openapi: 3.0.3
info:
title: Call Forwarding Signal Age Verification One Step Payment API
description: '# Overview
The Call Forwarding Signal API provides the API Consumer with
information about the status of the Call Forwarding Service on a specific
phone number. The main scope of the Call Forwarding Signal API is "anti
Fraud" to avoid fraudsters to use the Call Forwarding Service to carry
on a scam. Other use cases are anyway supported by the Call Forwarding
Signal API that also
provides additional endpoints to detect the general Call Forwarding
Service settings.
# Introduction
The Call Forwarding Service is provided by the Network to a phone
number. This service redirects the incoming call to that phone number
to an alternative destination such as another phone number or a voice mail
system. There are two main types of call forwarding settings:
unconditional and conditional.
The Call Forwarding Signal API can be invoked to detect if the unconditional
call forwarding service is active. The Call Forwarding Signal API can also
be invoked to
get the general status of the Call Forwarding Service (inactive,
conditional, unconditional). If conditional call forwarding is active,
the different type of settings are returned (''conditional_busy'',
''conditional_not_reachable'', ''conditional_no_answer'').
**Example use cases:**
[**Bank Frauds**](https://github.com/camaraproject/CallForwardingSignal/discussions/3#discussioncomment-8694420)
[**Alert Interception**](https://github.com/camaraproject/CallForwardingSignal/discussions/3#discussioncomment-8701847)
[**Call Forwarding Verification**](https://github.com/camaraproject/CallForwarding\Signal/discussions/3#discussioncomment-8915595)
# Quick Start
The Call Forwarding Signal API is a REST API based on the
CreateCallForwardingSignal resource.
This resource can be used, by the API Consumer, to specify the phone number
on which the Call Forwarding Service status must be verified, in case of
two-legged authentication. If three-legged authentication is used the phone
number is instead detected, by the API Producer, from the access token.
Before starting to use the Call Forwarding API, the developer needs to know
about the below specified details:
**phoneNumber**
This is the end user phone number. The Call Forwarding Signal API verifies
if a call forwarding
service is active on this phone number. Note: this parameter must be
must be provided/valued only in case of two-legged authentication.
In case of three-legged authentication the phone number is retrieved by
the access token.
**CreateCallForwardingSignal**
This is the resource the API Consumer uses to define the phone number to
be verified about the status of the Network Call Forwarding service.
**UnconditionalCallForwardingSignal**
This is the resource the API Consumer gets back, containing the information
about the Unconditional Call Forwarding Service status for the given phone
number (PhoneNumber).
**CallForwardingSignal**
This is the resource the API Consumer gets back, containing the information
about the general status of the Network Call Forwarding service for the
specified phone number.
The Call Forwarding Signal API provides two endpoints fulfilling the
following intents:
- **unconditional-call-forwardings**: Is the unconditional call fwd service
active on a specific phone number?
- **call-forwardings**: Which is the status of the call forwarding for a
specific phone number?
# API Documentation
## Details
The Call Forwarding Signal API is invoked by an API Consumer after the
Consent Management flow.
The API Consumer can request the API Producer for the status of the
Unconditional Call Forwarding service using the
unconditional-call-forwardings POST method. A boolean, with the information
about the activation status of the call forwarding service, will be
provided back via the UnconditionalCallForwardingSignal resource.
The API Consumer can also request the API Producer for the generic status of
the Call Forwarding service using the call-forwardings POST method. An array
of strings with the information of the type of active call forwarding
services will be provided back via the CallForwardingSignal resource.
# 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` object 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` object 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` object 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 device 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.
# FAQ''s
(FAQs will be added in a later version of the documentation)
'
version: wip
license:
name: Apache 2.0
url: https://www.apache.org/licenses/LICENSE-2.0.html
x-camara-commonalities: 0.6
servers:
- url: '{apiRoot}/call-forwarding-signal/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`
tags:
- name: One Step Payment
description: Operations to manage One Step Payment procedure
paths:
/payments:
post:
security:
- openId:
- carrier-billing:payments:create
tags:
- One Step Payment
summary: Create a new Payment
operationId: createPayment
description: Create a new payment for subsequent charging to an end user. Carrier Billing Server will apply the charging according to business configuration for the end user.
parameters:
- $ref: '#/components/parameters/x-correlator'
requestBody:
description: Amount transaction
content:
application/json:
schema:
$ref: '#/components/schemas/CreatePayment'
required: true
callbacks:
notifications:
'{$request.body#/sink}':
post:
security:
- {}
- notificationsBearerAuth: []
tags:
- Payment Notifications
summary: Carrier Billing payment notifications
operationId: createPaymentNotification
description: 'Important: This endpoint is exposed by the API client, accepting requests in the defined format.
The Carrier Billing server will call this endpoint whenever any carrier billing related event occurs.
'
parameters:
- $ref: '#/components/parameters/x-correlator'
requestBody:
description: Creates a new carrier billing payment notification
content:
application/cloudevents+json:
schema:
$ref: '#/components/schemas/CloudEvent'
required: true
responses:
'204':
description: Successful notification
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
'400':
$ref: '#/components/responses/Generic400'
'401':
$ref: '#/components/responses/Generic401'
'403':
$ref: '#/components/responses/Generic403'
'410':
$ref: '#/components/responses/Generic410'
'429':
$ref: '#/components/responses/Generic429'
responses:
'201':
description: Created
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
$ref: '#/components/schemas/PaymentCreated'
'400':
$ref: '#/components/responses/PaymentInvalid400'
'401':
$ref: '#/components/responses/Generic401'
'403':
$ref: '#/components/responses/PaymentPermissionDenied403'
'404':
$ref: '#/components/responses/IdentifierNotFound404'
'409':
$ref: '#/components/responses/Generic409'
'422':
$ref: '#/components/responses/PaymentUnprocessable422'
'429':
$ref: '#/components/responses/Generic429'
components:
schemas:
AmountTransaction:
required:
- phoneNumber
- paymentAmount
- referenceCode
type: object
properties:
phoneNumber:
type: string
description: 'Identifies the mobile account to be charged.
A public identifier addressing a telephone subscription. In mobile networks it corresponds to the MSISDN (Mobile Station International Subscriber Directory Number). In order to be globally unique it has to be formatted in international format, according to E.164 standard, prefixed with ''+''.'
pattern: ^\+[1-9][0-9]{4,14}$
example: '+34671999000'
clientCorrelator:
type: string
description: Uniquely identifies this create payment request. If there is a communication failure during the payment request, using the same clientCorrelator when retrying the request allows the operator to avoid applying the same charge twice. This field SHOULD be present. Same value as indicated in the request.
example: req-12f2pgh448gh2hvrfrv
paymentAmount:
$ref: '#/components/schemas/PaymentAmountForCharge'
referenceCode:
type: string
description: Merchant generated payment reference to uniquely identify the request, for instance, in the case of disputes. Same value as the one provided in the request.
example: ref-pay-834tfr2rA3v8r8vr3rv
resourceURL:
type: string
description: URI of the created resource (same as in the Location header)
example: urn:payments:AK234rfweSBuWGFUEWFGWEVWRV
serverReferenceCode:
type: string
description: Reference to the charge or refund, provided by the server, and meaningful to the server’s backend system for the purpose of reconciliation.
example: ref-pay-834tfr2rA3v8r8vr3rv-serv
PaymentCreated:
type: object
required:
- amountTransaction
- paymentId
- paymentStatus
- paymentCreationDate
properties:
paymentId:
type: string
description: Unique Identifier of the payment
example: AK234rfweSBuWGFUEWFGWEVWRV
amountTransaction:
$ref: '#/components/schemas/AmountTransaction'
paymentStatus:
type: string
description: Specifies the payment status (`processing`, `pending_validation`, `denied`, `reserved`, `succeeded`, `cancelled`).
example: processing
paymentCreationDate:
type: string
format: date-time
description: Date time when the payment is created in server database. This is a technical information. It must follow [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339#section-5.6) and must have time zone.
paymentDate:
type: string
format: date-time
description: Date time when the payment is effectively performed. This is a business information. It must follow [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339#section-5.6) and must have time zone.
sink:
type: string
format: uri
pattern: ^https:\/\/.+$
description: The address to which events shall be delivered, using the HTTP protocol.
example: https://endpoint.example.com/sink
CloudEvent:
description: The notification format
required:
- id
- source
- specversion
- type
- time
properties:
id:
type: string
description: Identifier of this event, that must be unique in the source context.
minLength: 1
example: sd5e-uy52-88t4-za66
source:
$ref: '#/components/schemas/Source'
type:
type: string
description: Type of event as defined in each CAMARA API
minLength: 25
example: org.camaraproject.carrier-billing.v0.payment-reserved
specversion:
type: string
description: Version of the specification to which this event conforms (must be 1.0 if it conforms to cloudevents 1.0.2 version)
minLength: 3
example: '1.0'
datacontenttype:
type: string
description: media-type that describes the event payload encoding, must be "application/json" for CAMARA APIs
example: application/json
data:
type: object
description: Event details payload described in each CAMARA API and referenced by its type
time:
$ref: '#/components/schemas/DateTime'
discriminator:
propertyName: type
mapping:
org.camaraproject.carrier-billing.v0.payment-pending-validation: '#/components/schemas/EventPaymentPendingValidation'
org.camaraproject.carrier-billing.v0.payment-reserved: '#/components/schemas/EventPaymentReserved'
org.camaraproject.carrier-billing.v0.payment-completed: '#/components/schemas/EventPaymentCompleted'
org.camaraproject.carrier-billing.v0.payment-cancelled: '#/components/schemas/EventPaymentCancelled'
org.camaraproject.carrier-billing.v0.payment-denied: '#/components/schemas/EventPaymentDenied'
ChargingInformation:
type: object
required:
- amount
- currency
- description
properties:
amount:
type: number
format: float
multipleOf: 0.001
minimum: 0.001
description: Amount to be charged or reserved.
example: 100
currency:
type: string
description: Currency code in which amount is expressed as defined in [ISO 4217](https://www.iso.org/iso-4217-currency-codes.html).
example: EUR
description:
type: string
description: Description text to be used for information and billing text
example: FIFA EA Sports 24
isTaxIncluded:
type: boolean
default: false
description: If true, the `amount` is tax included, if false the `amount` is provided without tax. In both cases, `taxAmount` could be indicated to provide tax amount.
taxAmount:
type: number
format: float
multipleOf: 0.001
minimum: 0
description: 'The tax amount charged by the merchant. Indicated when the merchant is the one applying taxes. This field also provides an indicator to the downstream billing system.
'
example: 21
AmountTransactionInput:
type: object
required:
- paymentAmount
- referenceCode
properties:
phoneNumber:
type: string
description: 'Identifies the mobile account to be charged.
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 ''+''.
Additional Considerations:
- Take a look to section `# Identifying the phone number from the access token` regarding the use of this field.'
pattern: ^\+[1-9][0-9]{4,14}$
example: '+34671999000'
clientCorrelator:
type: string
description: Uniquely identifies this create payment request. If there is a communication failure during the payment request, using the same clientCorrelator when retrying the request allows the operator to avoid applying the same charge twice. This field SHOULD be present.
example: req-12f2pgh448gh2hvrfrv
paymentAmount:
$ref: '#/components/schemas/PaymentAmountForCharge'
referenceCode:
type: string
description: Merchant generated payment reference to uniquely identify the request, for instance, in the case of disputes.
example: ref-pay-834tfr2rA3v8r8vr3rv
ChargingMetaData:
type: object
properties:
merchantName:
type: string
description: Indicates the merchant name. Allows aggregators/partners to specify the actual merchant name
example: EA Sports
merchantIdentifier:
type: string
description: Indicates the merchant identifier. Allows aggregators/partners to specify the actual merchant identifier
example: eas-12345
fee:
type: number
format: float
multipleOf: 0.01
description: Percentage of the amount to be received by the requester
example: 10
purchaseCategoryCode:
type: string
description: A category defining the type of service, product or media being purchased
example: games
channel:
type: string
description: The channel over which the requester is interacting with the merchant (e.g. WAP, Web, SMS...)
example: web
serviceId:
type: string
description: The identifier of the partner/merchant service being purchased
example: games-online
productId:
type: string
description: The product identifier to be combined with the `serviceId` to uniquely identify the product being purchased. For example if the `serviceId` relates to a VOD service, the `productId` can specify the movie rented
example: '138235321'
XCorrelator:
type: string
pattern: ^[a-zA-Z0-9-_:;.\/<>{}]{0,256}$
example: b4333c46-49c0-4f62-80d7-f0ef930f1c46
Source:
type: string
format: uri-reference
minLength: 1
description: "Identifies the context in which an event happened - be a non-empty `URI-reference` like:\n- URI with a DNS authority:\n * https://github.com/cloudevents\n * mailto:cncf-wg-serverless@lists.cncf.io\n- Universally-unique URN with a UUID:\n * urn:uuid:6e8bc430-9c3a-11d9-9669-0800200c9a66\n- Application-specific identifier:\n * /cloudevents/spec/pull/123\n * 1-555-123-4567"
example: https://notificationSendServer12.supertelco.com
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
SinkCredential:
type: object
properties:
credentialType:
type: string
enum:
- PLAIN
- ACCESSTOKEN
- REFRESHTOKEN
description: The type of the credential. Only `ACCESSTOKEN` is supported so far.
discriminator:
propertyName: credentialType
mapping:
PLAIN: '#/components/schemas/PlainCredential'
ACCESSTOKEN: '#/components/schemas/AccessTokenCredential'
REFRESHTOKEN: '#/components/schemas/RefreshTokenCredential'
required:
- credentialType
DateTime:
type: string
format: date-time
description: Timestamp when the occurrence happened. It must follow [RFC 3339](https://datatracker.ietf.org/doc/html/rfc3339#section-5.6) and must have time zone.
example: '2023-11-03T12:27:10Z'
CreatePayment:
type: object
required:
- amountTransaction
properties:
amountTransaction:
$ref: '#/components/schemas/AmountTransactionInput'
sink:
type: string
format: uri
pattern: ^https:\/\/.+$
description: The address to which events shall be delivered, using the HTTP protocol.
example: https://endpoint.example.com/sink
sinkCredential:
allOf:
- description: A sink credential provides authentication or authorization information necessary to enable delivery of events to a target.
- $ref: '#/components/schemas/SinkCredential'
PaymentItem:
type: object
required:
- id
- amount
- currency
- description
properties:
id:
type: string
description: Unique payment item identifier. Relevant to uniquely identify an item within a given payment when `paymentDetails` are provided and also to correlate information when a refund regarding this item is performed, by means of using `refundDetails`.
example: 3goug3uvu32v3b
amount:
type: number
format: float
multipleOf: 0.001
minimum: 0.001
description: Specific amount to be charged or reserved referred to a specific item.
example: 100
currency:
type: string
description: Currency code in which amount is expressed as defined in [ISO 4217](https://www.iso.org/iso-4217-currency-codes.html).
example: EUR
description:
type: string
description: Description text to be used for information and billing text referred to a specific item.
example: FIFA EA Sports 24
isTaxIncluded:
type: boolean
default: false
description: If true, the `amount` is tax included, if false the `amount` is provided without tax. In both cases, `taxAmount` could be indicated to provide tax amount.
taxAmount:
type: number
format: float
multipleOf: 0.001
minimum: 0
description: 'The tax amount charged by the merchant. Indicated when the merchant is the one applying taxes. This field also provides an indicator to the downstream billing system.
'
example: 21
PaymentDetails:
type: array
description: Detailed description of the concepts/items considered within a specific payment procedure.
minItems: 1
items:
$ref: '#/components/schemas/PaymentItem'
PaymentAmountForCharge:
type: object
required:
- chargingInformation
properties:
chargingInformation:
$ref: '#/components/schemas/ChargingInformation'
chargingMetaData:
$ref: '#/components/schemas/ChargingMetaData'
paymentDetails:
$ref: '#/components/schemas/PaymentDetails'
parameters:
x-correlator:
name: x-correlator
in: header
description: Correlation id for the different services
schema:
$ref: '#/components/schemas/XCorrelator'
responses:
PaymentInvalid400:
description: "Invalid input.\nCommon INVALID_ARGUMENT scenarios usually are:\n - Schema validation failed (\"code\": \"INVALID_ARGUMENT\",\"message\": \"Client specified an invalid argument, request body or query param.\").\n - Currency is unknown or not authorized (\"code\": \"INVALID_ARGUMENT\",\"message\": \"Currency is unknown or not authorized\").\n - clientCorrelator still exist (\"code\": \"INVALID_ARGUMENT\",\"message\": \"clientCorrelator already exist on server\").\n\nIn addition to regular INVALID_ARGUMENT scenario other scenarios may exist:\n - Invalid sink credential (\"code\": \"INVALID_CREDENTIAL\",\"message\": \"Only Access token is supported\").\n - Invalid sink credential access token (\"code\": \"INVALID_TOKEN\",\"message\": \"Only bearer token is supported\").\n - Invalid sink (\"code\": \"INVALID_SINK\",\"message\": \"sink not valid for the specified protocol\")."
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
- INVALID_CREDENTIAL
- INVALID_TOKEN
- INVALID_SINK
examples:
GENERIC_400_INVALID_ARGUMENT:
summary: Generic Invalid Argument
description: Invalid Argument. Generic Syntax Exception
value:
status: 400
code: INVALID_ARGUMENT
message: Client specified an invalid argument, request body or query param.
GENERIC_400_WRONG_CURRENCY:
summary: Generic Wrong Currency
description: Currency is unknown or not authorized
value:
code: INVALID_ARGUMENT
status: 400
message: Currency is unknown or not authorized.
GENERIC_400_DUPLICATE_CLIENT_CORRELATOR:
summary: Generic Duplicate Client Correlator
description: clientCorrelator still exist
value:
code: INVALID_ARGUMENT
status: 400
message: clientCorrelator already exist on server.
GENERIC_400_INVALID_CREDENTIAL:
summary: Generic Invalid Credential
description: Invalid sink credential
value:
status: 400
code: INVALID_CREDENTIAL
message: Only Access token is supported
GENERIC_400_INVALID_TOKEN:
summary: Generic Invalid Token
description: Invalid sink credential access token
value:
status: 400
code: INVALID_TOKEN
message: Only bearer token is supported
GENERIC_400_INVALID_SINK:
summary: Generic Invalid Sink
description: Invalid sink value
value:
status: 400
code: INVALID_SINK
message: sink not valid for the specified protocol
IdentifierNotFound404:
description: Phone Number 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:
GENERIC_404_IDENTIFIER_NOT_FOUND:
description: Some identifier cannot be matched to a device. In this API it refers to a phoneNumber.
value:
status: 404
code: IDENTIFIER_NOT_FOUND
message: phoneNumber not found.
PaymentPermissionDenied403:
description: "Client does not have sufficient permission.\nIn addition to regular PERMISSION_DENIED scenario other scenarios may exist:\n - Payment denied by business (\"code\": \"CARRIER_BILLING.PAYMENT_DENIED\",\"message\": \"Payment denied by business.\")."
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
- CARRIER_BILLING.PAYMENT_DENIED
examples:
GENERIC_403_PERMISSION_DENIED:
description: Permission denied. OAuth2 token access does 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.
GENERIC_403_PAYMENT_DENIED:
summary: Generic Payment Denied
description: Payment denied by business
value:
status: 403
code: CARRIER_BILLING.PAYMENT_DENIED
message: Payment denied by business.
Generic410:
description: Gone
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 410
code:
enum:
- GONE
examples:
GENERIC_410_GONE:
summary: Generic Gone
description: Use in notifications flow to allow API Consumer to indicate that its callback is no longer available
value:
status: 410
code: GONE
message: Access to the target resource is no longer available.
Generic429:
description: Too Many Requests
headers:
x-correlator:
$ref: '#/components/headers/x-correlator'
content:
application/json:
schema:
allOf:
- $ref: '#/components/schemas/ErrorInfo'
- type: object
properties:
status:
enum:
- 429
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# Full source: https://raw.githubusercontent.com/api-evangelist/camara-project/refs/heads/main/openapi/camara-project-one-step-payment-api-openapi.yml