RDAP API is a REST API that replaces WHOIS with structured JSON lookups for domains, IP networks, ASNs, nameservers, and entities. It queries RDAP (Registration Data Access Protocol) — the official WHOIS successor defined in RFCs 7480–7484 — and normalizes responses into a flat, consistent format across 1,200+ TLDs and all five RIRs.
No more parsing unstructured WHOIS text or nested vcardArray. One API call, one JSON shape, every registry.
curl -H "Authorization: Bearer YOUR_TOKEN" \
https://rdapapi.io/api/v1/domain/google.comReturns registrar, registration/expiration dates, nameservers, DNSSEC status, and contact data — all in a single normalized JSON response.
| Endpoint | Returns |
|---|---|
GET /api/v1/domain/{domain} |
Registrar, dates, nameservers, EPP status codes, DNSSEC, contacts |
POST /api/v1/domains/bulk |
Up to 10 domains in one pooled request (Pro and Business) |
GET /api/v1/ip/{ip} |
Network range, holder, country, abuse contacts, geofeed URL |
GET /api/v1/asn/{asn} |
Autonomous system holder, country, registration dates |
GET /api/v1/nameserver/{host} |
Host record: addresses, status, sponsoring registrar |
GET /api/v1/entity/{handle} |
Organization or contact by RIR handle |
GET /api/v1/tlds |
Every supported TLD, its server, and per-field availability — never billed |
- Normalized JSON — consistent fields across all supported TLDs and RIRs, no WHOIS parsing
- WHOIS fallback — ccTLDs with no RDAP server are read over WHOIS and returned in the same shape, marked
source: whois - Registrar follow-through —
?follow=truemerges thin registry + registrar RDAP data in one call - 1,200+ TLDs supported — gTLDs, ccTLDs, and new TLDs, including registries missing from IANA's bootstrap file
- Bulk domain lookups — up to 10 domains per request with concurrent upstream fetches
- MCP server — the same lookups as tools for AI agents at rdapapi.io/mcp
- Fast & cached — sub-50ms cached responses, no upstream rate limit issues
- Simple Bearer auth — one API key, usage dashboard, predictable pricing
- Domain monitoring and expiration tracking
- Registrar and WHOIS data enrichment
- Brand protection and trademark monitoring
- Security research and threat intelligence
- Network and ASN attribution
- Domain portfolio management
All clients cover domain, bulk, IP, ASN, nameserver, and entity lookups.
| Language | Package | Install | Source |
|---|---|---|---|
| Python | rdapapi | pip install rdapapi |
python-sdk |
| Node.js | rdapapi | npm install rdapapi |
node-sdk |
| PHP | rdapapi/rdapapi-php | composer require rdapapi/rdapapi-php |
rdapapi-php |
| Go | rdapapi-go | go get github.com/rdapapi/rdapapi-go |
rdapapi-go |
| Java | rdapapi-java | Maven Central | java-sdk |
- API Documentation — interactive OpenAPI explorer with live requests
- MCP Server — RDAP lookups as tools for AI agents
- TLD Directory — browse all 1,200+ supported TLDs and their RDAP servers
- RDAP Coverage Stats — how much of the DNS answers over RDAP, backend concentration, certificate health
- WHOIS Sunset Tracker — where each registry stands in the ICANN WHOIS-to-RDAP transition
- Blog — RDAP protocol guides, migration walkthroughs, and comparisons
- Pricing — 7-day free trial, plans from $9/mo
- Free Domain Lookup — try RDAP lookups without signing up