How it works
- 1POST your email to
/api/send - 2Get back a 402 with payment requirements ($0.02 USDC on Base)
- 3Pay and resend — email delivered via AWS SES
Example
{
"to": ["alice@example.com"],
"subject": "Hello from x402",
"text": "Sent and paid in one HTTP request.",
"replyTo": "you@example.com"
}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/sendSend from relay@x402email.com | $0.02 | x402 |
POST /api/subdomain/buyPurchase yourname.x402email.com | $5 | x402 |
POST /api/subdomain/sendSend from your subdomain | $0.005 | x402 |
POST /api/subdomain/signersAdd/remove authorized wallets | Free | SIWX |
GET /api/subdomain/statusCheck DNS/SES verification | Free | SIWX |
POST /api/inbox/buyBuy username@x402email.com (30 days) | $1 | x402 |
POST /api/inbox/topupExtend inbox 30 days | $1 | x402 |
POST /api/inbox/topup/quarterExtend inbox 90 days (save 17%) | $2.50 | x402 |
POST /api/inbox/topup/yearExtend inbox 365 days (save 34%) | $8 | x402 |
POST /api/inbox/sendSend from your inbox address | $0.005 | x402 |
GET /api/inbox/statusCheck inbox status and expiry | Free | SIWX |
POST /api/inbox/updateChange forwarding address | Free | SIWX |
POST /api/inbox/cancelCancel inbox and get pro-rata refund | Free | SIWX |
Forwarding inbox
Buy username@x402email.com for $1/month. Emails forwarded to your real address. Send from your inbox address for $0.005/email. Bulk discounts: 90 days for $2.50 (save 17%), 365 days for $8 (save 34%). Anyone can top up any inbox. Cancel anytime for a pro-rata refund.
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