# 2s WHOIS Domain Watcher

> 2s WHOIS Domain Watcher is a paid API for AI agents from 2s.io, paid per call via x402, $0.125/call, status unknown (last checked 2026-09-14).

Sets up a persistent watcher that monitors a domain's WHOIS record and POSTs a signed callback whenever changes are detected

## Facts

- Endpoint: POST https://2s.io/api/watchers/whois
- Price: $0.125/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/2s-whois-domain-watcher-81af7133
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oh4Av3kScpP2ZAMDJ634a

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability 2s-whois-domain-watcher-81af7133 -d '<json body>'
```

Example prompt: Set up a WHOIS change watcher on competitor.com for the next 30 days — send callbacks to https://hooks.myapp.com/whois-alert and stop after 5 changes.

## When to prefer this

Choose this endpoint when you need continuous, asynchronous monitoring of a domain's WHOIS record over a defined window rather than a one-shot lookup. It is ideal for brand protection, competitive intelligence, domain acquisition targeting, and compliance use cases where you want to be notified of ownership, registrar, nameserver, or expiry changes without polling manually. Prefer it over a simple WHOIS lookup endpoint when the goal is ongoing surveillance rather than a single snapshot.

## Known failure modes

- Invalid or unresolvable domain returns a 422 validation error
- callbackUrl that is unreachable or returns non-2xx causes delivery retries then potential watcher suspension
- expiresInSeconds exceeding 7776000 (90 days) returns a validation error
- maxFires outside 1–1000 range rejected
- Payment failure via x402 prevents watcher creation
- Malformed callback signature verification on the receiver side is a client-side misconfiguration, not an API error

## How this service works

The (most) everything API: 575+ pay-per-call endpoints for AI agents — ground-truth data, a full AI gateway, and agent infrastructure (storage, queues, watchers). USDC via x402, no signup, no API keys, and upto billing: pay actual usage, not the quote.

## Output

Returns a watcher object with a unique watcher ID and confirmation that monitoring is active. Subsequently, whenever the target domain's WHOIS record changes, a signed HTTP POST is sent to the provided callbackUrl containing the diff, the echoed custom payload, and an X-2s-Signature header for verification. The watcher deactivates after maxFires events or after the expiresInSeconds window elapses.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "label": {
   "type": "string",
   "maxLength": 64,
   "description": "Optional free-text tag."
  },
  "domain": {
   "type": "string",
   "maxLength": 255,
   "minLength": 3,
   "description": "Domain to monitor, e.g. example.com."
  },
  "payload": {
   "type": "object",
   "description": "Arbitrary JSON echoed back in every callback.",
   "additionalProperties": {}
  },
  "maxFires": {
   "type": "integer",
   "maximum": 1000,
   "minimum": 1,
   "description": "Stop after this many changes (default 10)."
  },
  "callbackUrl": {
   "type": "string",
   "maxLength": 2048,
   "description": "Signed event POSTed here (verify X-2s-Signature). Any http(s) URL."
  },
  "expiresInSeconds": {
   "type": "integer",
   "maximum": 7776000,
   "minimum": 60,
   "description": "Active window in seconds (default 30d, max 90d)."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/2s-whois-domain-watcher-81af7133/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 2s.io](https://www.zero.xyz/host/2s.io/llms.txt)