x402email

Pay-per-send email. No API keys. No accounts. One HTTP request.

How it works

1POST your email to /api/send
2Get back a 402 with payment requirements ($0.001 USDC on Base)
3Pay and resend — email delivered via AWS SES

Example

POST /api/send

{
  "to": ["alice@example.com"],
  "subject": "Hello from x402",
  "text": "Sent and paid in one HTTP request.",
  "replyTo": "you@example.com"
}

Response

HTTP/1.1 402 Payment Required
PAYMENT-REQUIRED: <base64 payment details>

// Pay with any x402 client, then:

{
  "success": true,
  "messageId": "ses-abc123",
  "from": "relay@x402email.com"
}

Endpoints

Endpoint	Price	Auth
`POST /api/send` Send from relay@x402email.com	$0.001	x402
`POST /api/subdomain/buy` Purchase yourname.x402email.com	$5	x402 + SIWX
`POST /api/subdomain/send` Send from your subdomain	$0.001	x402 + SIWX
`POST /api/subdomain/signers` Add/remove authorized wallets	Free	SIWX
`GET /api/subdomain/status` Check DNS/SES verification	Free	SIWX

Custom subdomains

Buy yourname.x402email.com for $5. Send from any address on your subdomain. Add up to 50 authorized wallet signers via SIWX.

Discovery

x402 resource discovery at /.well-known/x402

Agent instructions at /llms.txt