# Store a new preference for this user.

`POST /v1/preferences`

This endpoint creates a new preference. The name and data are free-format, and entirely up to you. If the preference is not used in Firefly III itself it may not be configurable through the user interface, but you can use this endpoint to persist custom data for your own app.

Authentication (security requirement alternatives):

```json
[
  {
    "firefly_iii_auth": []
  },
  {
    "local_bearer_auth": []
  }
]
```

- firefly_iii_auth: oauth2. OAuth2 authorization code flow. Create a client on your installation's `/profile` page; it authorizes at `/oauth/authorize` and issues tokens at `/oauth/token` there. The URLs below are the demo site's. [How to use the API](https://sourcey-firefly.pages.dev/how-to/firefly-iii/features/api/index.md) walks through it.
- local_bearer_auth: http (bearer). A Personal Access Token, sent as a bearer token. Create one on your installation under Options > Profile > OAuth > Personal Access Tokens.

Parameters:

- `X-Trace-Id` (header, string, uuid, optional) - Unique identifier associated with this request.
  Type: string, uuid
  
  Example:
  
  ```json
  "40c71bbb-c676-4f24-83cf-cc725d7d7a00"
  ```

Request body: application/json (required)

JSON array with the necessary preference information or key=value pairs. See the model for the exact specifications.

Type: object

Schema: [Preference](https://sourcey-firefly.pages.dev/api/models/preference/index.md)

- `created_at` (optional)
  Type: string, date-time
  
  readOnly: true
  
  Example:
  
  ```json
  "2026-10-01T00:00:00+00:00"
  ```

- `updated_at` (optional)
  Type: string, date-time
  
  readOnly: true
  
  Example:
  
  ```json
  "2026-10-01T00:00:00+00:00"
  ```

- `name` (required)
  Type: string, string
  
  Example:
  
  ```json
  "currencyPreference"
  ```

- `data` (required)
  Reference: [PolymorphicProperty](https://sourcey-firefly.pages.dev/api/models/polymorphicproperty/index.md); Type: PolymorphicProperty

Request body: application/x-www-form-urlencoded (required)

JSON array with the necessary preference information or key=value pairs. See the model for the exact specifications.

Type: object

Schema: [Preference](https://sourcey-firefly.pages.dev/api/models/preference/index.md)

- `created_at` (optional)
  Type: string, date-time
  
  readOnly: true
  
  Example:
  
  ```json
  "2026-10-01T00:00:00+00:00"
  ```

- `updated_at` (optional)
  Type: string, date-time
  
  readOnly: true
  
  Example:
  
  ```json
  "2026-10-01T00:00:00+00:00"
  ```

- `name` (required)
  Type: string, string
  
  Example:
  
  ```json
  "currencyPreference"
  ```

- `data` (required)
  Reference: [PolymorphicProperty](https://sourcey-firefly.pages.dev/api/models/polymorphicproperty/index.md); Type: PolymorphicProperty

Responses:

- 200: New account stored, result in response.

Content type: application/vnd.api+json

Type: object

Schema: [PreferenceSingle](https://sourcey-firefly.pages.dev/api/models/preferencesingle/index.md)

- `data` (required)
  Reference: [PreferenceRead](https://sourcey-firefly.pages.dev/api/models/preferenceread/index.md); Type: object

- 400: Bad request

Content type: application/json

Type: object

Schema: [BadRequestResponse](https://sourcey-firefly.pages.dev/api/models/badrequestresponse/index.md)

- `message` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "Bad Request"
  ```

- `exception` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "BadRequestHttpException"
  ```

- 401: Unauthenticated

Content type: application/json

Type: object

Schema: [UnauthenticatedResponse](https://sourcey-firefly.pages.dev/api/models/unauthenticatedresponse/index.md)

- `message` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "Unauthenticated"
  ```

- `exception` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "AuthenticationException"
  ```

- 404: Page not found

Content type: application/json

Type: object

Schema: [NotFoundResponse](https://sourcey-firefly.pages.dev/api/models/notfoundresponse/index.md)

- `message` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "Resource not found"
  ```

- `exception` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "NotFoundHttpException"
  ```

- 422: Validation error. The body will have the exact details.

Content type: application/json

Type: object

Schema: [ValidationErrorResponse](https://sourcey-firefly.pages.dev/api/models/validationerrorresponse/index.md)

- `message` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "The given data was invalid."
  ```

- `errors` (optional)
  Type: object
  
  - `email` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `force` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `blocked` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `field` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `role` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `blocked_code` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `name` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `type` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `iban` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `start` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `end` (optional)
    Type: array
    
    Items:
      Type: string, string
  
  - `date` (optional)
    Type: array
    
    Items:
      Type: string, string

- 500: Internal exception

Content type: application/json

Type: object

Schema: [InternalExceptionResponse](https://sourcey-firefly.pages.dev/api/models/internalexceptionresponse/index.md)

- `message` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "Internal Exception"
  ```

- `exception` (optional)
  Type: string, string
  
  Example:
  
  ```json
  "InternalException"
  ```

## Examples

### cURL

```bash
curl -X POST 'https://firefly.example.com/api/v1/preferences' \
  -H 'X-Trace-Id: 40c71bbb-c676-4f24-83cf-cc725d7d7a00' \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "name": "currencyPreference",
  "data": true
}'
```

### JavaScript

```javascript
const body = `{
  "name": "currencyPreference",
  "data": true
}`;

const response = await fetch('https://firefly.example.com/api/v1/preferences', {
  method: 'POST',
  headers: {
    'X-Trace-Id': '40c71bbb-c676-4f24-83cf-cc725d7d7a00',
    'Authorization': 'Bearer YOUR_TOKEN',
    'Content-Type': 'application/json',
  },
  body,
});

const data = await response.text();
```

### Python

```python
import requests

body = '''{
  "name": "currencyPreference",
  "data": true
}'''

response = requests.post(
    'https://firefly.example.com/api/v1/preferences',
    data=body.encode('utf-8'),
    headers={
        'X-Trace-Id': '40c71bbb-c676-4f24-83cf-cc725d7d7a00',
        'Authorization': 'Bearer YOUR_TOKEN',
        'Content-Type': 'application/json',
    },
)
print(response.text)
```