@cyanheads/whois-mcp-server
Look up domain registration, check availability, fetch DNS records, and resolve IPs and ASNs via RDAP and DNS-over-HTTPS via MCP. STDIO or Streamable HTTP.
6 Tools
[](./CHANGELOG.md) [](./LICENSE) [](https://github.com/users/cyanheads/packages/container/package/whois-mcp-server) [](https://modelcontextprotocol.io/) [](https://www.npmjs.com/package/@cyanheads/whois-mcp-server) [](https://www.typescriptlang.org/) [](https://bun.sh/)
[](https://github.com/cyanheads/whois-mcp-server/releases/latest/download/whois-mcp-server.mcpb) [](https://cursor.com/en/install-mcp?name=whois-mcp-server&config=eyJjb21tYW5kIjoibnB4IiwiYXJncyI6WyIteSIsIkBjeWFuaGVhZHMvd2hvaXMtbWNwLXNlcnZlciJdfQ==) [](https://vscode.dev/redirect?url=vscode:mcp/install?%7B%22name%22%3A%22whois-mcp-server%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22-y%22%2C%22%40cyanheads%2Fwhois-mcp-server%22%5D%7D)
[](https://www.npmjs.com/package/@cyanheads/mcp-ts-core)
---
## Overview
Domain and network intelligence via RDAP and DNS-over-HTTPS. Look up domain registrations, check availability, fetch DNS records, and resolve IPs and ASNs to their registries — all via public, keyless data sources. Runs as a stdio process or a local Streamable HTTP server.
### Tools
| Tool | Description |
|:-----|:------------|
| `whois_lookup_domain` | Full domain registration record — registrar, created/expiry dates, nameservers, EPP status, DNSSEC, registrant org |
| `whois_check_availability` | Check whether a domain is registered or available for registration |
| `whois_get_dns` | DNS records for any hostname via DNS-over-HTTPS (A, AAAA, MX, TXT, NS, CNAME, SOA, CAA, PTR) |
| `whois_lookup_ip` | IP or CIDR netblock, org, country, abuse contact, and reverse DNS via RIR RDAP |
| `whois_lookup_asn` | Resolve an ASN to its org name, country, and RIR source |
| `whois_get_dossier` | One-call domain triage — registration + DNS in parallel, normalized into a single record with factual signals |
---
## Capability reference
### `whois_lookup_domain` tool
- RDAP-first via IANA auto-bootstrap — automatically selects the correct registry RDAP server per TLD
- Returns registrar, creation/expiry dates, nameservers, EPP status codes, and DNSSEC delegation flag
- Surfaces `registrant_redacted: true` when privacy redaction is in effect (standard post-GDPR for gTLDs)
- Throws `rdap_no_coverage` when the TLD has no RDAP server in the IANA bootstrap — use `whois_check_availability` instead
- Throws `domain_not_found` on an RDAP 404 (domain not registered) — use `whois_check_availability` to confirm
---
### `whois_check_availability` tool
- RDAP 404 response maps to `available: true`
- Registered domains return `available: false` with `registrar` and `expiry_date`
- `available: null` with `rdap_coverage: false` when the TLD has no RDAP coverage — availability cannot be determined
- Thin response optimized for bulk name sweeps — no extra fields
---
### `whois_get_dns` tool
- Supports A, AAAA, MX, TXT, NS, CNAME, SOA, CAA, PTR; multiple types fetched in parallel; defaults to A, AAAA, MX, TXT, NS when `types` is omitted
- Cloudflare primary, NextDNS fallback per type (CAA always uses NextDNS — Cloudflare returns raw hex wire format for it)
- Returns records with TTLs and the resolving `source` (`cloudflare` or `nextdns`)
- `nxdomain: true` in the result (not an error) when the domain doesn't exist in DNS
---
### `whois_lookup_ip` tool
- Accepts an IPv4/IPv6 address or CIDR block; auto-routes to the correct RIR (ARIN, RIPE, APNIC, LACNIC, AFRINIC) via IANA IP bootstrap
- Returns netblock CIDR, org name, country, abuse contact email
- Fetches PTR (reverse DNS) via DoH as a best-effort step — `ptr: null` on failure, not an error
- Throws `private_range` for RFC 1918, loopback, and link-local addresses — no RIR RDAP record exists for them
- Throws `ip_not_found` on an RIR RDAP 404
---
### `whois_lookup_asn` tool
- Accepts `AS15169` or bare integer `15169` format
- Routes to the correct RIR RDAP endpoint via IANA ASN bootstrap
- Returns `name`, `org_name`, `country`, `rir`, `start_autnum`, `end_autnum`
- Throws `asn_not_found` on an RIR RDAP 404
---
### `whois_get_dossier` tool
- Runs RDAP domain lookup and DoH (A, MX, NS, TXT) in parallel via `Promise.allSettled`
- Inferred signals: `age_days`, `privacy_redacted`, `registrar`, `ns_provider` (from NS records), `mx_provider` (from MX records)
- No synthesized risk scores — factual signals only; the agent decides the verdict
- Partial results surfaced when one leg fails (`rdap_source_error` / `dns_source_error` on the failed leg)
- Throws `both_legs_failed` only when both RDAP and DNS fail; individual leg failures are data, not errors
---
## Features
Built on [`@cyanheads/mcp-ts-core`](https://github.com/cyanheads/mcp-ts-core): stdio and Streamable HTTP transports, pluggable auth (`none` / `jwt` / `oauth`), swappable storage (`in-memory`, `filesystem`, `Supabase`, `Cloudflare KV/R2/D1`), structured logging with optional OpenTelemetry tracing.
RDAP / DNS-specific:
- RDAP over HTTPS — no port-43 TCP dependency
- IANA bootstrap auto-selection — correct registry RDAP server picked per TLD, RIR, or ASN range; bootstrap JSON cached in-memory for 24h
- DNS-over-HTTPS via Cloudflare and NextDNS — dual-provider with per-type routing (NextDNS for CAA; Cloudflare for all others) and automatic fallback
- No API keys required — all sources (IANA, registry RDAP endpoints, RIR RDAP, Cloudflare DoH, NextDNS DoH) are public and keyless
Agent-friendly output:
- Coverage signaled two ways — `rdap_coverage: false` returned as data by `whois_check_availability` and `whois_get_dossier`, while `whois_lookup_domain` throws `rdap_no_coverage` for the same case
- Privacy redaction surfaced as a field — `registrant_redacted: true` rather than silently absent contact data
- Partial failure model — `whois_get_dossier` marks individual legs with a `source_error` field and continues; only both-legs-fail escalates to an error
- Factual signals, not scores — `age_days`, `privacy_redacted`, `ns_provider`, `mx_provider` are real data, not synthesized risk scores
---
## Getting started
No API keys or accounts required. Add the following to your MCP client configuration file.
```json
{
"mcpServers": {
"whois-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/whois-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
```
Or with npx (no Bun required):
```json
{
"mcpServers": {
"whois-mcp-server": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@cyanheads/whois-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
```
Or with Docker:
```json
{
"mcpServers": {
"whois-mcp-server": {
"type": "stdio",
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MCP_TRANSPORT_TYPE=stdio",
"ghcr.io/cyanheads/whois-mcp-server:latest"
]
}
}
}
```
For Streamable HTTP, set the transport and start the server:
```sh
MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp
```
### Prerequisites
- [Bun v1.3.0](https://bun.sh/) or higher (or Node.js v24+).
- No API keys required — all data sources are public.
### Installation
1. **Clone the repository:**
```sh
git clone https://github.com/cyanheads/whois-mcp-server.git
```
2. **Navigate into the directory:**
```sh
cd whois-mcp-server
```
3. **Install dependencies:**
```sh
bun install
```
4. **Configure environment:**
```sh
cp .env.example .env
# All vars are optional — defaults work for most use cases
```
---
## Configuration
| Variable | Description | Default |
|:---------|:------------|:--------|
| `RDAP_TIMEOUT_MS` | HTTP timeout for RDAP requests in milliseconds. | `5000` |
| `DOH_TIMEOUT_MS` | HTTP timeout for DNS-over-HTTPS requests in milliseconds. | `3000` |
| `RDAP_MAX_RETRIES` | Max retry attempts on transient RDAP failures. | `2` |
| `DOH_MAX_RETRIES` | Max retry attempts on transient DoH failures. | `2` |
| `MCP_TRANSPORT_TYPE` | Transport: `stdio` or `http`. | `stdio` |
| `MCP_HTTP_PORT` | Port for HTTP server. | `3010` |
| `MCP_AUTH_MODE` | Auth mode: `none`, `jwt`, or `oauth`. | `none` |
| `MCP_LOG_LEVEL` | Log level (RFC 5424). | `info` |
| `OTEL_ENABLED` | Enable [OpenTelemetry instrumentation](https://github.com/cyanheads/mcp-ts-core/tree/main/docs/telemetry). | `false` |
See [`.env.example`](./.env.example) for the full list of optional overrides.
---
## Running the server
### Local development
- **Build and run:**
```sh
bun run rebuild
bun run start:stdio
# or
bun run start:http
```
- **Run checks and tests:**
```sh
bun run devcheck # Lint, format, typecheck, security
bun run test # Vitest test suite
bun run lint:mcp # Validate MCP definitions against spec
```
### Docker
```sh
docker build -t whois-mcp-server .
docker run --rm -p 3010:3010 whois-mcp-server
```
The Dockerfile defaults to HTTP transport, stateless session mode, and logs to `/var/log/whois-mcp-server`. OpenTelemetry peer dependencies are installed by default — build with `--build-arg OTEL_ENABLED=false` to omit them.
---
## Project structure
| Path | Purpose |
|:-----|:--------|
| `src/index.ts` | Entry point — starts the app. |
| `src/app.ts` | `createApp()` options — registers tools, inits services, declares the session mode. |
| `src/config/` | Server-specific environment variable parsing and validation (Zod). |
| `src/services/rdap/` | RDAP client — IANA bootstrap cache, domain/IP/ASN lookup, retry. |
| `src/services/doh/` | DNS-over-HTTPS client — Cloudflare primary, NextDNS fallback. |
| `src/mcp-server/tools/` | Tool definitions (`*.tool.ts`). |
| `tests/` | Vitest tests mirroring `src/`. |
| `docs/` | Design and API reference documents. |
---
## Development guide
See [`CLAUDE.md`](./CLAUDE.md) for development guidelines and architectural rules. The short version:
- Handlers throw, framework catches — no `try/catch` in tool logic
- Use `ctx.log` for request-scoped logging
- Register new tools via `src/app.ts`'s `tools` array
- Wrap external API calls: validate raw → normalize to domain type → return output schema; never fabricate missing fields
---
## Contributing
Issues are welcome. Run checks and tests before submitting:
```sh
bun run devcheck
bun run test
```
---
## License
Apache-2.0 — see [LICENSE](LICENSE) for details.