Custodial Card Issuing Integration Guide

This guide details the steps to add Immersve card issuing capabilities into applications that have custody of user funds. It lists the API calls required to set up a partner, onboard users, and create and test a card, with card spending pre-funded through deposits to an on-chain contract.

If you do not have custody over your users' funds then the Web3 Wallet Card Issuing Integration Guide will provide a better starting point for your integration.

Before You Get Started

Verify Your Asset is Supported

Before you begin integrating ensure your chain and token combination is supported. See Supported Chains and Supported Tokens.

Select KYC Mode

Partner Conducted KYC is the recommended KYC mode for custodial apps that have already verified their users. If users have not already been verified then Immersve Conducted KYC can be used.

Provision Application Resources

Set Up Your Partner Account

Contact support to get your: Partner Account ID, Client Application, API Key(s) and Card Program ID. You will initially have credentials to integrate with the Immersve test environment. When you are ready to test a live integration you will also receive live credentials.

Implement Custodial Webhooks

You will need to implement all custodial webhooks described in the Custodial Funding Protocol guide.

Register a Funding Channel

You will need a funding channel per token and chain. See the partner setup instructions in the Custodial Funding Protocol guide.

Fund Your Custodial Funds Pool

You need to deposit funds that will be used to settle cardholder transactions.

Setup Environment

Install Dependencies

This guide uses bash, curl and jq for example API interactions.

Configure Variables

The following variables are referenced from the example bash scripts throughout this guide.

card_issuer_api_key="<your_card_issuer_api_key>"
card_issuer_api_secret="<your_card_issuer_api_secret>"
partner_account_id="<your_partner_account_id>"
card_program_id="<your_card_program_id>"
funding_channel_id="<your_funding_channel_id>"
imsv_api_host=test.immersve.com

Immersve Environments

The Immersve test environment allows you to interact with all Immersve APIs while utilizing testnet assets. Test payments are initiated using the Payment Simulator. Note that the XPay capability is not available in the test environment.

Resource identifiers are not shared between the live and test environments. Your Partner Account, Client Application, API Keys and Card Program will all be different in the live environment.

Per Cardholder Setup

Check Region Availability

You can avoid presenting the card onboarding journey if the user's region is not yet available. Call the Get Supported Regions endpoint to get the current list of available regions for your application. See Supported Regions for more details.

Create a Cardholder Account

Provision each cardholder with an account and save their ID. In the custodial case it is assumed that you have gained permission to act on the cardholders behalf. All cardholder resources on our platform will be fully owned by your app. Each request on a cardholder resource must specify the cardholder by referencing the cardholder ID in the x-account-id header as specified in the Authentication Guide.

cardholder_account_id=$(curl \
  -X POST "https://${imsv_api_host}/api/accounts" \
  -H "Content-Type: application/json" \
  -H "X-Api-Key: ${card_issuer_api_key}" \
  -H "X-Api-Secret: ${card_issuer_api_secret}" \
  --data '{
    "parentAccountId": "'${partner_account_id}'",
    "type": "cardholder",
    "name": "<e.g. Cardholder Account of Joe>"
  }' | jq -r .id)

Register Cardholder Funding Source

You must create a Funding Source for a cardholder. The funding source can be connected to multiple cards if desired. The custodial Funding Source will be parameterized with an externalId which will be used to identify the funding ledger address for all card authorizations.

funding_source_external_id=''

funding_source_id=$(curl -X POST "https://${imsv_api_host}/api/funding-sources" \
  -H "Content-Type: application/json" \
  -H "X-Api-Key: ${card_issuer_api_key}" \
  -H "X-Api-Secret: ${card_issuer_api_secret}" \
  -H "X-Account-Id: ${cardholder_account_id}" \
  --data '{
    "accountId": "'${cardholder_account_id}'",
    "externalId": "'${funding_source_external_id}'",
    "fundingChannelId": "'${funding_channel_id}'",
  }' | jq -r '.id')

Complete Cardholder Onboarding

The spending prerequisites endpoint can be used to check whether the KYC and contact details requirements for a cardholder have been satisfied.

curl -X POST "https://${imsv_api_host}/api/spending-prerequisites" \
  -H "Content-Type: application/json" \
  -H "X-Api-Key: ${card_issuer_api_key}" \
  -H "X-Api-Secret: ${card_issuer_api_secret}" \
  -H "X-Account-Id: ${cardholder_account_id}" \
  --data '{
    "cardProgramId": "'${card_program_id}'",
    "fundingSourceId": "'${funding_source_id}'",
    "spendableAmount": 100,
    "spendableCurrency": "USD",
    "kycType": "partner-conducted",
  }'

Note that "spendableAmount" is required but is ignored for the custodial funding protocol. Any non-zero placeholder amount can be used.

Complete KYC Prerequisite

KYC requirements need to be completed before a cardholder obtains a card. If your application has already captured user KYC details then you may be able to use Partner Conducted KYC. Otherwise, Immersve Conducted KYC should be used.

Supply Contact Details

Immersve requires users contact details (phone number and email) for the following reasons, this should be explained to customers:

• Adding cards to Apple/Google Pay wallets (X-Pay)

• Performing 3DS validation for online transactions

If a user doesn't provide contact details, they risk online transactions being rejected and might not be able to add cards to X-Pay wallets.

Before you share contact details with Immersve you must collect user consent via a checkbox. This can be done at the same time as KYC information sharing.

curl -X PATCH "https://${imsv_api_host}/api/accounts/${cardholder_account_id}/contact-details" \
  -H "Content-Type: application/json" \
  -H "X-Api-Key: ${card_issuer_api_key}" \
  -H "X-Api-Secret: ${card_issuer_api_secret}" \
  -H "X-Account-Id: ${cardholder_account_id}" \
  --data '{
    "email": {
      "emailAddress": "joe@cardholder.email"
    },
    "phone": {
      "phoneNumber": "+64123456789"
    }
  }'

Request a Card

The Create Card, Get Card, and Get Card Token endpoints are all involved in requesting a card. See Issue a Virtual Card for further information.

Create a Card

Post the funding source ID and your provided card program ID to the card orders endpoint and record the returned card ID.

card_id=$(curl -X POST "https://${imsv_api_host}/api/cards" \
  -H "Content-Type: application/json" \
  -H "X-Api-Key: ${card_issuer_api_key}" \
  -H "X-Api-Secret: ${card_issuer_api_secret}" \
  -H "X-Account-Id: ${cardholder_account_id}" \
  --data '{
    "cardProgramId": "'${card_program_id}'",
    "fundingSourceId": "'${funding_source_id}'"
  }' | jq -r .cardId)

Get Card Details

Call Get Card Details to see card status and ensure it is active.

curl -X GET "https://${imsv_api_host}/api/cards/${card_id}" \
  -H "X-Api-Key: ${card_issuer_api_key}" \
  -H "X-Api-Secret: ${card_issuer_api_secret}" \
  -H "X-Account-Id: ${cardholder_account_id}"

Get Sensitive Card Details

Card sensitive details are obtained by generating a unique time-limited token. The response contains a callback URL which can be used to obtain the sensitive card details. See Fetching Secure Card Information for more details.

curl -X POST "https://${imsv_api_host}/api/cards/${card_id}/pan-token" \
  -H "X-Api-Key: ${card_issuer_api_key}" \
  -H "X-Api-Secret: ${card_issuer_api_secret}" \
  -H "X-Account-Id: ${cardholder_account_id}"

Perform a Test Card Payment

Perform a card payment using the Immersve Payment Simulator. Call the simulator endpoint with the sensitive card details.

curl -X POST "https://${imsv_api_host}/api/simulator/authorize" \
  -H "X-Api-Key: ${card_issuer_api_key}" \
  -H "X-Api-Secret: ${card_issuer_api_secret}" \
  -H "X-Account-Id: ${cardholder_account_id}"
  --data '{
    "transactionType": "purchase",
    "transactionAmount": "10",
    "cardPan": "1234567812345678",
    "cardExpiry": "202510",
    "cardCvv": "123"
  }'