This email was sent via x402 payments.
", "text": "Hi! This email was sent via x402 payments.", "replyTo": "your-real-email@example.com" }' ``` **Parameters:** - `to` — array of recipient emails (required) - `subject` — email subject (required) - `html` and/or `text` — email body (at least one required) - `replyTo` — reply-to address (optional but recommended) - `attachments` — array of `{content, contentType, filename}` (optional, max 5, base64 encoded, ~3.75MB limit each) **Attachment example:** ```json { "attachments": [{ "content": "base64-encoded-content...", "contentType": "application/pdf", "filename": "report.pdf" }] } ``` For calendar invites, use `contentType: "text/calendar; method=REQUEST"`. ## Forwarding Inbox Buy `username@x402email.com` for $1/month. Emails are forwarded to your real address and/or retained for programmatic access. ### Buy an Inbox ```bash npx agentcash fetch https://stableemail.dev/api/inbox/buy -m POST -b '{ "username": "alice", "forwardTo": "alice@gmail.com" }' ``` Omit `forwardTo` to use as a programmatic-only mailbox (retainMessages auto-enabled). ### Send from Inbox ```bash npx agentcash fetch https://stableemail.dev/api/inbox/send -m POST -b '{ "username": "alice", "to": ["bob@example.com"], "subject": "Hello", "html": "Hi Bob
", "text": "Hi Bob" }' ``` ### Top Up Inbox ```bash npx agentcash fetch https://stableemail.dev/api/inbox/topup -m POST -b '{"username": "alice"}' ``` Anyone can top up any inbox. Top-ups stack. Bulk discounts: 90 days/$2.50 (17% off), 365 days/$8 (34% off). ### Cancel and Refund ```bash npx agentcash fetch https://stableemail.dev/api/inbox/cancel -m POST -b '{"username": "alice"}' ``` Returns pro-rata USDC refund on-chain automatically. ## Read Inbox Messages Enable message retention, then read messages programmatically. ### Enable Retention ```bash npx agentcash fetch https://stableemail.dev/api/inbox/update -m POST -b '{"username": "alice", "retainMessages": true}' ``` ### List Messages ```bash npx agentcash fetch https://stableemail.dev/api/inbox/messages -m POST -b '{"username": "alice", "limit": 20}' ``` ### Read a Message ```bash npx agentcash fetch https://stableemail.dev/api/inbox/messages/read -m POST -b '{"messageId": "msg_abc123"}' ``` Returns full message with from, to, subject, date, text, html, and attachments. ## Custom Subdomains Buy `yourname.x402email.com` for $5 one-time. Send from any address on your subdomain for $0.005/email. ### Buy a Subdomain ```bash npx agentcash fetch https://stableemail.dev/api/subdomain/buy -m POST -b '{"subdomain": "yourname"}' ``` Rules: 3-30 chars, lowercase alphanumeric + hyphens. DNS verification takes ~5 minutes. ### Send from Subdomain ```bash npx agentcash fetch https://stableemail.dev/api/subdomain/send -m POST -b '{ "from": "support@yourname.x402email.com", "to": ["customer@example.com"], "subject": "Your order confirmation", "html": "Thank you for your order!
" }' ``` ### Create Subdomain Inboxes Create per-address inboxes on your subdomain ($0.25 each, max 100): ```bash npx agentcash fetch https://stableemail.dev/api/subdomain/inbox/create -m POST -b '{ "subdomain": "yourname", "localPart": "support", "forwardTo": "team@company.com" }' ``` ### Catch-All Forwarding Forward all unmatched addresses on your subdomain: ```bash npx agentcash fetch https://stableemail.dev/api/subdomain/update -m POST -b '{"subdomain": "yourname", "catchAllForwardTo": "catch-all@company.com"}' ``` ### Manage Authorized Signers Allow other wallets to send from your subdomain: ```bash npx agentcash fetch https://stableemail.dev/api/subdomain/signers -m POST -b '{"action": "add", "subdomain": "yourname", "walletAddress": "0x..."}' ``` ## Images in Emails Host images on StableUpload or AgentUpload, then reference in HTML: ```html
```
Most email clients strip data URIs — always use hosted URLs.
## Workflows
### Quick Send
- [ ] (Optional) Check balance: `npx agentcash wallet info`
- [ ] Send email via `/api/send`
- [ ] Confirm delivery via messageId
### Set Up Professional Email
- [ ] Buy subdomain ($5)
- [ ] Wait for DNS verification (~5 min)
- [ ] Create inboxes for team members ($0.25 each)
- [ ] Set up catch-all forwarding
- [ ] Send from custom addresses ($0.005 each)
### Programmatic Mailbox
- [ ] Buy inbox with no forwardTo ($1)
- [ ] Messages are retained automatically
- [ ] List and read messages via API ($0.001 each)
- [ ] Delete messages when processed (free)
## Cost Estimation
| Task | Cost |
|------|------|
| Send one email (shared) | $0.02 |
| Send one email (subdomain/inbox) | $0.005 |
| Buy inbox (30 days) | $1.00 |
| Buy inbox (1 year) | $1.00 + $8.00 = $9.00 |
| Buy subdomain + 5 inboxes | $5.00 + $1.25 = $6.25 |
| Read 100 messages | $0.10 |