# Car constants

This endpoint returns localised car rental constants used across the Cars API collection, such as extras, fuel policies, payment timings, and transmission types.

It also returns customer service contact email addresses per requested language for partner support scenarios where Booking.com handles travellers' communication directly. 
To retrieve all constants, send an empty request body.

Endpoint: POST /cars/constants
Version: 3.2-Beta
Security: BearerAuth

## Header parameters:

  - `X-Affiliate-Id` (integer, required)
    Include here your Affiliate identifier number

## Request fields (application/json):

  - `constants` (array)
    Use this field to limit the response to specific categories, such as fuel_policies, depot_services, customer_services, etc. If omitted, all constants are returned.
    Enum: "car_categories", "customer_services", "depot_services", "depot_types", "extras", "special_offers", "fuel_policies", "fuel_types", "general", "payment_timings", "protection_levels", "review_scores", "transmission"

  - `languages` (array)
    List of language codes used to localise constant names. Each constant name is returned as a translated object keyed by language. If not provided, en-gb is used by default.
    Example: ["en-us"]

## Response 200 fields (application/json):

  - `request_id` (string)
    Uniquely identifies the request. Please provide this identifier when contacting support.

  - `data` (object)
    Contains constant groups keyed by constant type. Each group includes a list of constant identifiers and their translated names.

  - `data.car_categories` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.car_categories.id` (string)

  - `data.car_categories.name` (object)
    A string localised in multiple languages.

  - `data.car_categories.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.customer_services` (array)
    Customer service contact details per language. For each requested language, the API returns the corresponding customer support email address. English uses the default address, while other languages include a language-specific suffix.

  - `data.customer_services.id` (string)

  - `data.customer_services.name` (object)
    A string localised in multiple languages.

  - `data.customer_services.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.depot_services` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.depot_services.id` (string)

  - `data.depot_services.name` (object)
    A string localised in multiple languages.

  - `data.depot_services.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.depot_types` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.depot_types.id` (string)

  - `data.depot_types.name` (object)
    A string localised in multiple languages.

  - `data.depot_types.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.extras` (array)
    List of available extra products. Each item represents an optional add-on. Some extras may be bundled packages rather than individual items. For example, skierized_equipment refers to a winter sports package that typically includes a ski rack, ice scraper, and winter or all-season tyres.

  - `data.extras.id` (string)

  - `data.extras.name` (object)
    A string localised in multiple languages.

  - `data.extras.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.special_offers` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.special_offers.id` (string)

  - `data.special_offers.name` (object)
    A string localised in multiple languages.

  - `data.special_offers.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.fuel_policies` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.fuel_policies.id` (string)

  - `data.fuel_policies.name` (object)
    A string localised in multiple languages.

  - `data.fuel_policies.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.fuel_types` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.fuel_types.id` (string)

  - `data.fuel_types.name` (object)
    A string localised in multiple languages.

  - `data.fuel_types.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.general` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.general.id` (string)

  - `data.general.name` (object)
    A string localised in multiple languages.

  - `data.general.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.payment_timings` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.payment_timings.id` (string)

  - `data.payment_timings.name` (object)
    A string localised in multiple languages.

  - `data.payment_timings.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.protection_levels` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.protection_levels.id` (string)

  - `data.protection_levels.name` (object)
    A string localised in multiple languages.

  - `data.protection_levels.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.review_scores` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.review_scores.id` (string)

  - `data.review_scores.name` (object)
    A string localised in multiple languages.

  - `data.review_scores.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.

  - `data.transmission` (array)
    Represents a constant identifier and its translated display names for the requested languages.

  - `data.transmission.id` (string)

  - `data.transmission.name` (object)
    A string localised in multiple languages.

  - `data.transmission.name.^[a-z]{2}(-[a-z]{2})$` (string,null)
    The content localised in this language.