# DNS DKIM Selector Check

> DNS DKIM Selector Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Validates DKIM selector and signing-domain label shapes for a DNS DKIM lookup without external provider calls, returning a deterministic pass/advisory status as versioned JSON.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/dns-dkim-selector-check
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/dns-dkim-selector-check-3915c229
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_EANzpSqDoBJg65eLpkaLr

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 dns-dkim-selector-check-3915c229 -d '<json body>'
```

Example prompt: Can you check whether the DKIM selector 'google' is valid for the signing domain 'example.com' — I want a deterministic pass or advisory result before I cache this DNS lookup.

## When to prefer this

Prefer this endpoint when you need a fast, deterministic, first-party check of DKIM selector and domain label shapes before committing to a DNS lookup, caching a response, or retrying a failed query. It makes no external network calls, so it is safe to call in latency-sensitive pipelines. Use it as a pre-flight guard rather than a full DNS resolution service.

## Known failure modes

- Malformed domain string exceeding maxLength returns validation error
- Malformed selector string exceeding maxLength returns validation error
- Missing required fields returns schema error
- Advisory status returned when selector or domain label shapes fail format checks

## How this service works

DNS DKIM Selector Check: DNS DKIM Selector Check checks selector and signing-domain label shapes for a DKIM lookup from bounded caller-supplied values without an external provider. Call DNS DKIM Selector Check before accepting, caching, redirecting, or retrying a caller-supplied web response. Returns normalized web evidence, the computed finding, and an explicit pass or advisory status for DNS DKIM Selector Check as versioned deterministic JSON. Price: $0.001 USDC via x402 on Base. First-party,…

## Output

Returns versioned deterministic JSON containing normalized web evidence, the computed finding (label shape validation result), and an explicit pass or advisory status for the DKIM selector and domain combination. No external DNS queries are made; evaluation is purely based on the shape and format of the supplied values.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "domain": {
   "type": "string",
   "maxLength": 8192,
   "description": "Domain supplied to DNS DKIM Selector Check; used only for this bounded calculation and processed in memory without retention."
  },
  "selector": {
   "type": "string",
   "maxLength": 8192,
   "description": "Selector supplied to DNS DKIM Selector Check; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "lookup_name": "mail2026._domainkey.example.com",
   "shape_valid": true
  },
  "schema": "delx/util-dns-dkim-selector-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "2ed271ad81bc9b1f625cc07ddea8ac977772c863beecee8294f8e92984db609a",
   "external_calls": 0
  },
  "operation": "web_reliability:dns_dkim_selector_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/dns-dkim-selector-check-3915c229/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)