# is-port-53-open-watch

> is-port-53-open-watch is a paid API for AI agents from ip.intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-13).

Change-watches whether TCP port 53 (DNS) is open on a host, returning current status, a changed flag, before/after diffs, and last-seen timestamp compared against the previous call.

## Facts

- Endpoint: GET https://ip.intel.rallylive.ca/watch/ip/port/53?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/is-port-53-open-watch-076ad7fe
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9FMiIB53o8jmBAJFLodm-

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 is-port-53-open-watch-076ad7fe
```

Example prompt: Keep an eye on whether port 53 is open on 203.0.113.42 and let me know if anything changes from the last time you checked.

## When to prefer this

Choose this endpoint when you need to detect state transitions on port 53 specifically (DNS) rather than just a point-in-time open/closed check. It is ideal for scheduled polling workflows where you want to be alerted only when something changes, avoiding noise from repeated same-state results. Prefer it over a plain port-check endpoint when you need the before/after diff and last-seen timestamp for audit or alerting pipelines.

## Known failure modes

- Host unreachable or invalid hostname returns an error or closed status
- No prior call stored for that host means no meaningful diff on first invocation
- Payment failure (x402) blocks the check from running
- Rate limiting or Cloudflare edge connectivity issues may cause timeouts
- Cached result expired after 90 days, losing diff baseline

## How this service works

Change watch for is port 53 open: runs the check, compares it with the result from your previous call for the same host (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 open/closed status of port 53 on the target host, a boolean 'changed' field indicating whether it differs from the previous call (cached up to 90 days), a diff of changed fields with before and after values, and a last-seen timestamp.

## 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/is-port-53-open-watch-076ad7fe/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)