email.validate

Validate an email address and return structured signals: RFC syntax validity (isSyntaxValid + reason if not), the normalized address with split local/domain, and boolean flags for isDisposable (throwaway/temp-mail domain), isRoleAccount (info@, support@, admin@, …), and isFreeProvider (gmail/outlook/yahoo/icloud/…). With checkMx (default true) it also reports hasMxRecords — whether the domain publishes MX records, looked up live via DNS-over-HTTPS — plus the MX hosts. IMPORTANT: this is NOT a deliverability or mailbox-existence guarantee (catch-all domains, greylisting, and privacy relays make that impossible to assert from a single lookup); hasMxRecords reflects DNS MX presence only. Useful for signup-flow hygiene, lead scrubbing, and flagging disposable/role addresses before sending.

price
$0.0010 USDC per call
method
GET/api/email/validate
payment
x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)
auth
None. Sign the payment, retry with PAYMENT-SIGNATURE.
tier
Tier 0 — no paid upstream

Parameters

NameTypeDescription
emailrequiredstring
min 1 chars · max 320 chars
checkMxboolean

Code samples

cURLbash
# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/email/validate?email=example&checkMx=false'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/email/validate?email=example&checkMx=false' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>'

# Or use the canonical runner (handles probe → sign → retry):
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/email/validate?email=example&checkMx=false'
TypeScript / Node — @2sio/sdktypescript
import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.email.validate({
  "email": "example",
  "checkMx": false
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)
Python — 2siopython
import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.email.validate(email="example", checkMx=False)

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)
MCP — Claude Desktop / AgentKit / any MCP hostjson
// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
//    EVM_PRIVATE_KEY funds x402 payments per call.

// claude_desktop_config.json
{
  "mcpServers": {
    "2sio": {
      "command": "npx",
      "args": ["-y", "@2sio/mcp"],
      "env": { "EVM_PRIVATE_KEY": "0x..." }
    }
  }
}

// 2. Once the server is running, agents call this tool via standard MCP:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "email.validate",
    "arguments": {
      "email": "example",
      "checkMx": false
    }
  }
}

Response

FieldTypeDescription
okboolean
one of: true
itemsarray
totalintegerTotal matching rows upstream; null when unknown.
sourceobject
Example response datajson
{
  "ok": true,
  "items": [
    {
      "email": "example",
      "normalized": "example",
      "local": "example",
      "domain": "example",
      "isSyntaxValid": false,
      "isDisposable": false,
      "isRoleAccount": false,
      "isFreeProvider": false,
      "hasMxRecords": false,
      "mxHosts": [
        "example"
      ],
      "reason": "example",
      "note": "example"
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

Discovery

2s.io is x402-native. Every call is paid per-request from a USDC-funded EVM wallet on Base — no signup, no API keys, no monthly fees. Source code: github.com/2s-io/sdk.