# FastX402 Email Auth Check > FastX402 Email Auth Check is a paid API for AI agents from fastx402.tools, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-18). Audits a domain or email address for email authentication configuration including SPF, DKIM, DMARC, BIMI, MX, MTA-STS, and TLS-RPT records, returning a scored grade. ## Facts - Endpoint: GET https://fastx402.tools/email-auth-check?utm_source=zero.xyz - Price: $0.002/call - Payment: x402 - Status: unknown - Last checked: 2026-10-18 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/fastx402-email-auth-check-88d2570b - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KE2ts-XMpm7Sb3NgQfrkW 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 fastx402-email-auth-check-88d2570b ``` Example prompt: Can you audit the email authentication setup for acme.com — check its SPF, DKIM, DMARC, BIMI, MX, and MTA-STS records and give me an overall security grade? ## When to prefer this Choose this endpoint when you need a comprehensive, scored audit of all major email authentication mechanisms (SPF, DKIM, DMARC, BIMI, MTA-STS, TLS-RPT) for a domain in a single call without needing an API key or subscription. It is ideal for agents performing one-off domain audits, pre-campaign deliverability checks, or vendor security vetting at $0.002 per call via x402 micropayment. ## Known failure modes - Domain does not exist — 'exists: false' returned with no auth data - DNS timeout or lookup failure for specific records — partial results with missing fields - Invalid domain or email format in query parameter — 400 Bad Request - More than 10 extra DKIM selectors requested — validation error - Payment failure via x402 — 402 Payment Required before data is returned ## How this service works 200 pay-per-call tools for AI agents, from $0.001 per request in USDC on Base or Solana with x402. No account, no API key. ## Output A JSON object containing the domain's MX records, SPF record details (including DNS lookup count), DKIM keys found (selector, key type, strength, revoked status), DMARC policy (policy, subdomain policy, RUA/RUF addresses, alignment modes), BIMI presence, MTA-STS and TLS-RPT status, a list of actionable findings with severity levels, an overall numeric score (0–100), and a letter grade (e.g. A, B, C). ## Request schema (JSON Schema) ```json { "type": "object", "$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", "description": "Domain (or an email address) to audit" }, "selectors": { "type": "string", "description": "Optional extra DKIM selectors, comma-separated (max 10)" } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object", "properties": { "mx": { "type": "array", "items": { "type": "object", "properties": { "host": { "type": "string" }, "priority": { "type": "integer" } } } }, "spf": { "type": "object", "properties": { "all": { "type": "string" }, "record": { "type": "string" }, "present": { "type": "boolean" }, "dnsLookups": { "type": "integer" } } }, "bimi": { "type": "boolean" }, "dkim": { "type": "object", "properties": { "found": { "type": "array", "items": { "type": "object", "properties": { "keyType": { "type": "string" }, "revoked": { "type": "boolean" }, "selector": { "type": "string" }, "strength": { "type": "string" } } } }, "selectorsChecked": { "type": "integer" } } }, "dmarc": { "type": "object", "properties": { "pct": { "type": "integer" }, "rua": { "type": "string" }, "ruf": { "type": "string" }, "aspf": { "type": "string" }, "adkim": { "type": "string" … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "mx": [ { "host": "github-com.mail.protection.outlook.com", "priority": 0 } ], "spf": { "all": "~all", "record": "v=spf1 ip4:192.30.252.0/22 include:spf.protection.outlook.com include:_netblocks.google.com ... ~all", "present": true, "dnsLookups": 10 }, "bimi": false, "dkim": { "found": [ { "keyType": "rsa", "revoked": false, "selector": "google", "strength": "rsa-2048-or-more" }, { "keyType": "rsa", "revoked": false, "selector": "k1", "strength": "rsa-1024-or-less" } ], "selectorsChecked": 20 }, "dmarc": { "pct": 100, "rua": "mailto:dmarc@github.com", "ruf": "mailto:dmarc@github.com", "aspf": "r", "adkim": "r", "policy": "quarantine", "record": "v=DMARC1; p=quarantine; sp=reject; pct=100; rua=mailto:dmarc@github.com; ruf=mailto:dmarc@github.com; fo=1", "present": true, "subdomainPolicy": "reject" }, "grade": "B", "score": 80, "domain": "github.com", "exists": true, "mtaSts": false, "nullMx": false, "tlsRpt": false, "findings": [ { "area": "dkim", "message": "selector k1 uses a weak (<=1024-bit) RSA key", "severity": "warning" } ] } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastx402-email-auth-check-88d2570b/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from fastx402.tools](https://www.zero.xyz/host/fastx402.tools/llms.txt)