# Lookproof DKIM Selector Discovery

> Lookproof DKIM Selector Discovery is a paid API for AI agents from api.lookproof.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-31).

Probes 27 common DKIM selectors for a domain and validates each found key's type, size, revocation status, and testing flag

## Facts

- Endpoint: GET https://api.lookproof.dev/v1/mail/dkim-discover?utm_source=zero.xyz
- Price: $0.02/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-selector-discovery-31cfe3c0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rlkyGRy284SlpHovpqdhi

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-selector-discovery-31cfe3c0
```

Example prompt: Can you discover what DKIM selectors and keys are configured for sendgrid.com — I don't know the selector name, so try the common ones and tell me if any keys look revoked or are still in test mode?

## When to prefer this

Use this endpoint when you need to discover DKIM keys for a domain but do not know the selector name in advance. It covers 27 selectors from the most popular ESPs (Google Workspace, Microsoft 365, Mailchimp, SendGrid, Mailgun, Zoho, Proton, Fastmail, Mailjet, Amazon SES) plus generic names. Prefer this over a raw DNS TXT lookup when you want automatic multi-selector probing and key validation (type, size, revocation, testing flag) in a single call.

## Known failure modes

- Domain does not exist — returns empty results or DNS NXDOMAIN
- All 27 selectors have no DNS records — returns empty list, not an error
- DNS timeout or resolver failure — may return partial or empty results
- Domain is valid but uses non-standard selectors not in the 27-selector set — returns empty list
- Malformed domain input — may return validation error

## 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

A list of discovered DKIM selectors and their associated public key details: key type (e.g. RSA, Ed25519), key size in bits, whether the key is revoked (empty p= field), and whether the testing flag (t=y) is set. Selectors that return no DNS record are silently skipped. An empty result means none of the 27 tried selectors resolved, which is a hint but not proof that DKIM is absent.

## 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": "DomainInput",
     "required": [
      "domain"
     ],
     "properties": {
      "domain": {
       "type": "string",
       "title": "Domain",
       "examples": [
        "example.com"
       ],
       "maxLength": 1024,
       "minLength": 1
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/lookproof-dkim-selector-discovery-31cfe3c0/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)