Overview
Who else is on this IP, and since when. Reverse IP, DNS history and network context from one REST API and an MCP server.
IP Almanac answers questions about public IPs and domains from DNS answers we record ourselves, plus the IP ranges providers publish and an imported ASN mapping. Look up an IP for the domains seen on it, its PTR name and the network that routes it. Look up a domain for everywhere it has pointed and the networks it moved through. Every DNS answer is dated: when we first observed it, when we last confirmed it, and when it ended.
Private preview
To ask for an invitation, email support@ipalmanac.com. New workspaces start on the Free plan; Starter and Pro are not on sale yet.
curl https://api.ipalmanac.com/v1/ip/54.10.20.30 \
-H "Authorization: Bearer $IPALMANAC_API_KEY"{
"ip": "54.10.20.30",
"asn": { "asn": 64500, "descr": "EXAMPLE-CLOUD - Example Cloud, Inc.", "country": "US", "source": "IPtoASN" },
"is_datacenter": true,
"is_cdn": null,
"provider": "examplecloud",
"prefix": "54.10.20.0/24",
"ptr": { "names": ["host-54-10-20-30.examplecloud.example"], "status": "positive" },
"domains": {
"current_count": 2,
"sample": ["alpha.example", "gamma.example"],
"first_observed": "2026-10-01T03:10:00+00:00",
"last_confirmed": "2026-10-06T01:40:00+00:00"
},
"release": { "id": "20261006T020000Z", "built_at": "2026-10-06T02:00:00+00:00" }
}Quickstart
Create a key and make your first lookup.
API reference
Each REST operation, with its parameters, responses and errors.
Read a response
What null, empty, stale and the dates mean.
MCP and AI agents
Give an agent the same lookups as tools.
What you can ask
| Question | Operation |
|---|---|
| What is this IP: its network, cloud, hosting or CDN range, PTR name, and how many domains are on it? | GET /v1/ip/{ip} |
| Which domains were seen on this IP, and when? | GET /v1/ip/{ip}/domains |
| What has this domain resolved to over time? | GET /v1/domain/{domain}/history |
| Which networks has this domain moved through? | GET /v1/domain/{domain}/hosting |
| What does this network (AS number) route, and what kind of network is it? | GET /v1/asn/{asn} |
The same five lookups are MCP tools for AI agents.
Basics
- Base URL:
https://api.ipalmanac.com. HTTPS only, and no trailing slash on paths. - Authentication: an API key in the
Authorization: Bearerheader. See Authentication. - Format: every lookup is a
GETthat returns JSON. Times are UTC, in ISO 8601. - Limits: a monthly quota and a per-minute rate per workspace. See Rate limits and quotas.
- Spec: the OpenAPI document is at
https://api.ipalmanac.com/v1/openapi.json.
What it is not
We report what we observe, what operators publish, and a classification of the network that routes an IP: ours
where we have one and ipverse's where we don't, labeled with its source. We don't offer geolocation, abuse or reputation scores, WHOIS or company ownership, and we don't
guess: unknown stays null. Data and coverage says where the data is strong and where it is
thin.