# Reverse DNS Change Watch via NextDNS

> Reverse DNS Change Watch via NextDNS is a paid API for AI agents from ip.intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-11).

Monitors the reverse DNS (PTR) record of an IP address via NextDNS, detecting and reporting any changes since the last check.

## Facts

- Endpoint: GET https://ip.intel.rallylive.ca/watch/ip/ptr/via/nextdns?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/reverse-dns-change-watch-via-nextdns-5fd134d2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7-ouJRKqzGDwn_tYgDSWw

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 reverse-dns-change-watch-via-nextdns-5fd134d2
```

Example prompt: Keep an eye on the reverse DNS record for 104.21.45.67 using NextDNS — let me know if the PTR record has changed since the last time you checked.

## When to prefer this

Use this endpoint when you need to detect changes in reverse DNS (PTR records) for specific IP addresses over time, especially via NextDNS as the resolver. Prefer this over a plain PTR lookup when you want change detection with before/after diffs rather than just the current value. Ideal for scheduled monitoring pipelines, security alerting, or ISP reassignment tracking where knowing WHAT changed matters as much as the current state.

## Known failure modes

- IP address not provided or malformed — returns error
- NextDNS resolution failure or timeout — may return error or empty PTR
- No previous check exists for this IP yet — 'changed' will be false or indeterminate on first call
- IP has no PTR record — returns empty or NXDOMAIN response
- Payment not processed (x402) — request blocked before execution

## How this service works

Change watch for reverse dns via nextdns: runs the check, compares it with the result from your previous call for the same ip (kept 90 days) and returns the current answer, changed true/false, the fields that changed with before/after values, and when it was last seen. Schedule it to be alerted when this changes. $0.02 per check.

## Output

Returns the current PTR (reverse DNS) record for the IP, a boolean 'changed' flag indicating whether it differs from the previous check, a list of fields that changed with before/after values, and the timestamp of when the record was last seen. Previous results are retained for 90 days for comparison.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/reverse-dns-change-watch-via-nextdns-5fd134d2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ip.intel.rallylive.ca](https://www.zero.xyz/host/ip.intel.rallylive.ca/llms.txt)