# StableEmail Subdomain Inbox Create

> StableEmail Subdomain Inbox Create is a paid API for AI agents from stableemail.dev, paid per call via x402, $0.25/call, status unknown (last checked 2026-10-20).

Creates a new email inbox on a StableEmail subdomain for receiving and managing email

## Facts

- Endpoint: POST https://stableemail.dev/api/subdomain/inbox/create?utm_source=zero.xyz
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Success rate: 0% of calls made through Zero
- Activations on Zero: 1
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stableemail-b7c411fb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MyJU46dlQVf6ofg5Jv3K5

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-b7c411fb -d '<json body>'
```

Example prompt: Create a new inbox called 'support' on my StableEmail subdomain so I can start receiving emails there.

## When to prefer this

Use this endpoint when you need to programmatically provision a new receiving email inbox on a pre-purchased StableEmail subdomain. Prefer this over the subdomain purchase endpoint (Buy) when the subdomain already exists and you just need a new mailbox. Ideal for applications that need to dynamically create per-user or per-purpose email addresses at scale.

## Known failure modes

- Subdomain not owned or not verified — returns authorization or ownership error
- Inbox name already exists on the subdomain — returns conflict error
- Insufficient USDC balance to cover $0.25 creation fee — returns payment failure
- Invalid inbox name format (special characters, too long) — returns validation error
- DNS or SES verification not yet complete for subdomain — returns status error

## How this service works

Create inbox on subdomain ($0.25)

## Output

Returns confirmation of the newly created inbox, including the inbox identifier and the full email address provisioned on the subdomain, ready to receive messages.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "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,}$"
  },
  "localPart": {
   "type": "string",
   "pattern": "^[a-z0-9][a-z0-9._+-]{0,62}[a-z0-9]$",
   "maxLength": 64,
   "minLength": 1
  },
  "subdomain": {
   "type": "string",
   "allOf": [
    {
     "pattern": "^[a-z0-9][a-z0-9-]{1,28}[a-z0-9]$"
    },
    {
     "pattern": "^(?!.*--)"
    }
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stableemail-b7c411fb/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)