# DKIM Selector S1 Public Key Lookup

> DKIM Selector S1 Public Key Lookup is a paid API for AI agents from dns.intel.rallylive.ca, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Looks up and parses the DKIM public key for the 's1' selector of a given domain via Cloudflare DoH, returning key type, length, testing status, and revocation state.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/dkim/s1?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dkim-selector-s1-public-key-lookup-310c575e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uxw_juB9l0IWAMtSHVrY_

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-selector-s1-public-key-lookup-310c575e
```

Example prompt: Can you check whether example.com has a valid DKIM public key set up for the s1 selector — I want to know if it's revoked, what key type it is, and whether mail signed with that selector would actually verify?

## When to prefer this

Choose this endpoint when you specifically need to inspect the 's1' DKIM selector for a domain — a common selector used by many ESPs and self-hosted mail servers. Prefer it over generic DNS TXT lookups when you need structured parsing of DKIM fields (key type, length, revocation) rather than raw TXT data. Use it for email deliverability checks, domain security audits, or debugging DKIM signing issues tied to the s1 selector.

## Known failure modes

- Domain does not have an s1._domainkey TXT record (NXDOMAIN or empty response)
- DKIM record is malformed and cannot be parsed
- Key is revoked (empty p= field) — endpoint still returns data but flags revocation
- DNS resolution failure via Cloudflare DoH
- Invalid domain name input causing lookup error
- Rate limiting or payment failure (x402)

## How this service works

DKIM public key for selector "s1" of a domain: looks up s1._domainkey.<domain> (TXT, Cloudflare DoH) and parses v=, k=, key type, public-key length, testing flag and whether the key is revoked (empty p=). Confirms that mail signed with the s1 selector will verify. $0.01 per lookup.

## Output

Returns parsed DKIM TXT record fields for the s1._domainkey.<domain> DNS entry, including the DKIM version (v=), key type (k=), public key length in bits, whether the testing flag is set, and whether the key is revoked (empty p= field). Also confirms whether mail signed with the s1 selector will pass DKIM verification.

## 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-selector-s1-public-key-lookup-310c575e/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)