Email Verification API
Real-time email verification API. Syntax, MX, disposable detection, role-based flags, quality score 0-100. Built for agent outreach pipelines. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.
Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.
Quickstart -- MCP
Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):
{
"mcpServers": {
"email-verification": {
"url": "https://email-verification.api.klymax402.com/mcp"
}
}
}
Quickstart -- HTTP (x402)
curl -X POST "https://email-verification.api.klymax402.com/api/verify" \
-H "Content-Type: application/json" \
-d '{"email":"[email protected]"}'
# -> 402 Payment Required, with an x402 payment challenge in the response body
Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.
Tools
| Tool | Method | Path | Price | Description |
|---|---|---|---|---|
email_verify_address | POST | /api/verify | $0.005 | Verify a single email address |
email_verify_batch | POST | /api/verify/batch | $0.03 | Verify up to 100 email addresses in batch |
email_verify_address
Verify email deliverability in real-time. Alternative to Hunter email-verifier at 15x lower cost. Returns a structured JSON report with syntax, MX, disposable detection, role-based flags, and quality score 0-100.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
email | string | yes | Email address to verify (e.g. [email protected]) |
Example response:
{"valid":true,"syntax":true,"mx":true,"disposable":false,"role":false,"free":true,"score":85,"email":"[email protected]"}
When to use: sending outreach emails, adding contacts to CRM, or processing signups. Essential for verifying email deliverability, cleaning email lists, detecting fake registrations, and qualifying leads. Drop-in replacement for Hunter email verification.
Not for: finding emails (use email_find_by_name), person data (use person_enrich_from_email), domain deliverability audit (SPF/DKIM/DMARC) (use email_audit_deliverability).
email_verify_batch
Use this when you need to validate multiple email addresses at once (up to 100). Returns a JSON array of verification results plus summary counts.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
emails | array | yes | Array of email addresses (max 100) |
Example response:
{"results":[{"email":"[email protected]","valid":true,"score":90},{"email":"[email protected]","valid":false,"score":10}],"summary":{"total":2,"valid":1,"invalid":1,"disposable":1}}
When to use: bulk list cleaning, CRM hygiene, or pre-campaign validation. Essential when you have 5+ emails to verify at once.
Not for: single emails (use email_verify_address), finding emails (use email_find_by_name).
Example agent prompts
- "Verify email deliverability in real-time"
- "Validate multiple email addresses at once (up to 100)"
Payment
- Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
- Network: Base L2 (
eip155:8453) - Asset: USDC
- Facilitator: Coinbase CDP (primary), PayAI (fallback)
- Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)
Part of klymax402
100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.
- Catalog: https://klymax402.com/llms.txt
- Full API reference: https://klymax402.com/llms-full.txt
- Live stats: https://klymax402.com/stats
License
MIT