# number-recycling

```yaml
openapi: 3.0.3
info:
  title: Number Recycling
  description: |
    The API can be used to check whether the subscriber of the phone number has changed.
    A common scenario is when Application service provider (ASP) wants to check whether there has been a change in the user associated with the phone number after the specified date. This allows the ASP to ensure that a phone number is correctly linked to an user and prevent the mis-delivery of SMS messages.

    For example, below is a potential scenarios:
    * Scenario 1
      * Pre-conditions
        * User A signed a contract with MNO A for the phone number '+123456789' on October 9, 2023, and is still using it.
        * User A also signed contracts with ASP A on December 22, 2023 for its services.
        * ASP A holds the contract date (2023-12-22) and the phone number (+123456789) for User A.
        * Currently, on November 2, 2024, ASP A wishes to send a SMS message to User A.
      * Potential operations
        * ASP A sends a request with specified date (2023-12-22) and phone number (+123456789) to the Number Recycling API.
        * The API response sets to 'false', indicating that there has not been a change in the user associated with the phone number.
      * Post-conditions
        * ASP A decides to send the SMS message to User A.
      * By following these steps, ASP A ensures that a phone number is linked to User A.

    <img width="4000" alt="Number_Recycling_scenario_1" src="https://raw.githubusercontent.com/camaraproject/NumberRecycling/r1.1/documentation/API_documentation/assets/Number_Recycling_scenario_1.png">

    Note:
    * When API receives a request with specified date on which a user signed a contract with MNO, the API respond sets to 'false'(e.g., 2023-10-09 in the Scenario 1 of the figure above).

      * Scenario 2
        * Pre-conditions
          * User A signed a contract with MNO A for the phone number '+123456789' on October 9, 2023, and canceled it on February 25, 2024. Subsequently, User B signed a contract with MNO A for the same phone number on September 21, 2024, and is still using it.
          * User A also signed contracts with ASP A on December 22, 2023 for its services.
          * ASP A holds the contract date (2023-12-22) and the phone number (+123456789) for User A.
          * Currently, on November 2, 2024, ASP A wishes to send a SMS message to User A.
        * Potential operations
          * ASP A sends a request with specified date (2023-12-22) and phone number (+123456789) to the Number Recycling API.
          * The API response sets to 'true', indicating that there has been a change in the user associated with the phone number.
        * Post-conditions
          * ASP A decides to stop sending the SMS message to User A and contacts User A by mail.
        * By following these steps, ASP A ensures that a phone number is not linked to User A and prevents the mis-delivery of the SMS message.

    <img width="4000" alt="Number_Recycling_scenario_2" src="https://raw.githubusercontent.com/camaraproject/NumberRecycling/r1.1/documentation/API_documentation/assets/Number_Recycling_scenario_2.png">

    Note:
    * When the API receives a request with specified date during which there is no contract with MNO for the phone number, the API respond sets to 'true'(e.g., the period between 2024-02-25 and 2024-09-20 in the Scenario 2 of the figure above).

    # Authorization and authentication

    The "Camara Security and Interoperability Profile" provides details of how an API consumer requests an access token. Please refer to Identity and Consent Management (https://github.com/camaraproject/IdentityAndConsentManagement/) for the released version of the profile.

    The specific authorization flows to be used will be agreed upon during the onboarding process, happening between the API consumer and the API provider, taking into account the declared purpose for accessing the API, whilst also being subject to the prevailing legal framework dictated by local legislation.

    In cases where personal data is processed by the API and users can exercise their rights through mechanisms such as opt-in and/or opt-out, the use of three-legged access tokens is mandatory. This ensures that the API remains in compliance with privacy regulations, upholding the principles of transparency and user-centric privacy-by-design.

    # Identifying the phone number from the access token

    This API requires the API consumer to identify a phone number as the subject of the API as follows:
    - When the API is invoked using a two-legged access token, the subject will be identified from the optional `phoneNumber` field, which therefore MUST be provided.
    - When a three-legged access token is used however, this optional identifier MUST NOT be provided, as the subject will be uniquely identified from the access token.

    This approach simplifies API usage for API consumers using a three-legged access token to invoke the API by relying on the information that is associated with the access token and was identified during the authentication process.

    ## Error handling:

    - If the subject cannot be identified from the access token and the optional `phoneNumber` field is not included in the request, then the server will return an error with the `422 MISSING_IDENTIFIER` error code.
    - If the subject can be identified from the access token and the optional `phoneNumber` field is also included in the request, then the server will return an error with the `422 UNNECESSARY_IDENTIFIER` error code. This will be the case even if the same phone number is identified by these two methods, as the server is unable to make this comparison.

    ### Additional CAMARA error responses
    The list of error codes in this API specification is not exhaustive. Therefore the API specification may not document some non-mandatory error statuses as indicated in `CAMARA API Design Guide`.
    Please refer to the `CAMARA_common.yaml` of the Commonalities Release associated to this API version for a complete list of error responses. The applicable Commonalities Release can be identified in the `API Readiness Checklist` document associated to this API version.
    As a specific rule, error `501 - NOT_IMPLEMENTED` can be only a possible error response if it is explicitly documented in the API.

  version: wip
  x-camara-commonalities: tbd

  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0.html
externalDocs:
  description: Product documentation at CAMARA
  url: https://github.com/camaraproject/NumberRecycling
servers:
  - url: '{apiRoot}/number-recycling/vwip'
    variables:
      apiRoot:
        default: http://localhost:9091
        description: API root, defined by the service provider, e.g. `api.example.com` or `api.example.com/somepath`
paths:
  /check:
    post:
      security:
        - openId:
            - number-recycling:check
      tags:
        - Check Number Recycling
      summary: Check whether the subscriber of the phone number has changed.
      description: Check whether the subscriber of the phone number has changed.
      operationId: checkNumberRecycling
      parameters:
        - $ref: '#/components/parameters/x-correlator'
      requestBody:
        description: |
          Check whether the subscriber of the phone number has changed.
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CreateCheckNumRecycling'
        required: true
      responses:
        '200':
          description: OK
          headers:
            x-correlator:
              $ref: "#/components/headers/x-correlator"
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/CheckNumRecyclingInfo"
        '400':
          $ref: '#/components/responses/Generic400'
        '401':
          $ref: '#/components/responses/Generic401'
        '403':
          $ref: '#/components/responses/Generic403'
        '404':
          $ref: '#/components/responses/Generic404'
        '422':
          $ref: '#/components/responses/Generic422'
components:
  securitySchemes:
    openId:
      type: openIdConnect
      openIdConnectUrl: https://example.com/.well-known/openid-configuration
  parameters:
    x-correlator:
      name: x-correlator
      in: header
      description: Correlation id for the different services
      schema:
        $ref: "#/components/schemas/XCorrelator"
  headers:
    x-correlator:
      description: Correlation id for the different services
      schema:
        $ref: "#/components/schemas/XCorrelator"
  schemas:
    CreateCheckNumRecycling:
      type: object
      required:
        - specifiedDate
      properties:
        phoneNumber:
          $ref: '#/components/schemas/PhoneNumber'
        specifiedDate:
          type: string
          format: date
          description: Specified date to check whether there has been a change in the subscriber associated with the specific phone number, in RFC 3339 calendar date format (YYYY-MM-DD).
          example: "2024-10-31"
    PhoneNumber:
      description: A public identifier addressing a telephone subscription. In mobile networks it corresponds to the MSISDN (Mobile Station International Subscriber Directory Number). In order to be globally unique it has to be formatted in international format, according to E.164 standard, prefixed with '+'.
      type: string
      pattern: '^\+[1-9][0-9]{4,14}$'
      example: "+123456789"
    CheckNumRecyclingInfo:
      type: object
      required:
        - phoneNumberRecycled
      properties:
        phoneNumberRecycled:
          type: boolean
          description: |
            Set to true (Boolean, not string) when there has been a change in the subscriber associated with the specific phone number after “specifiedDate”.
    ErrorInfo:
      type: object
      required:
        - status
        - code
        - message
      properties:
        status:
          type: integer
          description: HTTP response status code
        code:
          type: string
          description: A human-readable code to describe the error
        message:
          type: string
          description: A human-readable description of what the event represents
    XCorrelator:
      type: string
      pattern: ^[a-zA-Z0-9-_:;.\/<>{}]{0,256}$
      example: "b4333c46-49c0-4f62-80d7-f0ef930f1c46"
  responses:
    Generic200:
      description: OK
      headers:
        x-correlator:
          $ref: '#/components/headers/x-correlator'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/CheckNumRecyclingInfo'

    Generic400:
      description: Problem with the client request
      headers:
        x-correlator:
          $ref: '#/components/headers/x-correlator'
      content:
        application/json:
          schema:
            allOf:
              - $ref: "#/components/schemas/ErrorInfo"
              - type: object
                properties:
                  status:
                    enum:
                      - 400
                  code:
                    enum:
                      - INVALID_ARGUMENT
                      - OUT_OF_RANGE
          examples:
            InvalidArgument:
              description: Invalid Argument. Generic Syntax Exception
              value:
                status: 400
                code: INVALID_ARGUMENT
                message: Client specified an invalid argument, request body or query param.
            OutOfRange:
              description: Out of Range. Specific Syntax Exception used when a given field has a pre-defined range or a invalid filter criteria combination is requested
              value:
                status: 400
                code: OUT_OF_RANGE
                message: Client specified an invalid range.

    Generic401:
      description: Authentication problem with the client request
      headers:
        x-correlator:
          $ref: '#/components/headers/x-correlator'
      content:
        application/json:
          schema:
            allOf:
              - $ref: "#/components/schemas/ErrorInfo"
              - type: object
                properties:
                  status:
                    enum:
                      - 401
                  code:
                    enum:
                      - UNAUTHENTICATED
          examples:
            Unauthenticated:
              description: Request cannot be authenticated and a new authentication is required
              value:
                status: 401
                code: UNAUTHENTICATED
                message: Request not authenticated due to missing, invalid, or expired credentials. A new authentication is required.

    Generic403:
      description: Client does not have sufficient permission
      headers:
        x-correlator:
          $ref: '#/components/headers/x-correlator'
      content:
        application/json:
          schema:
            allOf:
              - $ref: "#/components/schemas/ErrorInfo"
              - type: object
                properties:
                  status:
                    enum:
                      - 403
                  code:
                    enum:
                      - PERMISSION_DENIED
          examples:
            Permission Denied:
              description: Permission denied. OAuth2 token access not have the required scope or when the user fails operational security
              value:
                status: 403
                code: PERMISSION_DENIED
                message: Client does not have sufficient permissions to perform this action

    Generic404:
      description: Resource Not Found
      headers:
        x-correlator:
          $ref: '#/components/headers/x-correlator'
      content:
        application/json:
          schema:
            allOf:
              - $ref: "#/components/schemas/ErrorInfo"
              - type: object
                properties:
                  status:
                    enum:
                      - 404
                  code:
                    enum:
                      - IDENTIFIER_NOT_FOUND
          examples:
            Phone Number Used By Different Network Operator:
              description: Provided phone number is used by a different network operator
              value:
                status: 404
                code: IDENTIFIER_NOT_FOUND
                message: Phone number not found.

    Generic422:
      description: Unprocessable Content
      headers:
        x-correlator:
          $ref: '#/components/headers/x-correlator'
      content:
        application/json:
          schema:
            allOf:
              - $ref: "#/components/schemas/ErrorInfo"
              - type: object
                properties:
                  status:
                    enum:
                      - 422
                  code:
                    enum:
                      - SERVICE_NOT_APPLICABLE
                      - MISSING_IDENTIFIER
                      - UNNECESSARY_IDENTIFIER
          examples:
            Device Not Applicable:
              description: Service not applicable for the provided phone number
              value:
                status: 422
                code: SERVICE_NOT_APPLICABLE
                message: The service is not available for the provided phone number
            Unnecessary Identifier:
              description: An explicit identifier is provided when a phone number has already been identified from the access token
              value:
                status: 422
                code: UNNECESSARY_IDENTIFIER
                message: The phone number is already identified by the access token
            Missing Identifier:
              description: An identifier is not included in the request and the phone number identification cannot be derived from the 3-legged access token
              value:
                status: 422
                code: MISSING_IDENTIFIER
                message: The phone number cannot be identified
```