Funding protocols determine how a card is provided with available balance and how the Immersve platform can settle or refund. A Funding Protocol is selected by specifying the Funding Type when creating a Funding Channel.
Protocol Variants
Three different variants classify immersve card funding protocols: deposit-based, approval-based, and custodial.
Approval Based Funding
Approval-based protocol variants utilize standard token approvals to enable spending stable coins on an Immersve card. Cardholders can spend assets directly from an existing wallet without an additional deposit transaction. The Universal EVM Funding Protocol supports approval-based funding on some EVM chains.
Deposit Based Funding
Deposit-based protocol variants require cardholders to transfer tokens into an Immersve smart contract. Deposits can be withdrawn at any time. Deposit-based funding is further classified into three sub-variants based on where tokens are deposited: universal, flexi and mock.
Universal Deposit — Cardholders deposit tokens into a shared partner-scoped smart contract. The universal deposit variant is optimized for gas usage so it can operate efficiently on any blockchain.
Flexi Deposit — Cardholders deposit tokens into a dedicated cardholder-scoped smart contract. The cardholder balance can be inspected on-chain, and permissionless withdrawals are supported. The cardholder contract must be deployed during cardholder onboarding.
Mock Deposit — Cardholder balance is set directly via API. It enables the creation of test cards without the need for asset deposits. Since no blockchain is involved, it enables testing of card-issuing user experiences when your preferred funding solution is not yet implemented. See Simulator Funding Protocol.
Custodial Funding
Custodial protocols enable the integrating partner to perform off-chain payment authorizations in real-time. Custodial funding leverages one of the on-chain deposit-based funding protocols for settlement. See Custodial Funding Protocol.
Available Chains
| Chain | Deposit Variant | Deposit Based Funding | Approval Based Funding | Custodial Billing |
|---|---|---|---|---|
| Algorand | flexi | ✅ | 🆇 | 🆇 |
| Arbitrum | universal | ✅ | ✅ | ✅ |
| Base | universal | ✅ | 🆇 | ✅ |
| Ethereum | universal | ✅ | 🆇 | 🆇 |
| Polygon | universal | ✅ | 🆇 | 🆇 |
Available Protocols
| Protocol | Description |
|---|---|
| Custodial Funding Protocol | Immersve's funding protocol that enables "custodial spend". Integrated client applications authorize Immersve card payments in real-time using their own ledger. |
| Algorand Funding Protocol | Immersve's funding protocol that operates on the Algorand blockchain. It uses "flexi" contract mechanics. Cardholder available balance can be inspected on-chain and permission-less withdrawal is supported. |
| Simulator Funding Protocol | Immersve's funding protocol that can be used for experimenting with Immersve card issuing without configuring on-chain components. |
| Universal EVM Funding Protocol | Immersve's funding protocol that can operate on any EVM chain. It uses "universal" contract mechanics and supports direct spend from a cardholder's existing wallet on some EVM chains. |