Domains & DNS
Straight from the registries' RDAP servers (via IANA bootstrap) and live DNS. Works for every TLD with RDAP.
- cost
- Free tier 1 of 8 free, 7 with 3 free calls a day
- after that
- from $0.001 / call · card or USDC
- endpoints
- 8
No signup needed over MCP: 50 free calls a day, or 500 with a free key.
Domain availability 3 free / day
Registered or available, straight from the TLD registry.
- cost
- 3 free / day then $0.002 / call
- MCP tool
- domains__availability
- method
- GET
3 free calls a day, then $0.002 per call by card credit or USDC. Free key · Pay by card
GET https://fourzerotwo.si/v1/domains/availability
| Param | Type | Description |
|---|---|---|
| domain | string | Domain |
# free: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/domains/availability?domain=some-unregistered-name-402.com" # no key: returns 402 with the price, for x402 agents curl -i "https://fourzerotwo.si/v1/domains/availability?domain=some-unregistered-name-402.com"
by fourzerotwo
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Domain registration facts 3 free / day
Registrar, created, expiry, age, status codes, nameservers and DNSSEC.
- cost
- 3 free / day then $0.002 / call
- MCP tool
- domains__facts
- method
- GET
3 free calls a day, then $0.002 per call by card credit or USDC. Free key · Pay by card
GET https://fourzerotwo.si/v1/domains/facts
| Param | Type | Description |
|---|---|---|
| domain | string | Domain name (or URL) |
# free: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/domains/facts?domain=fourzerotwo.si" # no key: returns 402 with the price, for x402 agents curl -i "https://fourzerotwo.si/v1/domains/facts?domain=fourzerotwo.si"
by fourzerotwo
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DNS records 3 free / day
A, AAAA, MX, NS, TXT, CNAME and CAA records (or one type).
- cost
- 3 free / day then $0.001 / call
- MCP tool
- domains__dns
- method
- GET
3 free calls a day, then $0.001 per call by card credit or USDC. Free key · Pay by card
GET https://fourzerotwo.si/v1/domains/dns
| Param | Type | Description |
|---|---|---|
| domain | string | Domain name (or URL) |
| type? | string | A, AAAA, MX, NS, TXT, CNAME, CAA or ALL |
# free: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/domains/dns?domain=fourzerotwo.si" # no key: returns 402 with the price, for x402 agents curl -i "https://fourzerotwo.si/v1/domains/dns?domain=fourzerotwo.si"
by fourzerotwo
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IP owner 3 free / day
Network, organisation, range, country and abuse email for an IP, from the regional internet registry.
- cost
- 3 free / day then $0.002 / call
- MCP tool
- domains__ip-owner
- method
- GET
3 free calls a day, then $0.002 per call by card credit or USDC. Free key · Pay by card
GET https://fourzerotwo.si/v1/domains/ip-owner
| Param | Type | Description |
|---|---|---|
| ip | string | IPv4 or IPv6 address |
# free: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/domains/ip-owner?ip=8.8.8.8" # no key: returns 402 with the price, for x402 agents curl -i "https://fourzerotwo.si/v1/domains/ip-owner?ip=8.8.8.8"
by fourzerotwo
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DMCA agent 3 free / day
Published DMCA / abuse contact (email or form) for a major platform, host, CDN or registrar.
- cost
- 3 free / day then $0.002 / call
- MCP tool
- domains__dmca-agent
- method
- GET
3 free calls a day, then $0.002 per call by card credit or USDC. Free key · Pay by card
GET https://fourzerotwo.si/v1/domains/dmca-agent
| Param | Type | Description |
|---|---|---|
| domain | string | Platform domain or URL |
# free: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/domains/dmca-agent?domain=https%3A%2F%2Fwww.reddit.com%2Fr%2Ftest" # no key: returns 402 with the price, for x402 agents curl -i "https://fourzerotwo.si/v1/domains/dmca-agent?domain=https%3A%2F%2Fwww.reddit.com%2Fr%2Ftest"
by fourzerotwo
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Where to report a site 3 free / day
Everyone to send an abuse or takedown report to for a site: platform agent, hosting network (+ abuse email, CDN flag) and registrar.
- cost
- 3 free / day then $0.005 / call
- MCP tool
- domains__abuse-contacts
- method
- GET
3 free calls a day, then $0.005 per call by card credit or USDC. Free key · Pay by card
GET https://fourzerotwo.si/v1/domains/abuse-contacts
| Param | Type | Description |
|---|---|---|
| domain | string | Domain or URL |
# free: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/domains/abuse-contacts?domain=example.com" # no key: returns 402 with the price, for x402 agents curl -i "https://fourzerotwo.si/v1/domains/abuse-contacts?domain=example.com"
by fourzerotwo
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Email authentication check 3 free / day
MX, SPF and DMARC for a domain, the mail provider, issues found and a grade.
- cost
- 3 free / day then $0.003 / call
- MCP tool
- domains__email-auth
- method
- GET
3 free calls a day, then $0.003 per call by card credit or USDC. Free key · Pay by card
GET https://fourzerotwo.si/v1/domains/email-auth
| Param | Type | Description |
|---|---|---|
| domain | string | Domain |
# free: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/domains/email-auth?domain=gov.uk" # no key: returns 402 with the price, for x402 agents curl -i "https://fourzerotwo.si/v1/domains/email-auth?domain=gov.uk"
by fourzerotwo
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Domain name ideas Free
Rule-based domain candidates for a keyword: exact, stopword-free, hyphenated, prefixed and suffixed, across chosen TLDs, with a trademark flag.
- cost
- Free then $0.002 / call
- MCP tool
- domains__ideas
- method
- GET
Free up to 50 calls a day over MCP (500 with a free key), then $0.002 per call by card credit or USDC. Free key · Pay by card
GET https://fourzerotwo.si/v1/domains/ideas
| Param | Type | Description |
|---|---|---|
| keyword | string | Keyword or phrase |
| tlds? | string | Comma list of TLDs (default com,co.uk,io) |
| prefixes? | string | Comma list of prefixes |
| suffixes? | string | Comma list of suffixes |
| trademarks? | string | Comma list of brand names to flag |
# free: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/domains/ideas?keyword=how%20to%20unlock%20my%20phone" # no key: returns 402 with the price, for x402 agents curl -i "https://fourzerotwo.si/v1/domains/ideas?keyword=how%20to%20unlock%20my%20phone"
by fourzerotwo
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Registration data from registry RDAP services; DNS from live queries.