# Northline WebKit Email Domain Check

> Northline WebKit Email Domain Check is a paid API for AI agents from northline-webkit.northline-c86.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Checks an email address or domain for deliverability, provider type (free/disposable), DMARC policy, and mail provider identity

## Facts

- Endpoint: GET https://northline-webkit.northline-c86.workers.dev/v1/email/check?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/northline-webkit-email-domain-check-4d885065
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FmuCgRFB4TLwLs81OXp0i

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 northline-webkit-email-domain-check-4d885065
```

Example prompt: Can you check whether the email address user@tempmail.com is from a disposable or free provider, whether that domain actually accepts mail, and what its DMARC policy is?

## When to prefer this

Use this endpoint when you need a quick, no-signup, pay-per-call check on an email address or domain covering deliverability, provider classification, disposable detection, and DMARC policy in a single call. Prefer it over building your own DNS/MX/DMARC lookups when you want a unified result with provider identification (e.g. 'Google Workspace') and disposable-provider flagging without API key management.

## Known failure modes

- Missing required 'email' query parameter returns an error
- Invalid or malformed email/domain string may return an error or incomplete result
- Domains with no MX records may return acceptsMail: false
- DMARC lookup may return partial data if DNS is unresponsive
- Payment failure via x402 prevents the call from completing

## How this service works

Pay-per-call web and domain utilities for AI agents: URL to Markdown, link preview metadata, links, uptime/redirect check, DNS, email-domain check, WHOIS/RDAP, robots.txt and a one-call domain report. x402 (USDC on Base), no API key, no signup.

## Output

Returns a JSON object with: the normalized domain, whether it accepts mail, whether it is a free email provider, whether it is disposable, the detected mail provider name (e.g. 'Google Workspace'), the DMARC policy (e.g. 'none', 'quarantine', 'reject'), and an array of flags such as 'free_email_provider'.

## 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": [
      "email"
     ],
     "properties": {
      "email": {
       "type": "string",
       "description": "Email address or bare domain"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "dmarc": {
   "policy": "none"
  },
  "flags": [
   "free_email_provider"
  ],
  "domain": "gmail.com",
  "disposable": false,
  "acceptsMail": true,
  "freeProvider": true,
  "mailProvider": "Google Workspace"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/northline-webkit-email-domain-check-4d885065/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from northline-webkit.northline-c86.workers.dev](https://www.zero.xyz/host/northline-webkit.northline-c86.workers.dev/llms.txt)