How it works

Every loan on Lendr is a MarketListing — a single struct that starts life the moment a borrower calls createListing and ends in exactly one of three terminal states. There is no partial state: a listing is always fully unfunded, fully funded, or fully settled.

The five states

The two paths a listing can take

open ──fillListing──▶ active ──repay────────────▶ repaid      (borrower keeps collateral)
open ──cancelListing─▶ cancelled                                 (never funded)
                        active ──claimCollateral──▶ defaulted    (lender keeps collateral, only after maturity)

open and active are the only non-terminal states. repaid, defaulted, and cancelled never transition further — a listing's id is not reused or refunded into a new state once it lands there.

What has to be true at each step

• A listing can only be filled once — fillListing requires status == open, and it flips straight to active. There is no partial fill and no order book depth per listing; size is exactly what the borrower asked for.
• The borrower cannot fill their own listing — fillListing reverts if the caller is the borrower.
• repay only works while active, and only the borrower can call it. It always transfers loanAmount + interestOwed(id) to the lender, in full — there is no partial repayment.
• claimCollateral only works while active, only the lender can call it, and only once now >= startTime + duration. Calling it a second early does nothing but revert; there is no way to claim before maturity, ever.
• cancelListing only works while open, and only the borrower can call it. Once a lender has filled a listing, cancellation is no longer possible — the only exits are repay or waiting for the lender to claimCollateral after maturity.

Next steps