# agmail Inbox 4-Hour Renewal (MPP)

> agmail Inbox 4-Hour Renewal (MPP) is a paid API for AI agents from agmail.shveik.dev, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-10).

Renews an existing agmail receive-only email inbox by 4 hours, paying via the Micropayment Protocol (MPP) in stablecoins.

## Facts

- Endpoint: POST https://agmail.shveik.dev/v1/mpp/inbox-4h-renew?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agmail-inbox-4-hour-renewal-mpp-50b9c0e9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rhI-pSGtJVI1pn12G9qtE

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 agmail-inbox-4-hour-renewal-mpp-50b9c0e9 -d '<json body>'
```

Example prompt: My agmail inbox ib_0123456789ab is about to expire — renew it for another 4 hours using MPP with my secret so my agent can keep receiving emails.

## When to prefer this

Use this endpoint specifically when you need to extend an existing agmail inbox by exactly 4 hours via the Micropayment Protocol (MPP) and you already have the inbox_id and secret. Prefer this over other agmail sibling endpoints when your agent is mid-task and the inbox is about to expire and you want to pay programmatically in USDC stablecoins without manual intervention. If you need a different duration or are creating a new inbox rather than renewing, use the appropriate sibling endpoint instead.

## Known failure modes

- Invalid or mismatched inbox_id and secret — returns an authentication or not-found error
- Inbox does not exist or has already permanently expired — returns a 404 or invalid-state error
- Payment settlement failure or insufficient stablecoin balance — renewal remains queued but may not apply
- Malformed inbox_id (not matching pattern ^ib_[0-9a-f]{12}$) — returns a validation error
- Network or service timeout — payment may have been processed but status unknown, requiring a GET poll

## How this service works

Receive-only email inboxes for AI agents, by the hour. Pay in stablecoins with x402 or MPP; one call returns the code or the link.

## Output

Returns a JSON object with the inbox_id, the plan ('4h'), a status of 'queued' indicating the extension will be applied after payment settles (about a minute), and a 'next' field with instructions on how to poll for confirmation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "secret": {
   "type": "string"
  },
  "inbox_id": {
   "type": "string",
   "pattern": "^ib_[0-9a-f]{12}$"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "next": "The extension is applied once the payment has settled (a minute or so); GET /v1/…",
  "plan": "4h",
  "status": "queued",
  "inbox_id": "ib_0123456789ab"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agmail-inbox-4-hour-renewal-mpp-50b9c0e9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agmail.shveik.dev](https://www.zero.xyz/host/agmail.shveik.dev/llms.txt)