Partial repayment & withdrawal [DEMO]

crates/contracts/src/programs/lending/scanners.rs

@@ -641,9 +641,14 @@ fn repayment_vault_deltas(
     debt_before: u64,
     amount_to_repay: u64,
 ) -> Option<(u64, u64)> {
-    let protocol_fee_repaid = params
+    let debt_after = debt_before.checked_sub(amount_to_repay)?;
+    let protocol_fee_before = params
         .offer_parameters
-        .get_repaid_protocol_fee(debt_before, amount_to_repay);
+        .get_already_repaid_protocol_fee(debt_before);
+    let protocol_fee_after = params
+        .offer_parameters
+        .get_already_repaid_protocol_fee(debt_after);
+    let protocol_fee_repaid = protocol_fee_after.checked_sub(protocol_fee_before)?;
     let lender_delta = amount_to_repay.checked_sub(protocol_fee_repaid)?;
 
     Some((lender_delta, protocol_fee_repaid))
@@ -1028,6 +1033,60 @@ mod tests {
         assert_eq!(scan.debt_after, debt_after);
     }
 
+    // Protocol fee must accrue cumulatively (floor(20*0.1) - floor(15*0.1) = 1), not per
+    // installment (floor(5*0.1) = 0), or a second fee-phase repayment goes unrecognized.
+    #[test]
+    fn discover_partial_repayment_second_fee_installment() {
+        let params = test_params();
+        let total = params.offer_parameters.get_total_amount_to_repay();
+        // First repayment of 15 already applied: fee repaid so far = 15, protocol fee = 1.
+        let debt_before = total - 15;
+        let active = LendingOffer::new_active(params, debt_before);
+        let amount_to_repay = 5_u64;
+        let debt_after = debt_before - amount_to_repay;
+        let continuing = LendingOffer::new_active(params, debt_after);
+
+        let lender_before = 14_u64;
+        let protocol_before = 1_u64;
+        // Correct, cumulative expectation: protocol fee goes 1 -> 2, lender absorbs the rest.
+        let protocol_after_supplied = 2_u64;
+        let lender_after_supplied = lender_before + (amount_to_repay - 1);
+
+        let lender_after = AssetAuthVault::new_active(
+            params.get_lender_vault_parameters(),
+            lender_after_supplied,
+        );
+        let protocol_after = AssetAuthVault::new_active(
+            params.get_protocol_fee_vault_parameters(),
+            protocol_after_supplied,
+        );
+
+        let tx = tx_with_outputs(vec![
+            explicit_output(params.borrower_nft_asset_id, 1, script(&[0x51])),
+            explicit_output(
+                params.collateral_asset_id,
+                3_000 - params.offer_parameters.get_collateral_for_principal(15 + 5),
+                continuing.get_script_pubkey(),
+            ),
+            explicit_output(
+                params.principal_asset_id,
+                lender_after_supplied,
+                lender_after.get_script_pubkey(),
+            ),
+            explicit_output(
+                params.principal_asset_id,
+                protocol_after_supplied,
+                protocol_after.get_script_pubkey(),
+            ),
+        ]);
+
+        let scan = active
+            .discover_partial_repayment(&tx, 0, 0, Some((lender_before, Some(protocol_before))))
+            .expect("second fee-phase repayment");
+        assert_eq!(scan.amount_to_repay, amount_to_repay);
+        assert_eq!(scan.debt_after, debt_after);
+    }
+
     #[test]
     fn scan_full_repayment_no_repayments_phase() {
         let params = test_params();

crates/indexer/configuration/base.yaml

@@ -13,6 +13,6 @@ esplora:
 indexer:
   protocol_fee_keeper_asset_id: '38fca2d939696061a8f76d4e6b5eecd54e3b4221c846f24a6b279e79952850a5'
   interval: 10000
-  last_indexed_height: 2549435
+  last_indexed_height: 2601330
   asset_registry:
     registry_url: 'https://assets-testnet.blockstream.info'

web/plugins/simplicitySourcesPlugin.ts

@@ -10,26 +10,40 @@ const SIMPLICITY_SOURCES_VIRTUAL = '\0virtual:simplicity-sources'
 const SIMPLICITY_SOURCES_ID = 'virtual:simplicity-sources'
 
 interface SimplicitySourcesPluginOptions {
-  // Path to the `contract_sources.json` map generated by
-  // `cargo run -p lending-contracts --example export_contract_sources`.
+  // Path to the `metadata.json` artifact generated by `simplex build` in crates/contracts
+  // (committed under crates/contracts/src/artifacts/metadata.json).
   sourcesPath: string
 }
 
+interface SimplicityMetadata {
+  sources: Record<string, { cmr: string; content: string }>
+}
+
+function toShortName(fileName: string): string {
+  return fileName.replace(/\.simf$/, '')
+}
+
 export function simplicitySourcesPlugin(options: SimplicitySourcesPluginOptions): Plugin {
   let viteConfig: ResolvedConfig
   let resolvedSourcesPath: string
 
   function readSources(): Record<string, string> {
     if (!fs.existsSync(resolvedSourcesPath)) {
       throw new Error(
-        `Simplicity contract sources not found: ${resolvedSourcesPath}\n` +
-          'Generate it with `cargo run -p lending-contracts --example export_contract_sources` in crates/contracts.',
+        `Simplicity contract metadata not found: ${resolvedSourcesPath}\n` +
+          'Generate it with `simplex build` in crates/contracts.',
       )
     }
 
     const raw = fs.readFileSync(resolvedSourcesPath, 'utf-8')
+    const metadata = JSON.parse(raw) as SimplicityMetadata
 
-    return JSON.parse(raw) as Record<string, string>
+    return Object.fromEntries(
+      Object.entries(metadata.sources).map(([fileName, { content }]) => [
+        toShortName(fileName),
+        content,
+      ]),
+    )
   }
 
   return {

web/src/api/indexer/utils.ts

@@ -21,7 +21,7 @@ export function resolvePendingOutpoint(offer: OfferDetails): string | null {
 }
 
 export function resolveActiveOutpoint(offer: OfferDetails): string | null {
-  const utxo = offer.utxos.find(u => u.utxo_type === 'active_offer')
+  const utxo = offer.utxos.find(u => u.utxo_type === 'active_offer' && u.spent_txid === null)
   return utxo ? toOutpoint(utxo) : null
 }
 
@@ -30,6 +30,16 @@ export function resolveLenderVaultOutpoint(offer: OfferDetails): string | null {
   return vault ? toOutpoint(vault) : null
 }
 
+export function resolveActiveLenderVaultOutpoint(offer: OfferDetails): string | null {
+  const vault = offer.vaults.find(v => v.vault_type === 'lender' && !v.is_finalized)
+  return vault ? toOutpoint(vault) : null
+}
+
+export function resolveActiveProtocolFeeVaultOutpoint(offer: OfferDetails): string | null {
+  const vault = offer.vaults.find(v => v.vault_type === 'protocol_fee' && !v.is_finalized)
+  return vault ? toOutpoint(vault) : null
+}
+
 export function resolveLenderNftOutpoint(offer: OfferDetails): string | null {
   const lender = offer.participants.find(p => p.participant_type === 'lender')
   return lender ? toOutpoint(lender) : null
@@ -39,3 +49,12 @@ export function resolveBorrowerNftOutpoint(offer: OfferDetails): string | null {
   const borrower = offer.participants.find(p => p.participant_type === 'borrower')
   return borrower ? toOutpoint(borrower) : null
 }
+
+export function resolveBorrowerPrincipalOutpoint(offer: OfferDetails): string | null {
+  return offer.borrower_principal_utxo ? toOutpoint(offer.borrower_principal_utxo) : null
+}
+
+export function resolveProtocolFeeVaultOutpoint(offer: OfferDetails): string | null {
+  const vault = offer.vaults.find(v => v.vault_type === 'protocol_fee' && v.is_finalized)
+  return vault ? toOutpoint(vault) : null
+}

web/src/components/modals/ClaimModal.tsx

@@ -67,6 +67,7 @@ export default function ClaimModal({ isOpen, offer, onClose, onSuccess }: ClaimM
       return claimLenderVault({
         lenderVaultOutpoint: vaultOutpoint,
         lenderNftOutpoint,
+        createOfferTxid: offer.created_at_txid,
         feeOutpoints: feeUtxos.map(utxoToOutpointString),
       })
     })

web/src/components/modals/LiquidateOfferModal.tsx

@@ -71,6 +71,7 @@ export default function LiquidateOfferModal({
         activeOfferOutpoint,
         createOfferTxid: offer.created_at_txid,
         lenderNftOutpoint,
+        currentDebt: fullOffer.current_debt.toString(),
         feeOutpoints: feeUtxos.map(utxoToOutpointString),
       })
     })

web/src/components/modals/RepayOfferModal.tsx

@@ -6,12 +6,17 @@ import { FALLBACK_FEE_RATE_SAT_PER_KVB, fetchFeeRateSatPerKvb } from '@/api/espl
 import { esploraQueryKeys } from '@/api/esplora/queryKeys'
 import { fetchOffer } from '@/api/indexer/methods'
 import type { OfferShort } from '@/api/indexer/schemas'
-import { resolveActiveOutpoint, resolveBorrowerNftOutpoint } from '@/api/indexer/utils'
+import {
+  resolveActiveLenderVaultOutpoint,
+  resolveActiveOutpoint,
+  resolveActiveProtocolFeeVaultOutpoint,
+  resolveBorrowerNftOutpoint,
+} from '@/api/indexer/utils'
 import OfferActionShell from '@/components/modals/OfferActionShell'
 import OfferDetailsBody from '@/components/modals/OfferDetailsBody'
 import { NETWORK_CONFIG } from '@/constants/network-config'
 import { useFormatAmount } from '@/hooks/useFormatAmount'
-import { useRepayOffer } from '@/hooks/useRepayOffer'
+import { usePartialRepayOffer } from '@/hooks/usePartialRepayOffer'
 import { useStandardTransactionFlow } from '@/hooks/useStandardTransactionFlow'
 import {
   estimateFeeBudgetSats,
@@ -45,7 +50,7 @@ export default function RepayOfferModal({
   const { principalAsset } = NETWORK_CONFIG
   const { syncWallet, getBlindedWalletUtxos, scriptPubkey, confirmedBalances } = useWallet()
   const { lwkNetwork } = useLwk()
-  const { repayOffer } = useRepayOffer()
+  const { partialRepayOffer } = usePartialRepayOffer()
   const runStandardTransactionFlow = useStandardTransactionFlow()
   const { addPendingTx } = usePendingTransactions()
   const { formatCollateralDisplay, formatPrincipalAmount } = useFormatAmount()
@@ -59,8 +64,9 @@ export default function RepayOfferModal({
       const borrowerNftOutpoint = resolveBorrowerNftOutpoint(fullOffer)
       if (!borrowerNftOutpoint) throw new Error('Borrower NFT UTXO not found')
 
-      const totalToRepay =
-        offer.principal_amount + calcInterest(offer.principal_amount, offer.interest_rate)
+      // current_debt already accounts for any prior partial repayment — repaying it in full here
+      // closes the loan the same way a single-shot repay on a fresh offer would.
+      const totalToRepay = fullOffer.current_debt
 
       await syncWallet()
       const [blindedWalletUtxos, feeRate] = await Promise.all([
@@ -83,9 +89,14 @@ export default function RepayOfferModal({
         feeRate,
       )
 
-      return repayOffer({
+      return partialRepayOffer({
         activeOfferOutpoint,
+        createOfferTxid: fullOffer.created_at_txid,
         borrowerNftOutpoint,
+        amountToRepay: totalToRepay.toString(),
+        currentDebt: totalToRepay.toString(),
+        lenderVaultOutpoint: resolveActiveLenderVaultOutpoint(fullOffer) ?? undefined,
+        protocolFeeVaultOutpoint: resolveActiveProtocolFeeVaultOutpoint(fullOffer) ?? undefined,
         principalOutpoints: principalUtxos.map(utxoToOutpointString),
         feeOutpoints: feeUtxos.map(utxoToOutpointString),
       })
@@ -105,8 +116,7 @@ export default function RepayOfferModal({
     },
   })
 
-  const totalToRepay =
-    offer.principal_amount + calcInterest(offer.principal_amount, offer.interest_rate)
+  const totalToRepay = offer.current_debt
   const { data: feeRate = FALLBACK_FEE_RATE_SAT_PER_KVB } = useQuery({
     queryKey: esploraQueryKeys.feeRate,
     queryFn: () => fetchFeeRateSatPerKvb(),

web/src/hooks/useCreateOffer.ts

@@ -345,13 +345,9 @@ export function useCreateOffer() {
             },
             scripts: {
               lendingScriptHash: bytesToHex(lendingScriptHash),
-              lenderVaultCovHash: bytesToHex(derivedLendingParams.lenderVaultCovHash),
-              finalizedLenderVaultCovHash: bytesToHex(
-                derivedLendingParams.finalizedLenderVaultCovHash,
-              ),
-              protocolFeeVaultCovHash: bytesToHex(derivedLendingParams.protocolFeeVaultCovHash),
-              finalizedProtocolFeeVaultCovHash: bytesToHex(
-                derivedLendingParams.finalizedProtocolFeeVaultCovHash,
+              lenderVaultTapleafHash: bytesToHex(derivedLendingParams.lenderVaultTapleafHash),
+              protocolFeeVaultTapleafHash: bytesToHex(
+                derivedLendingParams.protocolFeeVaultTapleafHash,
               ),
               principalOutputScriptHash: bytesToHex(derivedLendingParams.principalOutputScriptHash),
             },

web/src/hooks/useLenderVaultClaim.ts

@@ -31,10 +31,12 @@ import { usePendingTransactions } from '@/providers/pendingTransactions/usePendi
 import { useWallet } from '@/providers/wallet/useWallet'
 import {
   ASSET_AUTH_VAULT_MAX_WEIGHT_TO_SATISFY,
+  buildAssetAuthVaultSpendInfo,
   buildAssetAuthVaultWitness,
   loadAssetAuthVaultProgram,
 } from '@/simplicity/asset-auth-vault/program'
-import { buildCovenantSpendInfo } from '@/simplicity/taproot'
+import { findPendingOfferMetadata } from '@/simplicity/lending/metadata'
+import { getProtocolFee, getTotalAmountToRepay, getTotalFee } from '@/simplicity/lending/utils'
 import { bytesToHex } from '@/utils/hex'
 import { getProcessingTxids } from '@/utils/pendingTransactions'
 import { toBytes32, toUint32, toUint64 } from '@/utils/uint'
@@ -48,6 +50,7 @@ const LENDER_NFT_BURN_OUTPUT_INDEX = 0
 export interface LenderVaultClaimParams {
   lenderVaultOutpoint: string
   lenderNftOutpoint: string
+  createOfferTxid: string
   feeOutpoints: string[]
   principalRecipientAddress?: string
 }
@@ -89,9 +92,10 @@ export function useLenderVaultClaim() {
     if (feeUtxos.some(utxo => !isPolicyAssetUtxo(utxo, lwkNetwork.policyAsset()))) {
       throw new Error('Fee outpoints must be wallet L-BTC UTXOs')
     }
-    const [lenderVaultTx, lenderNftTx, feeTxs, feeRate] = await Promise.all([
+    const [lenderVaultTx, lenderNftTx, createOfferTx, feeTxs, feeRate] = await Promise.all([
       fetchTransaction(lenderVaultOutpoint),
       fetchTransaction(lenderNftOutpoint),
+      fetchTransaction(new OutPoint(`${params.createOfferTxid}:0`)),
       Promise.all(feeOutpoints.map(o => fetchTransaction(o))),
       fetchFeeRateSatPerKvbAbovePending(getProcessingTxids(pendingTxs)),
     ])
@@ -117,17 +121,28 @@ export function useLenderVaultClaim() {
     const lenderNftAsset = requireExplicitAsset(lenderNftTxOut, 'Lender NFT')
     const borrowerNftAsset = requireExplicitAsset(borrowerNftPreRepayTxOut, 'Borrower NFT')
     assertExplicitAmount(lenderNftTxOut, NFT_AMOUNT, 'Lender NFT')
+
+    const metadata = await findPendingOfferMetadata(createOfferTx)
+    const offerParameters = {
+      principalAmount: metadata.principalAmount,
+      principalInterestRate: metadata.principalInterestRate,
+    }
+    const lenderVaultSupplyGoal = toUint64(
+      getTotalAmountToRepay(offerParameters) - getProtocolFee(getTotalFee(offerParameters)),
+      'lenderVaultSupplyGoal',
+    )
     const lenderVaultProgram = loadAssetAuthVaultProgram({
       vaultAssetId: toBytes32(principalAsset.toBytes(), 'principalAssetId'),
       keeperAuthAssetId: toBytes32(lenderNftAsset.toBytes(), 'lenderNftAssetId'),
-      keeperAuthAssetAmount: toUint64(NFT_AMOUNT, 'lenderNftAmount'),
-      withKeeperAssetBurn: true,
       supplierAuthAssetId: toBytes32(borrowerNftAsset.toBytes(), 'borrowerNftAssetId'),
+      supplyGoal: lenderVaultSupplyGoal,
+      withKeeperAssetBurn: true,
       withSupplierAssetBurn: true,
-      finalizedVaultCovHash: toBytes32(new Uint8Array(32)),
+    })
+    const lenderVaultSpendInfo = buildAssetAuthVaultSpendInfo(lenderVaultProgram, {
       isActive: false,
+      alreadySupplied: lenderVaultSupplyGoal,
     })
-    const lenderVaultSpendInfo = buildCovenantSpendInfo(lenderVaultProgram)
 
     assertScriptMatches(
       lenderVaultTxOut.scriptPubkey(),