# Your APIs for us
We can send following information to your API endpoints:
- 3DS OTP code, so you can handle delivery to the user yourself via SMS, Push or other channel.
- Notification about outcome of KYC process.
- Transaction request, so you can keep users balance on your end and accept or reject transactions their transactions (we call this "External Balance").
- Simple notification about transactions.
To make this work, you need to expose an API according to relevant section of this documentation.
To use external balance you must have Banking License or Payment Institution License. Additionally if you don't directly own BIN range, total sum of transactions of your users will be limited by deposit called "Master Balance".
### Security
To set secured server-server connection between our services Verestro requires a similar connection as in the case of client to Verestro communication based on the x509 certificate, more about this model [here](https://developer.verestro.com/books/connecting-to-our-services-and-sandbox/page/connecting-to-server-to-server-apis).
In the first step, Verestro will send to the client a CSR for the dev and production environments, more details [here](https://developer.verestro.com/books/connecting-to-our-services-and-sandbox/page/exposing-apis-for-us).
The next step is for the client to sign the CSR and send the certificate back to Verestro along with the base URL for the methods listed below. Verestro will authorize itself with each request with a certificate, which should be checked on the client side.
### Additional data encryption & integration
Some requests and responses contain sensitive data, to additionally secure the connection we require JSON Web Encryption (JWE).
### Idempotency Key
With some requests additional header X-Idempotency-Key could be send. This header contain unique random id allowing to identify single request.
If client send this header, operation should be triggered only once and for any further request with this key, response should be identical - in most cases, returned from cache.
**example headers:**
```
X-Idempotency-Key: 20e87975-dbfb-4c95-b239-169516c0b707
```
### JWE configuration
connection we need from you enc and alg from JWE parameters. Acceptable values are:
- Algorithm used by Verestro to encipher content of message (enc) - A256GCM,
- Algorithm used by Verestro to encipher encryption key (alg) - RSA-OAEP-256,
- Algorithm needed from you to encipher content of message (enc) - A256GCM,
- Allowed algorithms for key encryption (alg) - RSA-OAEP-256 or RSA-OAEP.
Recommended JWE libraries for various programming languages:
- [PHP](https://web-token.spomky-labs.com/),
- [JAVA](https://connect2id.com/products/nimbus-jose-jwt).
Request:
To process encrypted message you need to perform a few additional steps on top of standard message processing:
- Verestro add headlines:
- Public-Key through which you can encrypt response to us (if needed),
- Encrypted-Request headline confirming message encryption; value true or false,
- Expose endpoint with your Public Key - you will find a similar endpoint in our technical documentation, [GET /secure/public\_key](https://developer.verestro.com/books/card-management-system/page/technical-documentation-4Wl)
- Use Verestro Public Key to create JWE and transfer data in payload,
Response:
When the response contains sensitive data that requires encryption, use Verestro public key encryption available here [GET /secure/public\_key](https://developer.verestro.com/books/card-management-system/page/technical-documentation-4Wl)
Additional information:
- In case of errors (i.e. validation errors) you will receive unencrypted response,
- ENCRYPTION\_REQUIRED,
- INVALID\_PUBLIC\_KEY,
- INVALID\_PAYLOAD,
- CANT\_DECRYPT\_PAYLOAD.
Example request:
Example response:
#####
##### Public Key
This method is used to share your public key for encryption.
```
GET https://server-domain.com/public-key
```
**Headers:**
```
Content-Type: application/json
```
**response:**
```
200 OK
{
"publicKey": "QSBwdWJsaWMga2V5IHNob3VsZCBiZSBoZXJlIGhvd2V2ZXIgaXQgd2FzIHRvbyBsb25nIDoo"
}
```
### 3DS External OTP Notifier
This document describes API for external OTP notifier handling. Clients that are interested into having OTP notifier on their side must have implement this API to allow communication with Antaca to provide one time password about the transaction to client own users.
#### API 3DS External OTP Notifier
Below you will find a list of endpoints that you should implement on your server side. Please pay special attention to the appropriate security of our connection, the syntax of requests that you can expect from the Verestro side, idempotency and the exact way in which you should respond to each request.
These notifications support sending **[Idempotency Key](https://developer.verestro.com/books/card-management-system/page/your-apis-for-us#bkmrk-jwe-configuration)**
##### Notification OTP
This method is used to transfer a one-time password generated for transactions without a card present in the 3DS standard.
```
POST https://server-domain.com/notifications/otp
```
**Headers:**
```
Content-Type: application/json
X-Idempotency-Key: 20e87975-dbfb-4c95-b239-169516c0b707
```
**request body:**
```
{
"storageCustomerId" => "1337",
"storageCardId" => "1337",
"balanceId" => "b334b384-328c-11ed-a261-0242ac120002",
"amount" => "1000",
"currency" => "PLN",
"merchantName" => "merchant test",
"otp" => "1111"
}
```
**Parameters:**
**success response:**
```
204 No Content
```
**error responses:**
```
Code 422
{
"detail": "some specific details provided by server"
}
```
###
### External Verification Notifier
This document describes API for processed KYC verification notifier handling. Clients that are interested into having information about status KYC verification on their side must have implement this API to allow communication with Antaca.
Notifier provide notifications only with internal KYC status processes
These notifications support sending **[Idempotency Key](https://developer.verestro.com/books/card-management-system/page/your-apis-for-us#bkmrk-jwe-configuration)**
##### Notification verification In-progress
This method is used to transfer information about changed KYC verification status to 'IN\_PROGRESS'.
```
POST https://server-domain.com/notifications/verificationInProgress
```
**Headers:**
```
Content-Type: application/json
X-Idempotency-Key: 20e87975-dbfb-4c95-b239-169516c0b707
```
**request body:**
```JSON
{
"verificationId": "6faaa45a-41f6-4922-95fe-16e316ba7e91",
"userId": "1337",
"email": "leonbakiewicz@gmail.com",
"firstName": "Leon",
"lastName": "Bakiewicz",
"status": "IN_PROGRESS",
"reason": null,
}
```
**response:**
```
204 No Content
```
##### Notification verification accepted
This method is used to transfer information about changed KYC verification status to 'ACCEPTED'.
```
POST https://server-domain.com/notifications/verificationAccepted
```
**Headers:**
```
Content-Type: application/json
X-Idempotency-Key: 20e87975-dbfb-4c95-b239-169516c0b707
```
**request body:**
```JSON
{
"verificationId": "6faaa45a-41f6-4922-95fe-16e316ba7e91",
"userId": "1337",
"email": "leonbakiewicz@gmail.com",
"firstName": "Leon",
"lastName": "Bakiewicz",
"status": "ACCEPTED",
"reason": null,
}
```
**response:**
```
204 No Content
```
#####
##### Notification verification rejected
This method is used to transfer information about changed KYC verification status to 'REJECTED'.
```
POST https://server-domain.com/notifications/verificationRejected
```
**Headers:**
```
Content-Type: application/json
X-Idempotency-Key: 20e87975-dbfb-4c95-b239-169516c0b707
```
**request body:**
```JSON
{
"verificationId": "6faaa45a-41f6-4922-95fe-16e316ba7e91",
"userId": "1337",
"email": "leonbakiewicz@gmail.com",
"firstName": "Leon",
"lastName": "Bakiewicz",
"status": "REJECTED",
"reason": 'INVALID_CUSTOMER_DATA',
}
```
**response:**
```
204 No Content
```
**Parameters:**
**Sensitive data:**
This method is used to share your public key for encryption.
```
GET https://server-domain.com/public-key
```
**response:**
```
200 OK
{
"publicKey": "QSBwdWJsaWMga2V5IHNob3VsZCBiZSBoZXJlIGhvd2V2ZXIgaXQgd2FzIHRvbyBsb25nIDoo"
}
```
###
### External Balance
External Balance API is used, when client wishes to keep end users’ balances on their side. Thanks to this API, a client who maintains his clients accounts or has his own business logic affecting transaction authorizations has the opportunity to expand his offer with various payment instruments offered by Verestro, including payment cards, bank transfers, transfers to a telephone number and others. Workflow is reversed when using External Balance API - Antaca is sending request to server on client’s side.
#### Features
• linking (connecting) balance with customer in Antaca,
• getting list of balances,
• deleting balance link (connection),
• handling transactions,
• updating transaction status.
#### Purpose and scope
This guide provides an instruction and case study for using Extrnal Balance API. Document covers following topics:
• how to use External Balance API,
• transaction flow,
• how clearings are handled,
• use cases study.
#### Terminology
User - The end user for whom a balance is maintained along with the associated payment instruments.
Server - API exposed by Antaca’s client.
Client - company using Antaca services.
#### External Balance API
Below you will find a list of endpoints that you should implement on your server side. Please pay special attention to the appropriate security of our connection, the syntax of requests that you can expect from the Verestro side, idempotency and the exact way in which you should respond to each request.
##### Process of linking balances
After establishing secure connection, the client should create balance aliases for their users on the Antaca side. For identifiers created in this way, Antaca will be able to generate payment cards and process transactions. When the client creates a user on the Verestro side with confirmed KYC status and then orders the creation of a balance for him, this API will forward the request to link the balance to the user. The linking process is presented in the diagram below.
@startuml
skinparam ParticipantPadding 30
skinparam BoxPadding 30
skinparam noteFontColor #FFFFFF
skinparam noteBackgroundColor #1C1E3F
skinparam noteBorderColor #1C1E3F
skinparam noteBorderThickness 1
skinparam sequence {
ArrowColor #1C1E3F
ArrowFontColor #1C1E3F
ActorBorderColor #1C1E3F
ActorBackgroundColor #FFFFFF
ActorFontStyle bold
ParticipantBorderColor #1C1E3F
ParticipantBackgroundColor #1C1E3F
ParticipantFontColor #FFFFFF
ParticipantFontStyle bold
LifeLineBackgroundColor #1C1E3F
LifeLineBorderColor #1C1E3F
}
participant "Client server" as cs
participant Antaca as a
participant Lifecycle as lc
cs->lc: 1. create user by POST /wallet (firstName, lastName, phone, email)
lc-->cs: 2. userId
alt With own KYC process
cs->lc: 3. update KYC status by PUT /user (KYC)
else With Verestro KYC process
cs->a: 4. send KYC data by /register (user data with documents and selfie)
a->a: 5. process KYC
a->lc: 6. update KYC status
end
alt With automatic balance creation
lc-->a: 7. event about the new user with KYC
a->a: 8. create a balance in the default currency
a->cs: 10. link balance (userId, balanceId, currency)
cs-->a: 11. 204 (OK)
else Every time with create a balance
cs->a: 9. create balance by POST /balance (userId, currency)
a->cs: 10. link balance (userId, balanceId, currency)
cs-->a: 11. 204 (OK)
a-->cs: 12. 201 balance created
end
@enduml
Once balances are linked, Antaca can:
1. send a GET requests to retrieve information about specific balance. Using user ID and/or balance ID, Antaca can obtain information about balance currency and money amount.
2. send a GET requests to retrieve information about all user’s balances. Using only user ID Antaca can retrieve list of users balances.
3. delete link between balances
When user’s balance is equal to 0, it can be unlinked and deleted on Antaca side.
**Remember to avoid billing problems** Deleting a balance is only possible when its status is 0. This also applies to situations in which a user with at least one balance is deleted.
##### Transaction processing
When a balance is created and linked for a given user with verified KYC, from that moment the client-side API should be ready to accept transactions related to it. Depending on the payment instrument used, the data transferred in the transaction object may be different, but will always refer to a specific balance.
**Remember to avoid communication errors** Verestro servers attach an X-Idempotency-Key to each request in the header. This header contains a unique ID for each request to ensure idempotence. Each request with a unique identifier in this header should be processed only once on the client side and the response to it should be identical - in most cases, returned from cache
example:
```
curl POST "https://server-domain.com/transactions/debit"
--header "X-Idempotency-Key: 21aa0c2a-5554-4071-bd48-b9c64a0b6270"
```
##### Transaction object
Each transaction request contains following data:
```
{
"id": "b4f534ef-77c2-4f16-ab4d-496806a76fb6",
"balanceId": "b334b384-328c-11ed-a261-0242ac120002",
"resourceId": "9d673932-3291-11ed-a261-0242ac120002",
"resource": "card",
"transactionId": "ab3d89e4-3291-11ed-a261-0242ac120002",
"referenceTransactionId": "b759931c-3291-11ed-a261-0242ac120002",
"type": "POS",
"amount": 10000,
"currency": "PLN",
"originalAmount": 10000,
"originalCurrency": "PLN",
"status": "AUTHORIZED",
"description": "transaction description",
"date": "2020-08-17T18:43:42+00:00",
"transactionData": {
"mcc": "5942",
"merchantIdentifier": "003060300000005",
"merchantName": "Book store",
"captureMode": "NFC",
"lastFourDigits": "4560",
"acquirerCountry": "PL",
"mdesDigitizedWalletId": "Google Pay",
"cashbackPosCurrencyCode": "PLN",
"cashbackPosAmount": 10000,
"paymentTokenLastFourDigits": "7890",
"adjustmentReasonDescription": "REFUND",
"retrievalReferenceNumber": "749248185012"
}
}
```
**Parameters:**
| Parameter | Required | Description | Allowed values |
|---|
| id
| TRUE | Unique identifier of the transaction in UUID format
| any value in UUID v4 format, eg. ddb55ff9-11ca-4621-9129-81f939e66011
|
| balanceId
| TRUE | Unique user balance identifier | any string value (recommended uuid v4) |
| resourceId | TRUE | Unique resource identifier | any string value (recommended uuid v4) |
| resource
| TRUE | Name of a resource. | balance, card |
| transactionId
| TRUE | Transaction identifier obtained from card netwok or generated on client side using the method to generate transaction in Antaca.
**IMPORTANT: this id may not be unique - it is generated by different systems**
| any string value (recommended uuid v4) |
| referenceTransactionId
| FALSE | Id of previous transaction to witch current request relates | any string value (recommended uuid v4) |
| type
| TRUE | Type of transaction | cashback, loan, payment, topup, commission, fee, funding, interest, withdrawal, pos, atm, cashback\_at\_pos, adjustment |
| amount
| TRUE | Transaction value in gross (minor value) | integer value |
| currency
| TRUE | Currency 3-letters code in ISO 4217 | ISO 4217 3-letter code |
| originalAmount
| FALSE | Original transaction value in gross (minor value) | integer value |
| originalCurrency
| FALSE | Original currency 3-letters code in ISO 4217 | ISO 4217 3-letter code |
| status
| TRUE | Transaction status | AUTHORIZED, CLEARED, REVERSED |
| description
| TRUE | Transaction description | any string value |
| date
| TRUE | Date of transaction in UTC | date in UTC |
| transactionData | FALSE | Additional transaction data. This object presents detailed data depending on the transaction type | This object is described below |
**TransactionData data object:**
##### Integration with External Balance
By using external balance API, you take an active part in processes affecting settlements, therefore the API issued by you will be subject to approval before production starts. To make this process easier for you, below you will find a postman collection with test cases.
#### API External balance
Below you will find a list of endpoints that you should implement on your server side. Please pay special attention to the appropriate security of our connection, the syntax of requests that you can expect from the Verestro side, idempotency and the exact way in which you should respond to each request. If you decide to implement external balance to be able to keep the balance on your side and authorize transactions, remember that the implementation of all the methods below is required to ensure the API works.
##### Link balance
This method is used to link customer balance between client and server. Requested **balanceId** will be used for communication between client and Verestro side.
If you create balance entity at your end you should create it after receiving this call. Do not create balance entity on your side as result of POST /secure/balances nor POST /secure/customers/{id}/balances, because link balance will be called before response to these methods.
```
POST https://server-domain.com/users/:id/balances
```
**path parameters:**
id - user identifier
**Headers:**
```
Content-Type: application/json
Accept: application/json
```
**request body:**
```
{
"balanceId":"2e520dc2-329d-11ed-a261-0242ac120002",
"currency": "PLN"
}
```
**parameters:**
```
balanceId - unique identifier of balance. This id will be used in communication between client and server.
currency - required, should be 3 letters code in ISO 4217 https://www.iban.com/currency-codes
```
**response:**
```
204 NoContent
```
**error codes:** 404 - should be returned if no user has been matched by requested path parameter.
```
Code 404
{
"title": "USER_NOT_FOUND",
"detail": "some specific details provided by server"
}
```
##### Get single user balance
Method used to obtain single user balance information.
```
GET https://server-domain.com/users/:id/balances/:balanceId
```
**path parameters:**
```
id - user identifier
balanceId - unique balance identifier
```
**headers:**
```
Accept: application/json
```
**response:**
```
200 OK
{
"currency": "PLN",
"amount": 250
}
```
**response parameters:**
```
currency - three letter iso 4217 code
amount - actual balance amount in minor (penny), numeric value
```
**error codes:** 404 - should be returned if no balance found by requested balanceId.
```
Code 404
{
"title": "BALANCE_NOT_FOUND",
"detail": "some specific details provided by server"
}
```
403 - if requested balance does not belong to user.
```
Code 403
{
"title": "FORBIDDEN",
"detail": "some specific details provided by server"
}
```
##### Get balance collection
This method should return collection of customer balances.
```
GET https://server-domain.com/users/:id/balances
```
**path parameters:**
```
id - user identifier
```
**headers:**
```
Accept: application/json
```
**response:**
```
200 OK
[
{
"id": "a072bd0e-328c-11ed-a261-0242ac120001",
"currency": "PLN",
"amount": 250
},
{
"id": "b334a5e2-328c-11ed-a261-0242ac120002",
"currency": "USD",
"amount": 460
}
]
```
If user has not created any balance yet, there should be returned empty collection.
```
200 OK
[]
```
**response parameters:**
```
id - unique identifier of user balance
currency - three letter iso 4217 code
amount - actual balance amount in minor (penny), numeric value
```
##### Delete balance
This method is used to unattached balance from user. From legal point of view, balance should be deleted only if there is no money on it.
```
DELETE https://server-domain.com/users/:id/balances/:balanceId
```
**path parameters:**
```
id - user identifier
balanceId - unique balance identifier
```
**response:**
```
204 No Content
```
**error responses:**
404 - if requested balance has not been found.
```
Code 404
{
"title": "BALANCE_NOT_FOUND",
"detail": "some specific details provided by server"
}
```
403 - if requested balance does not belong to user.
```
Code 403
{
"title": "FORBIDDEN",
"detail": "some specific details provided by server"
}
```
##### Debit transaction
This kind of transaction is used to authorize transaction. In debit transactions Antaca asks 'if user has money?'.
```
POST https://server-domain.com/transactions/debit
```
**headers:**
```
Content-Type: application/json
X-Idempotency-Key: uuidV4
```
**request body:**
Description of the contents of the transaction object can be found above.
**success response:**
```
204 No Content
```
**error responses:**
```
422
{
"title": "INSUFFICIENT_FUNDS",
"detail": "some specific details provided by server"
}
```
```
422
{
"title": "LIMITS_EXCEEDED",
"detail": "some specific details provided by server"
}
```
```
422
{
"title": "FRAUDS_DETECTED",
"detail": "some specific details provided by server"
}
```
```
404
{
"title": "BALANCE_NOT_FOUND",
"detail": "some specific details provided by server"
}
```
##### Force debit transaction
This kind of transaction is used to inform server side that transaction has occurred.
For this request, actual transaction already happen so server can not reject this request. This behavior can occur for offline transactions fe: in plane, subway, for refunds and referring to previously authorized transactions.
```
POST https://server-domain.com/transactions/force-debit
```
**headers:**
```
Content-Type: application/json
X-Idempotency-Key: uuidV4
```
**request body:**
Description of the contents of the transaction object can be found above.
**response:**
```
204 No Content
```
**error response:**
As mention in description section, **we do not accept transaction rejection**.
##### Credit transaction
Method is used to credit user balance. In credit transactions Antaca asks 'can user get money?'.
```
POST https://server-domain.com/transactions/credit
```
**headers:**
```
Content-Type: application/json
X-Idempotency-Key: uuidV4
```
**request body:**
Description of the contents of the transaction object can be found above.
**success response:**
```
204 No Content
```
**error responses:**
```
404
{
"title": "BALANCE_NOT_FOUND",
"detail": "cannot find requested balance"
}
```
```
422
{
"title": "FRAUDS_DETECTED",
"detail": "some specific details provided by server"
}
```
##### Force credit
Method is used to credit user balance. This kind of transaction is used to inform server side that transaction has occurred. For this request, actual transaction already happen so server can not reject this request.
```
POST https://server-domain.com/transactions/force-credit
```
**headers:**
```
Content-Type: application/json
X-Idempotency-Key: uuidV4
```
**request body:**
Description of the contents of the transaction object can be found above.
**success response:**
```
204 No Content
```
**error response:**
As mention in description section, **we do not accept transaction rejection**.
##### Reversal
Method is used to revert any changes for previous transaction. Request body will be identical to transaction witch client try to revert. If server cannot find referenced transaction then no action is required.
```
POST https://server-domain.com/transactions/reversal
```
**headers:**
```
Content-Type: application/json
X-Idempotency-Key: uuidV4
```
**request body:**
Description of the contents of the transaction object can be found above.
**success response:**
```
204 No Content
```
**error responses:**
IMPORTANT: for this method, we do not accept any error. Only satisfying behavior is to revert referenced transaction and no action if cannot find transaction.
##### Update transaction status
From time to time, client will inform about clearings triggered by acquirer side. If client mark transaction as cleared it means that transaction will not be corrected by any other transaction request and requested amount is final.
```
PUT https://server-domain.com/transactions/:id
```
**path parameters:**
id - transaction identifier
**request body:**
Description of the contents of the transaction object can be found above.
**success response:**
```
204 No Content
```
**error responses:**
```
404
{
"title": "TRANSACTION_NOT_FOUND",
"detail": "cannot find requested transaction"
}
```
### Transactions notifier
To get notifications about transactions use [Transaction History Core API](https://developer.verestro.com/books/transaction-history-api/page/technical-documentation-thc-external-api)
##### Transaction Types Description
Debit transactions list:
| **Type**
| **Description**
|
| POS
| POS transaction (A point-of-sale) applies to the situation when a customer makes a purchase and the payment is processed through the POS system.
|
| ATM
| ATM Transaction is when the cardholder uses a physical card at an ATM to withdraw cash.
|
| Balance Inquiry | Check the available balance of funds.
|
| Commission
| internal transaction for a partner who wants to debit user balance as a commission referenced to the other transaction.
|
| Fee
| internal transaction for a partner who wants to debit user balance as a fee.
Antaca automatically **credits** company balance with the funds that were debit the user's balance
|
| Funding
| internal transaction type used to debit the user's balance. This type indicates that the funds still remain in the Antaca system, usually in conjunction with a payment type a credit transaction on the user's balance.
Antaca automatically **credit** the **credit partner balance** with this transaction
|
| Interest
| internal transaction for a partner who wants debit the user's balance as part of the interest connected with credit agreement.
|
| Withdrawal
| internal transaction type used to debit the user's balance. This type indicates that the funds go outside the Antaca system, fe: withdrawal from an account at a bank branch.
|
Credit transactions list:
| TopUp
| internal transaction type used to top up the user's balance. This type indicates that the funds come from outside the Antaca system, fe: payment to an account at a bank branch.
Antaca automatically **debit** the **credit partner balance** with this transaction
|
| Payment
| internal transaction type used to top up the user's balance. This type indicates that the funds come from the Antaca system, usually in conjunction with a funding type a debit transaction on the user's balance
Antaca automatically **debit** the **credit partner balance** with this transaction
|
| Loan
| internal transaction for a partner who wants to top up the user's balance as part of the credit agreement.
Antaca automatically **debit** the **credit partner balance** with this transaction
|
| CreditIbanTransfer
| internal transaction dedicated only for IMS API (via specific CN). IMS API uses this balance to credit funds on the user's balance.
|
| Cashback
| internal transaction for a partner who wants to top up the user's balance as part of the loyalty program
Antaca automatically **debit** the **credit partner balance** with this transaction
|