# DNS MX Change Watch via DNS.SB

> DNS MX Change Watch via DNS.SB is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Monitors MX DNS records for a domain using DNS.SB and returns the current result plus a change diff compared to the previous check (stored 90 days).

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/watch/dns/mx/via/dnssb?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dns-mx-change-watch-via-dns-sb-49a49f5b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Yuv7JT-9Bw9Lv58preCKH

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 dns-mx-change-watch-via-dns-sb-49a49f5b
```

Example prompt: Keep an eye on the MX records for example.com using DNS.SB and let me know if anything changes — I want to see what fields shifted and what the values were before and after.

## When to prefer this

Use this endpoint when you need to detect changes in MX (mail exchanger) records specifically, using DNS.SB as the resolver, and want built-in diffing against a stored previous result rather than maintaining your own snapshot state. Ideal for scheduled monitoring workflows where you want change alerts without managing history yourself.

## Known failure modes

- Domain not found or NXDOMAIN — returns empty record set with no change data
- DNS.SB resolver unavailable — query fails with upstream error
- No prior result stored (first call) — 'changed' is false or undefined, no diff available
- Invalid domain format in query — request rejected
- Rate limiting or payment failure — call blocked

## How this service works

Change watch for dns mx via dnssb: runs the check, compares it with the result from your previous call for the same domain (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 MX record answer from DNS.SB, a boolean 'changed' flag, a list of fields that changed with before and after values, and a timestamp of when the record was last seen. Previous result is stored for up to 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/dns-mx-change-watch-via-dns-sb-49a49f5b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from dns.intel.rallylive.ca](https://www.zero.xyz/host/dns.intel.rallylive.ca/llms.txt)