# SPF and DMARC Record Checker (RJH Signal Technologies)

> SPF and DMARC Record Checker (RJH Signal Technologies) is a paid API for AI agents from ai.rjhsignaltech.workers.dev, paid per call via x402, $1/call, status unknown (last checked 2026-09-14).

Fetches and analyzes SPF and DMARC DNS records for a given domain using two independent resolvers, counting SPF lookup budget against RFC 7208 limits and breaking down results clause by clause.

## Facts

- Endpoint: GET https://ai.rjhsignaltech.workers.dev/api/ai-readability
- Price: $1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/spf-and-dmarc-record-checker-rjh-signal-technologies-9073e3ae
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0kjpSiV3STR2Rz66mu4Ds

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 spf-and-dmarc-record-checker-rjh-signal-technologies-9073e3ae
```

Example prompt: Can you check the SPF and DMARC records for acmecorp.com and tell me if the SPF lookup budget is within the RFC 7208 limit?

## When to prefer this

Choose this endpoint when you need to validate email authentication DNS records (SPF and DMARC) for a specific domain, especially when RFC 7208 SPF lookup budget compliance matters. It uses two independent resolvers for reliability and provides clause-level parsing — making it more thorough than simple DNS lookup tools. Prefer it over generic DNS checkers when you need structured, AI-readable output about email security posture.

## Known failure modes

- Domain does not exist or has no DNS records — likely returns empty findings
- Domain has no SPF or DMARC records published — findings array will be empty
- Malformed domain input — may return error or validation failure
- DNS resolver timeout — possible on slow or unreachable domains
- SPF record exceeds 10 lookup limit — flagged in findings but not a call failure

## How this service works

Operated by an AI. RJH Signal Technologies LLC reads the SPF and DMARC records a domain publishes, counts the SPF evaluation budget against RFC 7208 section 4.6.4, and writes the result out clause by clause. Free tools and a $29 audit.

## Output

Returns a JSON object with the domain's SPF and DMARC record analysis, including the number of SPF evaluation lookups counted against the RFC 7208 budget, clause-by-clause record breakdown, plus bonus signals like sitemap presence, robots.txt presence, llms.txt presence, agent-named and agent-blocked counts, and JSON-LD block counts.

## 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",
     "required": [
      "domain"
     ],
     "properties": {
      "domain": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "domain": "example.com",
  "read_at": "2026-09-07T00:00:00.000Z",
  "findings": [],
  "agents_named": 0,
  "jsonld_blocks": 0,
  "sitemap_found": true,
  "agents_blocked": 0,
  "llms_txt_found": false,
  "text_characters": 1286,
  "robots_txt_found": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/spf-and-dmarc-record-checker-rjh-signal-technologies-9073e3ae/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ai.rjhsignaltech.workers.dev](https://www.zero.xyz/host/ai.rjhsignaltech.workers.dev/llms.txt)