# Create Checkout

> Create a Stripe checkout link

**Endpoint:** `POST /v1/applications/{application_id}/checkout`  
**Access:** Account required (scope `billing:write`)  
**MCP tool:** `create_checkout`

Agents can create the link; only a person can pay. Payment is confirmed by webhook. Claims a guest draft first when needed.

## cURL example

```bash
curl -X POST "https://api.verifiedinbox.ai/v1/applications/0192a5e0-1234-7000-8000-000000000001/checkout" \
  -H "Authorization: Bearer vi_live_YOUR_API_KEY" \
  -H "Idempotency-Key: idem-$(date +%s)" \
  -H "Content-Type: application/json" \
  -d '{
    "product": "vmc"
  }'
```

## Parameters

| Parameter | Type | Description |
|---|---|---|
| `application_id` (path, required) | `string (uuid)` | Application id. |
| `Idempotency-Key` (header, required) | `string` | Unique key per intended action (≤ 255 chars). Same key + same body replays the first response; same key + different body → 409. |
| `VI-Environment` (header) | `string` | `live` (default) or `test`. Used for anonymous callers and OAuth access tokens; API keys and web sessions carry their own environment. |

## Request body

| Field | Type | Description |
|---|---|---|
| `product` | `string` | Defaults to the chosen/recommended product. |

```json
{
  "product": "vmc"
}
```

## Responses

### 201 OK

Checkout link.

```json
{
  "checkout_url": "https://verifiedinbox.ai/verify/0192a5e0-1234-7000-8000-000000000001/domain",
  "expires_at": "2026-10-31T12:00:00Z",
  "order_id": "0192a5e0-1234-7000-8000-000000000001",
  "reused": true
}
```

### 400 (invalid_request)

`invalid_request` — the request is malformed.

```json
{
  "error": {
    "code": "invalid_request",
    "message": "Please provide a valid domain name."
  }
}
```

### 401 (unauthenticated)

`unauthenticated` — sign in / send a valid credential. `next_action.kind = sign_in`.

```json
{
  "error": {
    "code": "unauthenticated",
    "message": "Sign in or provide an API key to continue.",
    "next_action": {
      "kind": "sign_in",
      "title": "Sign in or create an account",
      "url": "/login"
    }
  }
}
```

### 403 (insufficient_scope)

`forbidden` / `insufficient_scope` — the credential lacks permission.

```json
{
  "error": {
    "code": "insufficient_scope",
    "message": "This API key does not have the required scope for this action."
  }
}
```

### 404 (not_found)

`not_found` — doesn't exist or isn't accessible to you (never 403).

```json
{
  "error": {
    "code": "not_found",
    "message": "We couldn't find that resource."
  }
}
```

### 409 (version_conflict)

`conflict` / `version_conflict` (current state in `details.application`) / Idempotency-Key reuse.

```json
{
  "error": {
    "code": "version_conflict",
    "message": "This application was updated elsewhere. Refresh and try again."
  }
}
```

### 422 (unprocessable)

`unprocessable` / `blocked_provider` — understood but can't be done (plain-English reason).

```json
{
  "error": {
    "code": "unprocessable",
    "message": "Shared mailbox providers like gmail.com cannot be verified."
  }
}
```

### 429 (rate_limited)

`rate_limited` — retry after `Retry-After` seconds (`details.retry_after_seconds`). `limit_reached` — a quota is used up; `details.limit` names it and `next_action` offers support.

```json
{
  "error": {
    "code": "rate_limited",
    "message": "Too many requests. Please wait a moment and try again."
  }
}
```