Hivex
Find unregistered .si domain names, and look up DNS records and WHOIS (RDAP) data for any domain. Free, no key.
Hosted MCP Server
npx add-mcp 'https://hivex.si/mcp'Installs into Claude Code, Codex, Cursor and more
Documentation
Hivex APIFree · No key · JSON
Domain signals, machine-readable.
A free JSON API for scripts, naming tools and AI agents. Check whether a domain is free to register, search short.si names that still are, and read the size of the index. No key and no sign-up.
Base URL
Key
None. No account, no cost.
CORS
Open to every origin.
Limits
Per address and minute: 120 searches (20 past page 5 of a list), 30 live checks, 300 other reads, 240 MCP calls. Past that the answer is 429 with Retry-After: 60.
Spec
OpenAPI 3.1 at /openapi.json
01
Check a domain
GET/api/v1/check?domain={domain}
Is a domain free to register right now? Pass a full domain (.com,.ai,.dev,.si and most other extensions), or a bare word, which is checked as.si. Each answer comes from DNS over HTTPS and the registry’s RDAP, asked live, then kept for 10 minutes per domain.
available
Free to register: no DNS delegation and no record at the registry. register_at lists registrars that sell it.
registered
Someone holds it. registered_at is the registration date when the registry shares it.
unknown
No clear answer, for example when an extension’s registry has no public lookup. Treat it as unconfirmed, not as free.
Request
curl "https://hivex.si/api/v1/check?domain=mindex.si"
Response
{
"domain": "mindex.si",
"status": "registered",
"registered_at": "2026-09-30T14:21:19Z",
"checked_at": "2026-10-05T19:30:57.342Z",
"method": "DNS over HTTPS + the registry's RDAP",
"register_at": [],
"more": "https://hivex.si/check?d=mindex.si"
}
02
Search free.si names
GET/api/v1/names
Searches and ranks the short.si names that are free to register, strongest first. Answers come from the last index refresh (index_built_at in the stats), not a live check, so confirm a name with /api/v1/check before you rely on it.
q
Text the name contains: letters, digits and hyphens, up to 30.
prefix
Text the name starts with.
min_len, max_len
Letters before.si, 1 to 63.
min_score
Lowest ranking score, 0 to 100.
status
free: the registry confirmed it. likely: no DNS delegation, not confirmed yet. all (default): both. Each result says which, as free or likely_free.
free, taken
An extension (com, ai, io, net, co, app, dev, org) where the same word looks unregistered, or is registered.
sort
rank (default), or new for the newest finds first.
limit, offset
Page size 1 to 100 (default 20). Pass next_offset and the cursor from a response to get the next page: every name can be reached, 20 pages ahead at a time. Without a cursor an offset goes up to page 20; a deeper one returns the furthest page it may (capped: true).
Also category, tier, kind, max_age and factors: see the OpenAPI spec.
Request
curl "https://hivex.si/api/v1/names?max_len=5&min_score=70&status=free&limit=1"
Response
{
"ranking": "hivex-domain-ranking-v4",
"sort": "rank",
"offset": 0,
"count": 1,
"has_more": true,
"next_offset": 1,
"note": "status free: the registry confirmed it; likely_free: no DNS delegation, not confirmed yet (filter with status=free|likely). Confirm a name with /api/v1/check before you rely on it.",
"results": [
{
"domain": "botsx.si",
"status": "free",
"score": 79.7,
"tier": "Very Good",
"category": "Agents / Automation",
"estimated": false,
"chars": 5,
"style": "Prefix / suffix",
"parts": ["bots", "x"],
"themes": ["agents"],
"registered_on": ["com", "ai", "co"],
"free_on": ["io", "net", "app", "dev", "org"],
"brand_risk": false,
"found_at": "2026-10-02T13:41:05.965Z",
"checked_at": "2026-10-02T13:41:05.965Z",
"url": "https://hivex.si/domain/botsx.si"
}
]
}
03
Index stats
GET/api/v1/stats
The size and freshness of the.si index: names free to register now, names found and names registered by others in the last 7 days, and when the index was built.
Request
curl "https://hivex.si/api/v1/stats"
Response
{
"si_names_available": 67384,
"found_last_7_days": 67384,
"registered_by_others_last_7_days": 3513,
"index_built_at": "2026-10-05T18:58:14.224Z",
"browse": "https://hivex.si/names"
}
04
Premium names for sale
GET/api/v1/premium
Every premium domain for sale on Hivex, on any extension, with its tagline, price and the page to buy it or make an offer. price_usd is null when a name is open to offers. Sales run through AtomPay by Atom.com.
Request
curl "https://hivex.si/api/v1/premium"
Response, trimmed to one domain
{
"count": 53,
"payment": "AtomPay (Atom.com): Atom holds the payment and pays the seller once the domain has transferred.",
"domains": [
{
"domain": "mindex.si",
"price_usd": null,
"min_offer_usd": null,
"buy": "offer_only",
"tagline": "Everything your mind knows, indexed.",
"summary": "Mind plus index: a six-letter name for products that map, measure or search what minds know.",
"good_for": ["AI knowledge search and retrieval", "Mental wellbeing and cognitive tech", "AI evaluation and benchmarking"],
"also_registered_on": [],
"url": "https://hivex.si/domain/mindex.si"
}
]
}
05
DNS records of any domain
GET/api/v1/tools/dns?name={name}&type={type}
The DNS records of any domain or hostname on any extension, asked live of Cloudflare's resolver over HTTPS and kept for the records' TTL (30 seconds to 5 minutes). type is one of A, AAAA, CNAME, MX, NS, TXT, CAA, SOA, PTR, DS, DNSKEY, HTTPS or SRV (default A); pass an IP address for its reverse DNS (PTR). Each answer links to the same lookup explained in plain words on the free tools.
Request
curl "https://hivex.si/api/v1/tools/dns?name=hivex.si&type=MX"
Response
{
"ok": true,
"name": "hivex.si",
"type": "MX",
"status": "NOERROR",
"dnssec_validated": false,
"records": [
{
"name": "hivex.si",
"type": "MX",
"ttl": 300,
"data": "28 route3.mx.cloudflare.net"
},
{
"name": "hivex.si",
"type": "MX",
"ttl": 300,
"data": "76 route2.mx.cloudflare.net"
},
{
"name": "hivex.si",
"type": "MX",
"ttl": 300,
"data": "89 route1.mx.cloudflare.net"
}
],
"resolver": "Cloudflare 1.1.1.1 (DNS over HTTPS)",
"checked_at": "2026-10-10T18:45:05.067Z",
"url": "https://hivex.si/tools/mx-lookup/hivex.si"
}
06
Registration record (WHOIS)
GET/api/v1/tools/whois?domain={domain}
A domain's registration record, read live from its registry's RDAP, the successor of WHOIS: whether it is registered, the registrar and its IANA ID and abuse contact, the created, expiry and last-changed dates, the status codes and the name servers. At most an organisation name for the holder, never a person's details. Cached an hour per domain (six for.si) and limited like the live checker.
Request
curl "https://hivex.si/api/v1/tools/whois?domain=hivex.si"
07
MCP server
The same index as tools an AI assistant can call: find_names searches the free.si names by a word, length or score, and check_name answers for one name (free, likely free, for sale on Hivex, or registered), dns_lookup reads the DNS records of any domain, and whois_lookup its registration record. Every answer links to its page on hivex.si. Remote MCP over Streamable HTTP, no account and no key; it speaks MCP 2026-07-28 and the earlier revisions that open with initialize.
Claude
Settings, Connectors, Add custom connector. Paste the URL above; no authentication.
ChatGPT
Settings, Apps, Advanced settings: turn on Developer mode, then Create app with the URL above and No authentication.
Other clients
Any MCP client that supports remote servers: add the URL as a Streamable HTTP server. Listed in the official MCP Registry as si.hivex/names.
08
Good to know
Caching
Checks are kept at the edge for 10 minutes per domain, everything else for 5 minutes. Cache on your side too, and pace bulk jobs.
Errors
JSON with an error message: 400 for a missing or invalid parameter, 429 past a limit (wait as long as Retry-After says), 503 from /api/v1/names while the index is not ready.
Freshness
Availability changes all the time. Confirm at the registrar before you pay.
AI assistants
/llms.txt describes the site and this API in Markdown.