API Reference

Car Details

A car detail is the vehicle record Ototo calculates against — catalog price, fuel type, emissions, and the technical data Belgian tax rules depend on. Store one per vehicle and reference it by ID from Calculate or Tax Matrix, or pass the same shape inline to Calculate without storing it first.

Retrieve a car detail

GET /CarDetails/{carDetailId}

GET https://api.ototo.be/v1/CarDetails/{carDetailId}?subscription-key=YOUR_KEY

Status	Meaning
`200`	The car detail object, in JSON
`401`	Subscription key missing, invalid, or inactive — see Authentication
`404`	No car detail exists for that ID
`500`	Something went wrong on the server. Retry later; contact Ototo if it persists.

Create a car detail

POST /CarDetails

POST https://api.ototo.be/v1/CarDetails?subscription-key=YOUR_KEY
Content-Type: application/json

Body: a car detail object (see below). Any id or ownerId you send is ignored — both are assigned by Ototo.

Status	Meaning
`201`	Created. A `Location` header points at the new resource.
`400`	The car detail object was invalid — the response describes why (missing or invalid data)
`401`	Subscription key missing, invalid, or inactive — see Authentication
`500`	Something went wrong on the server. Retry later; contact Ototo if it persists.

Update (or create) a car detail

PUT /CarDetails/{carDetailId}

PUT https://api.ototo.be/v1/CarDetails/{carDetailId}?subscription-key=YOUR_KEY
Content-Type: application/json

Body: a car detail object (see below). This call is idempotent — it upserts the record at carDetailId. As with create, any id or ownerId in the body is ignored.

Status	Meaning
`200`	Updated an existing car detail. A `Location` header points at the resource.
`201`	No car detail existed at that ID, so one was created. A `Location` header points at the new resource.
`400`	The car detail object was invalid — the response describes why
`401`	Subscription key missing, invalid, or inactive — see Authentication
`500`	Something went wrong on the server. Retry later; contact Ototo if it persists.

The car detail object

Field	Type	Required	Description
`id`	`guid`	ignored on write	Unique identifier. Assigned by Ototo, except that `PUT` uses the ID in the URL.
`ownerId`	`guid`	ignored on write	Owning account, assigned by Ototo
`name`	`string`	optional, recommended	Display name shown to end users
`internalName`	`string`	optional	An internal identifier of your own choosing
`catalogPrice`	`decimal`	required	Catalog price*
`firstRegistration`	`date`	optional	Date of first registration (`yyyy-MM-dd`). Required in practice for cars first registered after 2021-01-01, since `wltp` becomes mandatory from that date.
`fuel`	enum	required	See `FuelType` below
`euroStandard`	enum	required	See `EuroStandard` below
`kilowatt`	`decimal`	required	Engine power, in kW
`wltp`	`int`	conditionally required	WLTP CO₂ emissions. Mandatory for vehicles with `firstRegistration` on or after 2021-01-01.
`nedC2`	`int`	required	NEDC2 CO₂ emissions
`capacity`	`int`	conditionally required	Engine capacity in cc. Required when `fuel` is `Diesel`, `Petrol`, `LPG`, `NaturalGas`, `HydrogenPetrol`, `HybridPetrol`, `HybridDiesel`, `PluginHybridDiesel`, or `PluginHybridPetrol`.
`weight`	`int`	optional, recommended	Vehicle weight. Used to determine "valse hybrides" (false hybrids) and Wallonia road tax.
`batteryCapacity`	`decimal`	conditionally required	Hybrid battery capacity. Required when `fuel` is `PluginHybridDiesel` or `PluginHybridPetrol`; used to determine "valse hybrides".
`nedC2NonHybrid`	`int`	recommended for plug-in hybrids	NEDC2 emissions of the comparable non-hybrid version. Needed for "valse hybride" calculations when `fuel` is `PluginHybridDiesel` or `PluginHybridPetrol`.
`wltpNonHybrid`	`int`	recommended for plug-in hybrids	WLTP emissions of the comparable non-hybrid version. Same purpose as `nedC2NonHybrid`.
`isActive`	`bool`	optional, defaults to `true`	Leave as `true`. Reserved for future functionality.

* Ototo stores prices excluding VAT. If your subscription is configured to send prices including VAT, tell your Ototo contact — the API will divide by 1.21 before storing. Provide as much of the non-mandatory data as you can: fields that aren't required for today's calculations may be needed by calculators added later.

`FuelType`

Name	Value
`Diesel`	10
`Petrol`	20
`LPG`	25
`NaturalGas`	30
`PluginHybridDiesel`	40
`PluginHybridPetrol`	50
`HybridPetrol`	60
`HybridDiesel`	70
`Electric`	80
`HydrogenPetrol`	90
`Hydrogen`	100

`EuroStandard`

Name	Value
`NA`	0
`Euro0`	10
`Euro1`	20
`Euro2`	30
`Euro3`	40
`Euro3Filter`	45
`Euro4`	50
`Euro4Filter`	55
`Euro5`	60
`Euro6`	70
`Euro7`	80

Enum fields accept either their numeric value or their name as a JSON string, e.g. "fuel": 80 or "fuel": "Electric".

Example

Request — create a car detail

POST https://api.ototo.be/v1/CarDetails?subscription-key=YOUR_KEY
Content-Type: application/json

{
  "name": "Tesla Model 3",
  "internalName": "TESLA-M3-2026",
  "catalogPrice": 45000.00,
  "firstRegistration": "2026-01-15",
  "fuel": "Electric",
  "euroStandard": "NA",
  "kilowatt": 150.00,
  "wltp": 0,
  "nedC2": 0,
  "weight": 1750
}

Response — 201 Created

Location: https://api.ototo.be/v1/CarDetails/12345678-1234-1234-1234-123456789abc

Response — 200 OK (GET)

{
  "id": "12345678-1234-1234-1234-123456789abc",
  "ownerId": "d9dfcaea-561b-46db-8bd4-7edb2d77566d",
  "name": "Tesla Model 3",
  "internalName": "TESLA-M3-2026",
  "catalogPrice": 45000.00,
  "firstRegistration": "2026-01-15T00:00:00",
  "fuel": "Electric",
  "euroStandard": "NA",
  "kilowatt": 150.00,
  "wltp": 0,
  "nedC2": 0,
  "capacity": null,
  "weight": 1750,
  "batteryCapacity": null,
  "nedC2NonHybrid": null,
  "wltpNonHybrid": null,
  "isActive": true
}