# Lookproof DKIM Public Key Validator

> Lookproof DKIM Public Key Validator is a paid API for AI agents from api.lookproof.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).

Fetches and validates the DKIM public key DNS record for a given domain and selector, checking key type, size, revocation status, and syntax with coded findings.

## Facts

- Endpoint: GET https://api.lookproof.dev/v1/mail/dkim?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/lookproof-dkim-public-key-validator-39762cfc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Jr66c0Y6DXhwhcAJDpkdH

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 lookproof-dkim-public-key-validator-39762cfc
```

Example prompt: Can you check whether the DKIM public key for the selector 'google' on domain 'example.com' is published, valid, and not revoked?

## When to prefer this

Use this endpoint when an agent has a specific DKIM selector (from the s= tag of a DKIM-Signature header or from DNS configuration knowledge) and needs to confirm the corresponding public key is correctly published, not revoked, syntactically valid, and of adequate key strength. It is the right choice for email deliverability diagnostics, security audits of mail signing infrastructure, and pre-deployment checks of DKIM configuration. It does not verify actual message signatures — use it purely for DNS-layer key validation.

## Known failure modes

- Domain or selector does not exist in DNS — returns record-not-found finding
- DKIM record is syntactically malformed — returns syntax error codes
- Key is revoked (empty p= field) — returned as a coded finding, not an error
- DNS resolution timeout or upstream resolver failure — returns transient error
- Invalid domain or selector input format — returns validation error
- No DKIM record found at the expected DNS location — returns missing-record finding

## How this service works

Check SPF, DMARC, DKIM, MTA-STS, DNSSEC and more, with results that explain what was found and why. Free browser checks and a pay-per-request API with x402.

## Output

Returns structured details about the DKIM DNS TXT record at selector._domainkey.domain, including the key type (e.g. RSA), key size in bits, whether the key is revoked (empty p= tag), syntax validity, and coded diagnostic findings indicating any issues with the record's publication or content.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "title": "DkimInput",
     "required": [
      "domain",
      "selector"
     ],
     "properties": {
      "domain": {
       "type": "string",
       "title": "Domain",
       "examples": [
        "example.com"
       ],
       "maxLength": 1024,
       "minLength": 1
      },
      "selector": {
       "type": "string",
       "title": "Selector",
       "examples": [
        "selector1"
       ],
       "maxLength": 200,
       "minLength": 1
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/lookproof-dkim-public-key-validator-39762cfc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.lookproof.dev](https://www.zero.xyz/host/api.lookproof.dev/llms.txt)