> ## Documentation Index
> Fetch the complete documentation index at: https://devzone.nayax.com/llms.txt
> Use this file to discover all available pages before exploring further.

# StopCallback

The `StopCallback` endpoint notifies the integrator that a consumer has
presented a payment card to stop an ongoing session.


## OpenAPI

````yaml /openapi/spark.yaml post /StopCallback
openapi: 3.0.1
info:
  title: Nayax Spark API
  description: RemoteStart V2
  version: v2
servers:
  - url: https://{domain}/api
    variables:
      domain:
        default: nayax-spark-dmz.nayax.com
        description: >-
          Your Nayax-assigned domain (e.g., nayax-spark-dmz.nayax.com). Nayax
          provides a QA domain during sandbox onboarding and a production domain
          after certification.
security: []
tags:
  - name: Transactions
paths:
  /StopCallback:
    post:
      tags:
        - Transactions
      summary: StopCallback
      requestBody:
        description: >-
          The request payload containing details of the card and session to be
          stopped.
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/StopCallbackRequest'
      responses:
        '200':
          description: Success. A simple 200 OK server acknowledgment is sufficient.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StopCallbackOutcome'
components:
  schemas:
    StopCallbackRequest:
      type: object
      nullable: true
      description: >
        The request payload sent by Spark to an integrator's configured
        `StopCallback` endpoint to notify that a consumer has presented a card
        to stop an ongoing session. This is used to validate and match the card
        against an active session.
      properties:
        StopSiteId:
          type: integer
          format: int16
          description: |
            The ID of the site where the session stop was triggered.
        MachineId:
          type: integer
          format: int64
          description: >
            The unique ID of the vending machine or device where the card was
            presented.
        HwSerial:
          type: string
          nullable: false
          description: |
            The hardware serial number of the terminal.
        CardLast4Digits:
          type: string
          nullable: true
          description: |
            The last four digits of the card used for the transaction.
        CardHash:
          type: string
          nullable: false
          description: |
            The hashed value of the payment card presented.
        SparkTransactionId:
          type: string
          nullable: true
          description: |
            The Spark transaction identifier of the original initiated session.
        NayaxTransactionId:
          type: integer
          nullable: true
          format: int64
          description: |
            The unique Nayax transaction ID associated with the open session.
        CardUid:
          type: string
          nullable: true
          description: |
            A unique identifier of the card, if available.
        MachineAuTime:
          type: string
          nullable: true
          description: |
            The terminal's local timestamp in the format `yyyyMMddHHmmssSSS`.
        ServiceStationNumber:
          type: string
          nullable: true
          description: |
            The identifier of the charging point or station used.
      example:
        StopSiteId: 4
        MachineId: 71234996
        HwSerial: '0434334921100366'
        CardLast4Digits: '1234'
        CardHash: 7f2082ba5dbccf706b6987e75b62083f65b5695bc2d8c827c3e46769d007a9e6
        SparkTransactionId: 12c7cec2-c690-4425-9a1f-db0db60e2d8c
        NayaxTransactionId: 2004545072
        CardUid: '1288528281124927'
        MachineAuTime: '20240205194122328'
        ServiceStationNumber: '5'
    StopCallbackOutcome:
      type: object
      nullable: true
      description: >
        The response payload from the integrator to Nayax's `StopCallback`,
        acknowledging the request and providing a status.
      properties:
        Status:
          $ref: '#/components/schemas/Status'
        SparkTransactionId:
          type: string
          nullable: true
          description: >
            The unique identifier for the Spark transaction that was requested
            to be stopped.
        ServiceStationNumber:
          type: string
          nullable: true
          description: >
            The number identifying the service station where the session stop
            was attempted. This value is provided by Nayax if the device is
            configured to support multiple service points.
      example:
        Status:
          Verdict: Approved
          ErrorDescription: No Errors
        SparkTransactionId: 12c7cec2-c690-4425-9a1f-db0db60e2d8c
        ServiceStationNumber: '5'
    Status:
      type: object
      nullable: false
      description: Transaction Status Details
      properties:
        Verdict:
          type: string
          nullable: false
          description: Status of the request (Approved / Declined)
        ErrorCode:
          type: integer
          format: int16
          nullable: true
          description: |
            - Conditional
            - Reason for declined request
        ErrorDescription:
          type: string
          nullable: true
          description: |
            - Conditional
            - Length: 255
            - Error description
        StatusMessage:
          type: string
          nullable: true
          description: |
            - Optional
            - Length: 255
            - Transaction status message as free text field

````