Summary
A straightforward email validation service that checks syntax, MX records, and flags disposable addresses, then returns a quality score from 0 to 100. Runs as a remote MCP server over SSE and charges per verification using x402 micropayments in USDC. You'd reach for this when your agent needs to validate user input or clean email lists without spinning up your own infrastructure. The repository shows it's built in TypeScript and deployed at email-verification.api.klymax402.com, though the actual MCP tools and prompts aren't documented in the source. The micropayment model means you pay only for what you use rather than maintaining an API subscription.
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Public tool metadata for what this MCP can expose to an agent.
2 tools
email_verify_addressVerify 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 quality1 params
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
Parameters* required
emailstringEmail address to verify (e.g. user@example.com)
email_verify_batchUse this when you need to validate multiple email addresses at once (up to 100). Returns a JSON array of verification results plus summary counts. 1. results (array) -- each entry has valid, syntax,1 params
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. 1. results (array) -- each entry has valid, syntax,
Parameters* required
emailsarrayArray of email addresses (max 100)
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":"user@example.com"}'
# -> 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. user@example.com) |
Example response:
{"valid":true,"syntax":true,"mx":true,"disposable":false,"role":false,"free":true,"score":85,"email":"john@gmail.com"}
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":"a@test.com","valid":true,"score":90},{"email":"b@mailinator.com","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
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Plug Mailtrap into your AI workflow and let it handle the email.
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