Fund the Card

Fund a card with collateral. Deposit on-chain for Rain-Managed programs, or fund your Rain account for Partner-Managed programs.

Rain cards are credit cards backed by collateral, so funding a card means adding collateral that backs the account. How you add it depends on your management model.

The credit-only model

A cardholder’s spending power equals the collateral backing their account. There is no stored prepaid balance: you deposit collateral to set a credit limit, and charges draw against that limit as the cardholder spends. Deposit more collateral to raise the limit.

How you hold that collateral depends on your management model. In Rain-Managed programs, each user has their own smart contract. In Partner-Managed programs, you hold collateral at the account level. See Flow of funds for the difference.

Fund a Rain-Managed program

In a Rain-Managed program, you deposit collateral into each user’s smart contract:

1. Get the user's contract address

   Call Get smart contract information to retrieve the deposit address, chain, and accepted tokens.

   const contracts = await client.users.retrieveContracts(userId);
   const contract = contracts[0];
   
   console.log(`Deposit to: ${contract.depositAddress}`);
   console.log(`Chain ID: ${contract.chainId}`);
   
2. Deposit supported tokens on-chain

   Send supported tokens, for example USDC, to the deposit address on the specified chain.

3. Confirm the credit limit

   The credit limit updates automatically within minutes. Check it with Get a user’s credit balances.

For admin access and collateral withdrawals, see Rain-Managed programs.

Fund a Partner-Managed program

In a Partner-Managed program, you hold collateral in your Rain account rather than per user. Add collateral from the dashboard with Add tokens, funding by wallet or Safe. Rain deploys a collateral contract per chain that serves as your reserve balance. As cardholders spend, charges post to your account, and you pay them off by ACH or crypto.

For payment options and balance management, see Partner-Managed programs.

Supported chains and tokens

Rain accepts USDC and USDT as collateral across supported chains, including Polygon, Base, Arbitrum, Optimism, Avalanche, Celo, BNB Smart Chain, ZKsync, Solana, Plasma, Monad, and Stellar. Token availability varies by chain. For the full matrix, chain IDs, and token contract addresses, see Supported chains and tokens.

In the sandbox, mint rUSD test tokens to simulate collateral. See Mint test tokens for collateral.

What’s next

Access card details

Decrypt a virtual card’s PAN and CVC on the client so the cardholder can start spending.

Test with simulations

Simulate card transactions and collateral funding in the sandbox.