.. _how-to-start-chargelog:

How to Begin Charging
-------------------------------

To begin charging, you first need to select a charging station connection.
This can be done by fetching available charging stations through several
API calls (:ref:`How To Fetch Charging Stations <how-to-fetch-cps>`).
Choose a charging station connection and then verify via the
`availableCardsForChargingProcess`_ API call as long as the user has an
existing contract allowing them to begin charging using this connection.

Example request for `availableCardsForChargingProcess`_:

.. code-block:: javascript

    query availableCardsForChargingProcess {
      availableCardsForChargingProcess(
        connectorId: "ad7adac5-1111-2345-abcs-cc1c3115bd12"
      ) {
        id
        tagId
        number
        label
        expiryDate
        type
      }
    }


Example response for `availableCardsForChargingProcess`_:

.. code-block:: json

    {
      "data": {
        "availableCardsForChargingProcess": [
          {
            "id": "abc123",
            "tagId": "026347BA",
            "number": "abc123",
            "label": "xyz789"
          }
        ]
      }
    }

If there is a valid contract, this can now be used to begin charging via the
selected connection. See the `remoteStart`_ API call. If no contract exists,
the user may not yet have a contract
(:ref:`How To Create A Contract <how-to-create-authentication-media>`).
Once charging has successfully begun, a `RemoteStartResponse`_ data object
response will be received.

Example request to begin charging. You have to use the tagId from
`availableCardsForChargingProcess`_ as the authorization identifier:

.. code-block:: javascript

    mutation remoteStart {
      remoteStart(
        authorization: {
          identifier: "026347BA"
          type: AUTO
        },
        connector: "ad7adac5-1111-2345-abcs-cc1c3115bd12"
      ) {
      remoteStartResponse
    }

.. _availableCardsForChargingProcess: https://graphql.docs.htb.services/api-reference/#query-availableCardsForChargingProcess
.. _remoteStart: https://graphql.docs.htb.services/api-reference/#mutation-remoteStart
.. _RemoteStartResponse: https://graphql.docs.htb.services/api-reference/#definition-RemoteStartResponse