There are two models for the CaaS integration.

Merchant-of-Record (MoR) Model

Card Issuing

In the MoR Model, a single business entity is onboarded as the issuing party, with all issued cards linked to that entity. The entity can then assign these cards to different customers or individuals, who use the cards as their own.

Fund Flow

With the MoR model, the API client directly tops up their balance with Interlace. The funds flow is as follows:

When the client deposits fiat or crypto, the spending power they can allocate to cards equals the balance in their Quantum Account. The cardholders, who are the client’s end users, fund the client’s wallet independently of Interlace. The client retains custody of their own wallet and maintains an internal ledger to track each cardholder's spending limit.
This model operates as if the client deposits funds into the Interlace Reserve (e.g. the Interlace Quantum Account), which grants them credit to spend. As purchases are made, the Reserve balance decreases. To ensure sufficient spending power, the client must periodically transfer user-provided funds to the Interlace Reserve.
For example, if the client deposits 100k USDC into their Interlace Crypto Asset account and transfers it to the Quantum Account, they can assign up to $100k in total card limits. Meanwhile, their users deposit 150k USDC into their wallets. On the client’s internal ledger, users are assigned $150k in spending credit, exceeding the actual Reserve balance. In practice, this works because users are unlikely to spend the full amount at once. The client must, however, top up the Reserve as needed to maintain spending capability.

Gateway Model

Card Issuing

In the Gateway Model, a business entity (parent account) is onboard as the main issuer, with multiple sub-accounts (either individual or business) linked to it.

Fund Flow

In contrast to the MoR model, the API client does not directly hold user funds. Instead, Interlace’s sub-wallet infrastructure is used to receive user deposits. The funds flow is outlined below:

Interlace's crypto wallet infrastructure generates unique wallet addresses for each user to top up, ensuring their funds are securely held by Interlace. The client can access the balance of each sub-wallet through API queries, enabling them to maintain an accurate ledger of user transactions and spending.
To transfer funds to the Quantum Account, the client can utilize the sweep API, which consolidates funds from sub-wallets into the master wallet before transferring them to the Quantum Account.