# DKIM HS1 Selector Change Watch

> DKIM HS1 Selector Change Watch is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-20).

Monitors the DKIM selector 'hs1' DNS record for a given domain and returns whether it has changed since the last check, including before/after field values.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/watch/dns/dkim/hs1?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dkim-hs1-selector-change-watch-83d39669
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lao4tiNwPn9mUfcv3zCnM

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 dkim-hs1-selector-change-watch-83d39669
```

Example prompt: Check if the DKIM hs1 selector for example.com has changed since the last time you looked, and tell me what fields are different now.

## When to prefer this

Use this endpoint when you need to detect changes to a DKIM hs1 selector specifically, rather than just reading its current value. It is ideal for scheduled monitoring workflows where you want an alert-style changed flag and field-level diff rather than raw DNS data. Prefer this over a plain DNS lookup when you need historical comparison built-in without managing state yourself.

## Known failure modes

- Domain has no hs1 DKIM selector record — returns current empty/null result with no previous data to compare
- First-ever call for a domain — no prior state exists so 'changed' cannot be determined and baseline is stored
- DNS lookup failure due to upstream resolver issues — may return error or timeout
- Domain name not provided or malformed — request fails validation
- Cached result older than 90 days — previous state has expired and comparison resets

## How this service works

Change watch for dkim selector hs1: 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 DKIM hs1 selector record value, a boolean indicating whether it has changed since the previous check, a list of fields that changed with their before and after values, and a timestamp of when the record was last seen. Previous results are stored 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/dkim-hs1-selector-change-watch-83d39669/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)