# Email Validation API

> Email Validation API is a paid API for AI agents from api.kadec0.xyz, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-14).

Validates up to 25 email addresses per call with RFC syntax checks, live MX lookups, disposable-domain detection, role-account flagging, and free-provider flagging, returning an ok/risky/invalid verdict per address.

## Facts

- Endpoint: GET https://api.kadec0.xyz/v1/email-validate
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/email-validation-api-4f499eb3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3p_DArVudN2ImVLdVMIS3

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 email-validation-api-4f499eb3
```

Example prompt: Can you validate these email addresses for me and flag any that are disposable, role-based, or invalid: john.doe@gmail.com, info@acmecorp.com, test123@mailinator.com, jane@startup.io, noreply@bigco.com?

## When to prefer this

Choose this endpoint when you need fast, keyless email validation with disposable-domain detection and role-account flagging in batch (up to 25 at a time) without requiring SMTP probing. It is well-suited for lead list hygiene, signup fraud filtering, and CRM data quality checks where DNS-level verification is sufficient and you want an all-in-one ok/risky/invalid verdict with structured reasons. If you need live SMTP mailbox confirmation (i.e. verifying the specific inbox exists), a full SMTP-probe service would be more appropriate.

## Known failure modes

- Missing or empty 'emails' query parameter returns an error
- More than 25 addresses in a single call may be rejected or truncated
- Malformed comma-separated list may cause parsing errors
- Unknown or unresolvable domains return no-MX verdict rather than confirmed invalid
- Newly created disposable domains not yet in the 8k+ blocklist may pass as ok
- No SMTP probe means a syntactically valid address on a live MX may still not exist as a real mailbox
- Payment failure (x402) if USDC balance is insufficient

## How this service works

Email validation and email list cleaning. Checks each email address for RFC syntax, a live MX record lookup returning the real mail hosts, disposable-domain detection, role-account flags (info@, sales@, noreply@), and a free-provider flag, rolled into a per-address ok/risky/invalid verdict with reasons. Batch up to 25 email addresses per call. Domain-level DNS only, no SMTP mailbox probe. Keyless.

## Output

Returns a per-address verdict of ok, risky, or invalid along with reason codes explaining the result. Each result includes whether an MX record was found (with the actual mail hosts), whether the domain is a known disposable/throwaway domain, whether the address is a role account (e.g. info@, sales@), and whether it uses a free email provider. Up to 25 addresses are processed per call.

## 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",
     "required": [
      "emails"
     ],
     "properties": {
      "emails": {
       "type": "string",
       "description": "comma-separated email addresses, up to 25 per call (a single address works too)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/email-validation-api-4f499eb3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.kadec0.xyz](https://www.zero.xyz/host/api.kadec0.xyz/llms.txt)