# Reverse DNS Lookup Change Watch

> Reverse DNS Lookup Change Watch is a paid API for AI agents from intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Monitors reverse DNS (PTR) records for a given IP address and alerts when they change, comparing current results against a stored baseline from up to 90 days ago.

## Facts

- Endpoint: GET https://intel.rallylive.ca/watch/dns/reverse
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/reverse-dns-lookup-change-watch-2d1d44f1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CQETyJHZYJiwKMWETW8Us

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-lookup-change-watch-2d1d44f1
```

Example prompt: Keep an eye on the reverse DNS for 203.0.113.42 and let me know if the PTR record has changed since the last time you checked.

## When to prefer this

Choose this endpoint when you need to detect changes in reverse DNS (PTR) records for a specific IP address over time, rather than performing a one-off lookup. It is ideal for scheduled agent workflows that need to be notified of infrastructure changes, security anomalies, or ISP reassignments without maintaining your own state — the service stores the baseline for 90 days. Prefer this over a raw reverse DNS lookup when change detection and diffing are the primary goal.

## Known failure modes

- IP address not provided or malformed — returns validation error
- No previous baseline exists yet (first call) — returns current result with changed=false or no diff
- IP has no PTR record — returns empty or NXDOMAIN result
- Baseline older than 90 days has been purged — no comparison available
- Network error reaching DNS servers — returns upstream failure

## How this service works

Change watch for reverse dns lookup: runs the check and compares it with the result from your previous call for the same ip (kept 90 days), returning the current answer, changed true/false, exactly which fields changed with before/after values, and when it was last seen. Call it on a schedule to be told when reverse dns changes. $0.01 per check.

## Output

Returns the current reverse DNS (PTR) lookup result for the IP, a boolean indicating whether it has changed since the last call, a detailed diff of exactly which fields changed with before and after values, and a timestamp of when the record was last seen. The baseline is retained for up to 90 days.

## 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-lookup-change-watch-2d1d44f1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from intel.rallylive.ca](https://www.zero.xyz/host/intel.rallylive.ca/llms.txt)