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diff --git a/packages/taler-wallet-core/src/kyc.ts b/packages/taler-wallet-core/src/kyc.ts
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+++ b/packages/taler-wallet-core/src/kyc.ts
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+/*
+ This file is part of GNU Taler
+ (C) 2024 Taler Systems S.A.
+
+ GNU Taler is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+import {
+  AmountJson,
+  AmountLike,
+  Amounts,
+  AmountString,
+} from "@gnu-taler/taler-util";
+import { ReadyExchangeSummary } from "./exchanges.js";
+
+/**
+ * @fileoverview Helpers for KYC.
+ * @author Florian Dold <dold@taler.net>
+ */
+
+export interface SimpleLimitInfo {
+  kycHardLimit: AmountString | undefined;
+  kycSoftLimit: AmountString | undefined;
+}
+
+export interface MultiExchangeLimitInfo {
+  kycHardLimit: AmountString | undefined;
+  kycSoftLimit: AmountString | undefined;
+
+  /**
+   * Exchanges that would require soft KYC.
+   */
+  kycExchanges: string[];
+}
+
+/**
+ * Return the smallest given amount, where an undefined amount
+ * is interpreted the larger amount.
+ */
+function minDefAmount(
+  a: AmountLike | undefined,
+  b: AmountLike | undefined,
+): AmountJson {
+  if (a == null) {
+    if (b == null) {
+      throw Error();
+    }
+    return Amounts.jsonifyAmount(b);
+  }
+  if (b == null) {
+    if (a == null) {
+      throw Error();
+    }
+    return Amounts.jsonifyAmount(a);
+  }
+  return Amounts.min(a, b);
+}
+
+/**
+ * Add to an amount.
+ * Interprets the second argument as zero if not defined.
+ */
+function addDefAmount(a: AmountLike, b: AmountLike | undefined): AmountJson {
+  if (b == null) {
+    return Amounts.jsonifyAmount(a);
+  }
+  return Amounts.add(a, b).amount;
+}
+
+export function getDepositLimitInfo(
+  exchanges: ReadyExchangeSummary[],
+  instructedAmount: AmountLike,
+): MultiExchangeLimitInfo {
+  let kycHardLimit: AmountJson | undefined;
+  let kycSoftLimit: AmountJson | undefined;
+  let kycExchanges: string[] = [];
+
+  // FIXME: Summing up the limits doesn't really make a lot of sense,
+  // as the funds at each exchange are limited (by the coins in the wallet),
+  // and thus an exchange where we don't have coins but that has a high
+  // KYC limit can't meaningfully contribute to the whole limit.
+
+  for (const exchange of exchanges) {
+    const exchLim = getSingleExchangeDepositLimitInfo(
+      exchange,
+      instructedAmount,
+    );
+    if (exchLim.kycSoftLimit) {
+      kycExchanges.push(exchange.exchangeBaseUrl);
+      kycSoftLimit = addDefAmount(exchLim.kycSoftLimit, kycSoftLimit);
+    }
+    if (exchLim.kycHardLimit) {
+      kycHardLimit = addDefAmount(exchLim.kycHardLimit, kycHardLimit);
+    }
+  }
+
+  return {
+    kycHardLimit: kycHardLimit ? Amounts.stringify(kycHardLimit) : undefined,
+    kycSoftLimit: kycSoftLimit ? Amounts.stringify(kycSoftLimit) : undefined,
+    kycExchanges,
+  };
+}
+
+export function getSingleExchangeDepositLimitInfo(
+  exchange: ReadyExchangeSummary,
+  instructedAmount: AmountLike,
+): SimpleLimitInfo {
+  let kycHardLimit: AmountJson | undefined;
+  let kycSoftLimit: AmountJson | undefined;
+
+  for (let lim of exchange.hardLimits) {
+    switch (lim.operation_type) {
+      case "DEPOSIT":
+      case "AGGREGATE":
+        // FIXME: This should consider past deposits and KYC checks
+        kycHardLimit = minDefAmount(kycHardLimit, lim.threshold);
+        break;
+    }
+  }
+
+  for (let limAmount of exchange.walletBalanceLimitWithoutKyc ?? []) {
+    kycSoftLimit = minDefAmount(kycSoftLimit, limAmount);
+  }
+
+  for (let lim of exchange.zeroLimits) {
+    switch (lim.operation_type) {
+      case "DEPOSIT":
+      case "AGGREGATE":
+        kycSoftLimit = Amounts.zeroOfAmount(instructedAmount);
+        break;
+    }
+  }
+
+  return {
+    kycHardLimit: kycHardLimit ? Amounts.stringify(kycHardLimit) : undefined,
+    kycSoftLimit: kycSoftLimit ? Amounts.stringify(kycSoftLimit) : undefined,
+  };
+}
+
+export function getPeerCreditLimitInfo(
+  exchange: ReadyExchangeSummary,
+  instructedAmount: AmountLike,
+): SimpleLimitInfo {
+  let kycHardLimit: AmountJson | undefined;
+  let kycSoftLimit: AmountJson | undefined;
+
+  for (let lim of exchange.hardLimits) {
+    switch (lim.operation_type) {
+      case "BALANCE":
+      case "MERGE":
+        // FIXME: This should consider past merges and KYC checks
+        kycHardLimit = minDefAmount(kycHardLimit, lim.threshold);
+        break;
+    }
+  }
+
+  for (let limAmount of exchange.walletBalanceLimitWithoutKyc ?? []) {
+    kycSoftLimit = minDefAmount(kycSoftLimit, limAmount);
+  }
+
+  for (let lim of exchange.zeroLimits) {
+    switch (lim.operation_type) {
+      case "BALANCE":
+      case "MERGE":
+        kycSoftLimit = Amounts.zeroOfAmount(instructedAmount);
+        break;
+    }
+  }
+
+  return {
+    kycHardLimit: kycHardLimit ? Amounts.stringify(kycHardLimit) : undefined,
+    kycSoftLimit: kycSoftLimit ? Amounts.stringify(kycSoftLimit) : undefined,
+  };
+}
+
+export function checkWithdrawalHardLimitExceeded(
+  exchange: ReadyExchangeSummary,
+  instructedAmount: AmountLike,
+): boolean {
+  const limitInfo = getWithdrawalLimitInfo(exchange, instructedAmount);
+  return (
+    limitInfo.kycHardLimit != null &&
+    Amounts.cmp(limitInfo.kycHardLimit, instructedAmount) <= 0
+  );
+}
+
+export function checkPeerCreditHardLimitExceeded(
+  exchange: ReadyExchangeSummary,
+  instructedAmount: AmountLike,
+): boolean {
+  const limitInfo = getPeerCreditLimitInfo(exchange, instructedAmount);
+  return (
+    limitInfo.kycHardLimit != null &&
+    Amounts.cmp(limitInfo.kycHardLimit, instructedAmount) <= 0
+  );
+}
+
+export function checkDepositHardLimitExceeded(
+  exchanges: ReadyExchangeSummary[],
+  instructedAmount: AmountLike,
+): boolean {
+  const limitInfo = getDepositLimitInfo(exchanges, instructedAmount);
+  return (
+    limitInfo.kycHardLimit != null &&
+    Amounts.cmp(limitInfo.kycHardLimit, instructedAmount) <= 0
+  );
+}
+
+export function getWithdrawalLimitInfo(
+  exchange: ReadyExchangeSummary,
+  instructedAmount: AmountLike,
+): SimpleLimitInfo {
+  let kycHardLimit: AmountJson | undefined;
+  let kycSoftLimit: AmountJson | undefined;
+
+  for (let lim of exchange.hardLimits) {
+    switch (lim.operation_type) {
+      case "BALANCE":
+      case "WITHDRAW":
+        // FIXME: This should consider past withdrawals and KYC checks
+        kycHardLimit = minDefAmount(kycHardLimit, lim.threshold);
+        break;
+    }
+  }
+
+  for (let limAmount of exchange.walletBalanceLimitWithoutKyc ?? []) {
+    kycSoftLimit = minDefAmount(kycSoftLimit, limAmount);
+  }
+
+  for (let lim of exchange.zeroLimits) {
+    switch (lim.operation_type) {
+      case "BALANCE":
+      case "WITHDRAW":
+        kycSoftLimit = Amounts.zeroOfAmount(instructedAmount);
+        break;
+    }
+  }
+
+  return {
+    kycHardLimit: kycHardLimit ? Amounts.stringify(kycHardLimit) : undefined,
+    kycSoftLimit: kycSoftLimit ? Amounts.stringify(kycSoftLimit) : undefined,
+  };
+}