Walkthrough: Deposit & reserve collateral

This is the on-chain heart of the process. You’ll deposit collateral into your own self-custodial vault, then, once a lender is matched and contracts are signed, reserve it against your loan using a Letter of Credit (LoC).

You stay in control of the coins

The vault is yours. Helva never holds the coins. Reserving them for the loan does not transfer them to anyone. It locks the agreed amount under the rules in your contract. The conversion right is held for the lender. See The Letter of Credit.

Check every wallet prompt

Before you sign, use Verify your transactions. That page lists each field, and where to cross-check it. Do not rely on the app alone for addresses.

The steps

1. Approve the token (you’ll sign this in your wallet). The first time you deposit that asset, or when an older approval is smaller than this deposit, your wallet asks you to approve the Anvil Collateral Vault to spend the token. This is an on-chain transaction. You pay gas.

2. Deposit (you’ll sign this in your wallet). Confirm the deposit. Your collateral now sits in your Anvil vault.

3. Get matched and sign. A lender accepts your request. Helva generates the contracts (you, the lender, and Helva as broker and guarantor). The contracts are sent to you already pre-signed with a qualified electronic signature (QES) by Helva. Review and sign them.

4. Sign the allowance (you’ll sign this in your wallet). You authorize the Letter of Credit contract to reserve collateral from your vault. This is a signature, not a transaction, and you pay no gas. It is skipped if that allowance is already set.

5. Create the Letter of Credit (you’ll sign this in your wallet). This sends createDynamicLOC. Helva shows:

   • Amount: principal plus full-term interest, plus the FX buffer for a CHF loan.
   • Validity: loan maturity plus 5 days.
   • Beneficiary: Helva’s beneficiary contract, held for your lender. See Helva’s underlying entity.

   No one can convert more than the LoC amount, and unused collateral returns to you in kind.

If your vault is still short when you reserve, the wallet still asks for Approve, then Deposit, then Sign allowance, then Create LoC. Contract signing sits between the deposit and the Letter of Credit in the usual path.

New borrowers: deposit the minimum upfront

If you are a new borrower, it is recommended to deposit at least the minimum collateral for the maximum possible LTV before lenders see your request. Lenders can see whether you did, and some may choose not to accept loans from borrowers who haven’t. Existing borrowers with a track record can deposit later if they prefer.

When the amount you deposit covers the allowance the Letter of Credit needs, the app may send one transaction, depositAndApprove, that deposits and sets that allowance together. You will not see a separate Sign allowance step. The address being approved in that transaction must be Anvil’s Letter of Credit contract. The field list is on Verify your transactions.

The flow

sequenceDiagram
    autonumber
    actor B as You
    participant W as Your wallet
    participant A as Your Anvil vault
    participant H as Helva

    B->>W: Approve the token
    W->>A: Deposit collateral
    Note over A: Coins stay in your vault
    H-->>B: Lender matched, contracts already QES-signed
    B->>H: Sign contracts
    B->>W: Sign allowance, no gas
    B->>W: Create the Letter of Credit
    Note over A,H: LoC created. Helva checks it on-chain before the loan is activated

Anvil protocol parameters

Loan-to-value and liquidation thresholds are set by the Anvil protocol, not by Helva. Typical values: ~56% initial / ~66% liquidation for ETH-based collateral, ~60% / ~71% for BTC-based. See Collateral, LTV & liquidation.

Next: Receiving your funds →