# DKIM Selector Lookup – ProtonMail

> DKIM Selector Lookup – ProtonMail 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 'protonmail' selector of a given domain, confirming key type, length, testing flag, and revocation status.

## Facts

- Endpoint: GET https://dns.intel.rallylive.ca/dns/dkim/protonmail?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-lookup-protonmail-3f3e0a8c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hUKuWLbGYihoejtBWXBJq

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-lookup-protonmail-3f3e0a8c
```

Example prompt: Can you check if example.com has a valid ProtonMail DKIM key configured — I want to know the key type, length, and whether it's been revoked?

## When to prefer this

Use this endpoint when you specifically need to verify the ProtonMail DKIM selector (protonmail._domainkey) for a domain, as opposed to other selectors like 'google' or 'default'. Ideal for auditing ProtonMail-hosted email configurations, troubleshooting DKIM signing failures for ProtonMail senders, or checking revocation status of ProtonMail signing keys.

## Known failure modes

- Domain does not have a protonmail._domainkey TXT record — returns not found or empty result
- DNS resolution fails via Cloudflare DoH — network or timeout error
- Domain is invalid or malformed — returns validation error
- Record exists but p= is empty — key is revoked, flagged in response
- Payment not attached or insufficient — returns 402 Payment Required

## How this service works

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

## Output

Returns parsed details of the protonmail._domainkey.<domain> TXT record: v= and k= tag values, key type (e.g. RSA), public-key bit length, whether the testing flag is set, and whether the key is revoked (empty p= field). Confirms whether mail signed with the protonmail 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-lookup-protonmail-3f3e0a8c/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)