
}https://api.vervekit.com/v1/mcpPer-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.
Arguments
These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.
| Argument | Type | Description |
|---|---|---|
domainRequired | string | The domain you want to find all the available subdomains for (e.g. google.com) domain |
limitOptionalPremium | integer | Limit the number of subdomains to detect default 10 · range 1–500 |
deepScanOptionalPremium | boolean | Search the full wordlist instead of only certificate transparency and common names. Slower, and may still report complete: false when the time limit is reached |
What the model gets back
The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.
{
"status": "ok",
"error": null,
"data": {
"rootDomain": {
"domain": "paypal.com",
"records": [
"151.101.3.1",
"151.101.195.1",
"162.159.141.96"
]
},
"subDomains": [
{
"host": "api.paypal.com",
"records": [
"66.211.168.123"
]
},
{
"host": "mail.paypal.com",
"records": [
"159.127.187.12"
]
},
{
"host": "admin.paypal.com",
"records": [
"173.0.88.10"
]
},
{
"host": "smtp.paypal.com",
"records": [
"64.4.244.68"
]
},
{
"host": "ns2.paypal.com",
"records": [
"64.4.244.71"
]
},
{
"host": "test.paypal.com",
"records": [
"156.59.125.88"
]
},
{
"host": "ns1.paypal.com",
"records": [
"64.4.244.70"
]
},
{
"host": "mx.paypal.com",
"records": [
"10.190.3.55"
]
},
{
"host": "demo.paypal.com",
"records": [
"151.101.1.21",
"151.101.193.21",
"151.101.129.21",
"151.101.65.21"
]
},
{
"host": "shop.paypal.com",
"records": [
"54.148.26.111",
"35.80.170.143",
"54.212.145.128"
]
},
{
"host": "www.paypal.com",
"records": [
"151.101.193.21",
"151.101.65.21",
"151.101.129.21",
"151.101.1.21"
]
},
{
"host": "m.paypal.com",
"records": [
"151.101.129.21",
"151.101.1.21",
"151.101.193.21",
"151.101.65.21"
]
},
{
"host": "stage.paypal.com",
"records": [
"64.4.241.16"
]
},
{
"host": "ssl.paypal.com",
"records": [
"151.101.65.21",
"151.101.129.21",
"151.101.193.21",
"151.101.1.21"
]
},
{
"host": "i.paypal.com",
"records": [
"63.140.38.107",
"63.140.39.244",
"63.140.39.114",
"63.140.38.116",
"63.140.39.254",
"63.140.39.146",
"63.140.38.213",
"63.140.39.214",
"63.140.39.87",
"63.140.39.123"
]
},
{
"host": "news.paypal.com",
"records": [
"192.243.228.1"
]
},
{
"host": "autodiscover.paypal.com",
"records": [
"52.96.79.120",
"52.96.79.200",
"52.96.163.40",
"52.96.79.248"
]
},
{
"host": "dl.paypal.com",
"records": [
"216.113.188.115"
]
},
{
"host": "connect.paypal.com",
"records": [
"151.101.65.21",
"151.101.129.21",
"151.101.1.21",
"151.101.193.21"
]
},
{
"host": "sandbox.paypal.com",
"records": [
"151.101.195.1",
"162.159.141.96",
"151.101.3.1"
]
},
{
"host": "training.paypal.com",
"records": [
"64.4.254.252"
]
},
{
"host": "c.paypal.com",
"records": [
"151.101.129.21",
"151.101.65.21",
"151.101.193.21",
"151.101.1.21"
]
},
{
"host": "business.paypal.com",
"records": [
"104.18.6.168",
"104.18.7.168"
]
},
{
"host": "service.paypal.com",
"records": [
"192.243.228.1"
]
},
{
"host": "login.paypal.com",
"records": []
},
{
"host": "t.paypal.com",
"records": [
"151.101.3.1",
"151.101.131.1",
"151.101.67.1",
"151.101.195.1"
]
},
{
"host": "status.paypal.com",
"records": [
"20.69.68.249"
]
},
{
"host": "shopping.paypal.com",
"records": [
"208.76.140.165"
]
},
{
"host": "newsletter.paypal.com",
"records": [
"192.243.228.1"
]
},
{
"host": "reports.paypal.com",
"records": [
"173.0.93.28"
]
},
{
"host": "forms.paypal.com",
"records": [
"216.113.190.190"
]
},
{
"host": "labs.paypal.com",
"records": [
"173.0.88.135"
]
},
{
"host": "p.paypal.com",
"records": [
"151.101.131.1",
"151.101.67.1",
"151.101.195.1",
"151.101.3.1"
]
},
{
"host": "transfer.paypal.com",
"records": [
"151.101.193.21",
"151.101.129.21",
"151.101.65.21",
"151.101.1.21"
]
},
{
"host": "xmpp.paypal.com",
"records": [
"173.224.160.144",
"173.224.160.141",
"185.97.80.137",
"185.97.80.136"
]
},
{
"host": "manager.paypal.com",
"records": [
"173.0.93.191"
]
},
{
"host": "developer.paypal.com",
"records": [
"151.101.1.21",
"151.101.193.21",
"151.101.129.21",
"151.101.65.21"
]
},
{
"host": "account.paypal.com",
"records": [
"192.243.228.1"
]
},
{
"host": "history.paypal.com",
"records": [
"151.101.129.21",
"151.101.193.21",
"151.101.65.21",
"151.101.1.21"
]
},
{
"host": "pics.paypal.com",
"records": [
"151.101.131.1",
"151.101.195.1",
"151.101.67.1",
"151.101.3.1"
]
},
{
"host": "registration.paypal.com",
"records": [
"173.0.93.135"
]
},
{
"host": "mcp.paypal.com",
"records": [
"104.18.7.170",
"104.18.6.170"
]
},
{
"host": "accounts.paypal.com",
"records": [
"173.0.93.28"
]
},
{
"host": "hotspot.paypal.com",
"records": [
"64.4.240.12"
]
},
{
"host": "bm.paypal.com",
"records": [
"130.211.16.153"
]
},
{
"host": "rms.paypal.com",
"records": [
"173.0.82.166"
]
},
{
"host": "cb.paypal.com",
"records": [
"173.0.88.142"
]
}
],
"count": 47,
"totalFound": 47,
"complete": true
}
}
Response fields
Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.
| Field | Type | Example | Description |
|---|---|---|---|
rootDomain | object | {…} | The domain that was scanned and its A records |
rootDomain.domain | string | paypal.com | The primary domain name for the scan |
rootDomain.records | array | ["151.101.3.1","151.101.195.1","162.159.141.96"] | IP addresses associated with the root domain |
subDomains | array[47] | List of discovered subdomains with their DNS records | |
subDomains.0.host | string | api.paypal.com | Full hostname of the discovered subdomain |
subDomains.0.records | array | ["66.211.168.123"] | IP addresses resolved for the subdomain |
count | number | 47 | Total number of subdomains discovered in this scan |
totalFound | number | 47 | Total number of subdomains found for the domain. Reads as "N+ (limit reached)" or "N+ (scan time limit reached)" when the scan stopped before exhausting the wordlist |
complete | boolean | true | False when the scan hit its time budget before finishing the wordlist, meaning more subdomains may exist |
Failure modes
Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.
| Status | What it means |
|---|---|
400 / 422 | The arguments did not validate. The message names the offending one. |
401 | The OAuth session is invalid or expired — reconnect the server. |
403 | Blocked by a key restriction or an IP allow-list. Never a bad identity. |
404 | This skill is not part of VerveKit. Check the catalog. |
429 | Out of credits, or a brief rate limit. The message tells them apart. |
A call costs 100 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.
Use cases
- Attack Surface Discovery
- Security engineers scan an organization's primary domain to find forgotten staging hosts and catalog exposed IP addresses before running vulnerability assessments.
- Asset Inventory Auditing
- When auditing corporate infrastructure, IT teams cross-reference discovered subdomain hostnames against internal DNS registers to catch untracked servers and shadow services.
- Bug Bounty Reconnaissance
- Penetration testers submit client domains to map newly issued certificates and gather resolved hostnames prior to testing web applications.
- Phishing Infrastructure Detection
- To catch spoofing campaigns, brand protection platforms query suspicious root domains to inspect resolving hostnames and flag active servers.
Other ways to use Subdomain Finder Skill
Set up Subdomain Finder Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.
Related
More in Domain Data: