# DKIM GMass Selector Lookup

> DKIM GMass Selector 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 'gmass' selector of a given domain, confirming email signing validity and key health.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/dkim/gmass?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-gmass-selector-lookup-4cb067c5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_93cNTt5hVlvBYQk5f9N4B

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-gmass-selector-lookup-4cb067c5
```

Example prompt: Check the DKIM gmass selector for acme.com — I want to know if the key is valid, what type and length it is, and whether it's been revoked.

## When to prefer this

Use this endpoint when you specifically need to verify the GMass DKIM selector (gmass._domainkey) for a domain — for example, when auditing GMass email campaign deliverability, debugging DKIM failures for GMass-sent mail, or confirming a domain is correctly configured for GMass sending. Prefer this over generic DKIM tools when the selector is known to be 'gmass' and you need parsed key metadata including revocation and testing flags.

## Known failure modes

- Domain has no gmass._domainkey TXT record (record not found)
- DNS lookup timeout or Cloudflare DoH unavailability
- Malformed TXT record that cannot be parsed
- Empty p= field indicating a revoked key (returned as data, not error)
- Invalid domain name input

## How this service works

DKIM public key for selector "gmass" of a domain: looks up gmass._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 gmass selector will verify. $0.01 per lookup.

## Output

Returns parsed details of the gmass._domainkey.<domain> TXT record including: DKIM version (v=), key type (k=), public key, public-key bit length, whether the testing flag is set, and whether the key is revoked (empty p= field). Confirms if mail signed with the gmass selector will successfully verify.

## 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-gmass-selector-lookup-4cb067c5/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)