| name | email |
| description | Send emails, buy forwarding inboxes, manage custom subdomains, and read messages programmatically via x402.
USE FOR:
- Sending emails (one-off or from custom addresses)
- Buying a forwarding inbox (username@stableemail.dev)
- Purchasing custom email subdomains (you@yourname.stableemail.dev)
- Reading and managing inbox messages programmatically
- Setting up catch-all forwarding for subdomains
- Managing authorized signers for shared subdomains
TRIGGERS:
- "send email", "email this to", "notify by email"
- "buy inbox", "forwarding address", "email inbox"
- "custom domain", "subdomain", "email subdomain"
- "read emails", "check inbox", "list messages"
- "email address", "disposable email", "temporary email"
ALWAYS use `npx agentcash@latest fetch` for stableemail.dev endpoints.
IMPORTANT: Use exact endpoint paths from the Quick Reference table below.
|
| metadata | {"version":2} |
Email with StableEmail
Send emails, manage inboxes, and run custom subdomains via x402 payments at https://stableemail.dev.
Setup
See rules/getting-started.md for installation and wallet setup.
Quick Reference
| Task | Endpoint | Price |
|---|
| Send email (shared) | https://stableemail.dev/api/send | $0.02 |
| Buy subdomain | https://stableemail.dev/api/subdomain/buy | $5.00 |
| Send from subdomain | https://stableemail.dev/api/subdomain/send | $0.005 |
| Buy inbox | https://stableemail.dev/api/inbox/buy | $1.00 |
| Send from inbox | https://stableemail.dev/api/inbox/send | $0.005 |
| Top up inbox (30d) | https://stableemail.dev/api/inbox/topup | $1.00 |
| Top up inbox (90d) | https://stableemail.dev/api/inbox/topup/quarter | $2.50 |
| Top up inbox (365d) | https://stableemail.dev/api/inbox/topup/year | $8.00 |
| List inbox messages | https://stableemail.dev/api/inbox/messages | $0.001 |
| Read inbox message | https://stableemail.dev/api/inbox/messages/read | $0.001 |
| Create subdomain inbox | https://stableemail.dev/api/subdomain/inbox/create | $0.25 |
| List subdomain messages | https://stableemail.dev/api/subdomain/inbox/messages | $0.001 |
| Read subdomain message | https://stableemail.dev/api/subdomain/inbox/messages/read | $0.001 |
Free Management Endpoints
| Task | Endpoint |
|---|
| Subdomain status | GET https://stableemail.dev/api/subdomain/status?subdomain=name |
| Update subdomain | POST https://stableemail.dev/api/subdomain/update |
| Manage signers | POST https://stableemail.dev/api/subdomain/signers |
| Inbox status | GET https://stableemail.dev/api/inbox/status?username=name |
| Update inbox | POST https://stableemail.dev/api/inbox/update |
| Cancel inbox | POST https://stableemail.dev/api/inbox/cancel |
| Delete message | POST https://stableemail.dev/api/inbox/messages/delete |
| List subdomain inboxes | POST https://stableemail.dev/api/subdomain/inbox/list |
| Delete subdomain inbox | POST https://stableemail.dev/api/subdomain/inbox/delete |
| Update subdomain inbox | POST https://stableemail.dev/api/subdomain/inbox/update |
| Delete subdomain message | POST https://stableemail.dev/api/subdomain/inbox/messages/delete |
Free endpoints use SIWX wallet authentication (handled automatically by npx agentcash@latest fetch).
Send an Email
Send from the shared relay@stableemail.dev address:
npx agentcash@latest fetch https://stableemail.dev/api/send -m POST -b '{
"to": ["recipient@example.com"],
"subject": "Hello from x402",
"html": "<h1>Hi!</h1><p>This email was sent via x402 payments.</p>",
"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:
{
"attachments": [{
"content": "base64-encoded-content...",
"contentType": "application/pdf",
"filename": "report.pdf"
}]
}
For calendar invites, use contentType: "text/calendar; method=REQUEST".
Forwarding Inbox
Buy username@stableemail.dev for $1/month. Emails are forwarded to your real address and/or retained for programmatic access.
Buy an Inbox
npx agentcash@latest 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
npx agentcash@latest fetch https://stableemail.dev/api/inbox/send -m POST -b '{
"username": "alice",
"to": ["bob@example.com"],
"subject": "Hello",
"html": "<p>Hi Bob</p>",
"text": "Hi Bob"
}'
Top Up Inbox
npx agentcash@latest 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
npx agentcash@latest 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
npx agentcash@latest fetch https://stableemail.dev/api/inbox/update -m POST -b '{"username": "alice", "retainMessages": true}'
List Messages
npx agentcash@latest fetch https://stableemail.dev/api/inbox/messages -m POST -b '{"username": "alice", "limit": 20}'
Read a Message
npx agentcash@latest 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.stableemail.dev for $5 one-time. Send from any address on your subdomain for $0.005/email.
Buy a Subdomain
npx agentcash@latest 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
npx agentcash@latest fetch https://stableemail.dev/api/subdomain/send -m POST -b '{
"from": "support@yourname.stableemail.dev",
"to": ["customer@example.com"],
"subject": "Your order confirmation",
"html": "<p>Thank you for your order!</p>"
}'
Create Subdomain Inboxes
Create per-address inboxes on your subdomain ($0.25 each, max 100):
npx agentcash@latest 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:
npx agentcash@latest 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:
npx agentcash@latest 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:
<img src="https://f.stableupload.dev/abc/photo.png" alt="Photo" />
Most email clients strip data URIs — always use hosted URLs.
Workflows
Quick Send
Set Up Professional Email
Programmatic Mailbox
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 |
