email

Original：🇺🇸 English

Translated

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@x402email.com) - Purchasing custom email subdomains (you@yourname.x402email.com) - 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 fetch` for stableemail.dev endpoints. IMPORTANT: Use exact endpoint paths from the Quick Reference table below.

2installs

Sourcemerit-systems/agentcash-skills

Added on2026-02-21

NPX Install

npx skill4agent add merit-systems/agentcash-skills email

SKILL.md Content

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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 fetch

).

Send an Email

Send from the shared

relay@x402email.com

address:

bash

npx agentcash 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:

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": "<p>Hi Bob</p>",
  "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": "<p>Thank you for your order!</p>"
}'

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

<img src="https://f.stableupload.dev/abc/photo.png" alt="Photo" />

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

email

NPX Install

Tags

SKILL.md Content

Email with StableEmail

Setup

Quick Reference

Free Management Endpoints

Send an Email

Forwarding Inbox

Buy an Inbox

Send from Inbox

Top Up Inbox

Cancel and Refund

Read Inbox Messages

Enable Retention

List Messages

Read a Message

Custom Subdomains

Buy a Subdomain

Send from Subdomain

Create Subdomain Inboxes

Catch-All Forwarding

Manage Authorized Signers

Images in Emails

Workflows

Quick Send

Set Up Professional Email

Programmatic Mailbox

Cost Estimation