# agent402.tools Contact Verification

> agent402.tools Contact Verification is a paid API for AI agents from agent402.tools, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-15).

Verifies an email address is deliverable by running syntax validation, MX record lookup, and SPF check in a single bundled call

## Facts

- Endpoint: POST https://agent402.tools/api/skill/contact-verify
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-tools-contact-verification-5fb6eb74
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_THpR5hxhIbQfR4rHfNeNF

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 agent402-tools-contact-verification-5fb6eb74 -d '<json body>'
```

Example prompt: Can you verify that the email address john.smith@acme.com is real and actually deliverable — check the syntax, domain MX records, and SPF settings?

## When to prefer this

Use this endpoint when you need a comprehensive, multi-layer email verification in a single API call rather than stitching together separate DNS, syntax, and SPF tools. It is ideal for pre-send validation before outreach, cleaning contact lists, or confirming a user-supplied email is reachable. Prefer this over single-purpose validators when you need all three signals (syntax, MX, SPF) atomically for $0.06 per check.

## Known failure modes

- Invalid email format provided — syntax check fails immediately before DNS lookups
- Domain has no MX records — email address format valid but domain cannot receive mail
- DNS lookup timeout or network error during MX/SPF check — partial success returned
- SPF check inconclusive due to missing or malformed SPF record on domain
- Payment failure or insufficient USDC balance — call not executed
- Empty or missing email parameter — request rejected with validation error

## How this service works

Bundled execution of the Contact verification workflow - Verify an email address is deliverable - syntax validation plus MX record check on the domain. One x402 payment runs 3 underlying tools (email-validate, dns-lookup, spf-check); partial-success per step.

## Output

Returns a bundled result covering three checks: (1) syntax validation of the email address format, (2) MX record lookup confirming the domain has mail exchange servers configured, and (3) SPF record check. Together these indicate whether the email is likely deliverable, with possible partial-success states if some sub-checks pass and others fail.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "email": {
   "type": "string",
   "description": "Email address to verify (e.g. test@gmail.com)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "args": {
   "email": "test@gmail.com"
  },
  "pack": "contact-verify",
  "steps": [
   {
    "ok": true,
    "slug": "email-validate",
    "result": {}
   },
   {
    "ok": true,
    "slug": "dns-lookup",
    "result": {}
   },
   {
    "ok": true,
    "slug": "spf-check",
    "result": {}
   }
  ],
  "summary": "3/3 steps succeeded"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-contact-verification-5fb6eb74/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)