---
title: "Open a Kismet-hosted preference confirmation"
description: "Prepares a confirmation URL valid for at most ten minutes, bound to this guest, installation, collection, registered website origin and disclosure. Open it as a standalone popup or tab. Do not collect consent in your own form. TEST simulates double opt-in with no real effects. LIVE independently records optional free membership and marketing choices; subscriptions remain pending until the guest confirms the code emailed to their verified address. Existing suppression is preserved."
---

`POST /v1/developer/guest/me/preferences/captures`

**Operation ID:** `prepareDeveloperGuestPreferenceCapture`

Prepares a confirmation URL valid for at most ten minutes, bound to this guest, installation, collection, registered website origin and disclosure. Open it as a standalone popup or tab. Do not collect consent in your own form. TEST simulates double opt-in with no real effects. LIVE independently records optional free membership and marketing choices; subscriptions remain pending until the guest confirms the code emailed to their verified address. Existing suppression is preserved.

## Contract status

| Field | Value |
| --- | --- |
| Maturity | `beta` |
| Required capability | `guest_preferences.write` |
| Freshness class | `authenticated-state` |
| Quota cost | `1` |

All operations require a Kismet Developer Bearer credential. Collection and resource authority is resolved from the credential's installation grants; identifiers in the URL never grant access.

## Request parameters

| Name | In | Type | Required | Description |
| --- | --- | --- | --- | --- |
| `x-kismet-guest-token` | header | string | yes | Verified guest access token held by your same-origin BFF, never browser JavaScript. |
| `x-kismet-csrf` | header | string | yes | CSRF proof validated by the same-origin BFF before forwarding. |

## Request body

The request body is JSON. The canonical schema is:

```json
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "parentOrigin"
  ],
  "properties": {
    "parentOrigin": {
      "type": "string",
      "minLength": 8,
      "maxLength": 255,
      "description": "Exact registered website origin; HTTPS except local development. Empty origin allowlists do not authorize capture."
    }
  }
}
```

Minimal example:

```json
{
  "parentOrigin": "string"
}
```

## cURL

Set `KISMET_API_ORIGIN=https://api.ksmt.app` and configure `KISMET_DEVELOPER_API_KEY` in your environment. Run server-credential requests from your backend, not browser code.

Guest access tokens come from the signed-in guest session held by your backend. Forward a CSRF proof only after your same-origin backend validates it. If shown, `KISMET_SITE_ORIGIN` is the authorized origin of your site. Do not substitute a guest ID or an invented token.

```sh
curl --request POST \
  "$KISMET_API_ORIGIN/v1/developer/guest/me/preferences/captures" \
  --header "Authorization: Bearer $KISMET_DEVELOPER_API_KEY" \
  --header "Accept: application/json" \
  --header "x-kismet-guest-token: $GUEST_ACCESS_TOKEN" \
  --header "x-kismet-csrf: $VALIDATED_CSRF_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{"parentOrigin":"string"}'
```

## Responses

| Status | Meaning |
| --- | --- |
| 200 | Success. |
| 400 | Invalid request parameters or body. |
| 401 | Missing, invalid, expired, or inappropriate credential/session. |
| 403 | Credential lacks the required grant/capability, or an origin/CSRF check failed. |
| 404 | The authorized resource was not found. |
| 409 | Request conflicts with the installation environment or current state. |
| 429 | Rate limit or quota exceeded; inspect response metadata before retrying. |
| 503 | A required Kismet dependency is temporarily unavailable. |

### 200 response schema

Content type: `application/json`. Required fields, nullable values, and nested structures are defined below.

<details>
<summary>View complete response schema</summary>

```json
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "captureId",
    "confirmationUrl",
    "expiresAt",
    "environment"
  ],
  "properties": {
    "captureId": {
      "type": "string",
      "format": "uuid"
    },
    "confirmationUrl": {
      "type": "string",
      "format": "uri"
    },
    "expiresAt": {
      "type": "string",
      "format": "date-time"
    },
    "environment": {
      "type": "string",
      "enum": [
        "TEST",
        "LIVE"
      ]
    }
  }
}
```

</details>

## Machine-readable sources

- [This page as Markdown](/api/reference/prepare-developer-guest-preference-capture.md)
- [Developer API OpenAPI v0.7.25](/openapi.json)