# StableEmail Buy Inbox

> StableEmail Buy Inbox is a paid API for AI agents from StableEmail at stableemail.dev, paid per call via MPP or x402, $1/call, status unknown (last checked 2026-10-10, last successful call 2026-08-21).

Purchases a new email inbox on stableemail.dev for $1 USDC, valid for 30 days, with optional email forwarding or programmatic message access.

## Facts

- Endpoint: POST https://stableemail.dev/api/inbox/buy?utm_source=zero.xyz
- Price: $1/call
- Payment: MPP, x402
- Status: unknown
- Last checked: 2026-10-10
- Last successful call: 2026-08-21
- Success rate: 100% of calls made through Zero
- Rating: 5.0 / 5 from 1 review
- Activations on Zero: 3
- Provider: StableEmail
- Docs: https://stableemail.dev
- Website: https://stableemail.dev
- Tags: email, send, inbox, forwarding, subdomain, social
- Canonical page: https://www.zero.xyz/c/stableemail-buy-150c910b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nmLcALAeo4RfdcjYRgI01

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability stableemail-buy-150c910b -d '<json body>'
```

Example prompt: Buy me a new inbox on StableEmail for the username 'devtest42' and forward everything to me@mycompany.com.

## When to prefer this

Use this endpoint when you need to create a new, fresh email inbox from scratch on stableemail.dev — either as a forwarding address (messages relayed to your real inbox) or as a programmatic mailbox you can poll via the messages API. Prefer this over the Topup endpoint (which renews an existing inbox) or the subdomain purchase endpoint (which buys a custom subdomain). Ideal for temporary, disposable, or test inboxes where no persistent account setup is wanted.

## Known failure modes

- Username already taken — returns a conflict/400 error
- Username fails regex validation (too short, contains consecutive hyphens, starts/ends with hyphen) — returns 400 validation error
- Invalid forwardTo email format — returns 400 validation error
- Payment failure or insufficient USDC balance — returns 402 payment required
- Service unavailable — returns 5xx error

## How this service works

Buy an inbox on stableemail.dev ($1, 30 days). forwardTo is optional — omit it to use as a programmatic mailbox via the messages API (retainMessages enabled automatically). Message content and attachments are retained for 90 days.

## Output

Returns the newly created inbox details including the full email address (username@stableemail.dev), expiry timestamp (30 days from creation), and confirmation that message retention is enabled (90 days for content and attachments). If forwardTo was omitted, the response confirms retainMessages is active so messages can be retrieved via the messages API.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "username"
 ],
 "properties": {
  "username": {
   "type": "string",
   "allOf": [
    {
     "pattern": "^[a-z0-9][a-z0-9-]{1,28}[a-z0-9]$"
    },
    {
     "pattern": "^(?!.*--)"
    }
   ]
  },
  "forwardTo": {
   "type": "string",
   "format": "email",
   "pattern": "^(?!\\.)(?!.*\\.\\.)([A-Za-z0-9_'+\\-\\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\\-]*\\.)+[A-Za-z]{2,}$"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stableemail-buy-150c910b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stableemail.dev](https://www.zero.xyz/host/stableemail.dev/llms.txt)