diff --git a/packages/taler-harness/src/harness/harness.ts b/packages/taler-harness/src/harness/harness.ts
index 7c54c0c47..bac691637 100644
--- a/packages/taler-harness/src/harness/harness.ts
+++ b/packages/taler-harness/src/harness/harness.ts
@@ -1825,6 +1825,7 @@ export class MerchantService implements MerchantServiceInterface {
     if (!this.proc) {
       throw Error("merchant must be running to add instance");
     }
+    console.trace("here!");
     logger.info("adding instance");
     const url = `http://localhost:${this.merchantConfig.httpPort}/management/instances`;
     const auth = instanceConfig.auth ?? { method: "external" };
diff --git a/packages/taler-harness/src/harness/libeufin-apis.ts b/packages/taler-harness/src/harness/libeufin-apis.ts
index 3c57eee07..0553223cb 100644
--- a/packages/taler-harness/src/harness/libeufin-apis.ts
+++ b/packages/taler-harness/src/harness/libeufin-apis.ts
@@ -176,7 +176,10 @@ export interface LibeufinSandboxAddIncomingRequest {
   direction: string;
 }
 
-const libeufinHttpLib = createPlatformHttpLib();
+const libeufinHarnessHttpLib = createPlatformHttpLib({
+  allowHttp: true,
+  enableThrottling: false,
+});
 
 /**
  * APIs spread across Legacy and Access, it is therefore
@@ -192,7 +195,7 @@ export namespace LibeufinSandboxApi {
     iban: string | null = null,
   ): Promise<void> {
     let url = new URL("testing/register", libeufinSandboxService.baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       body: {
         username: username,
@@ -211,7 +214,7 @@ export namespace LibeufinSandboxApi {
   ): Promise<void> {
     // baseUrl should already be pointed to one demobank.
     let url = new URL("ebics/subscribers", libeufinSandboxService.baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       body: {
         userID: req.userID,
@@ -228,7 +231,7 @@ export namespace LibeufinSandboxApi {
   ): Promise<void> {
     const baseUrl = libeufinSandboxService.baseUrl;
     let url = new URL(`admin/ebics/hosts/${hostID}/rotate-keys`, baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       body: {},
     });
@@ -239,7 +242,7 @@ export namespace LibeufinSandboxApi {
   ): Promise<void> {
     const baseUrl = libeufinSandboxService.baseUrl;
     let url = new URL("admin/ebics/hosts", baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       body: {
         hostID,
@@ -255,7 +258,7 @@ export namespace LibeufinSandboxApi {
   ): Promise<void> {
     const baseUrl = libeufinSandboxService.baseUrl;
     let url = new URL(`admin/bank-accounts/${req.label}`, baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       body: req,
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
@@ -272,7 +275,7 @@ export namespace LibeufinSandboxApi {
   ): Promise<void> {
     const baseUrl = libeufinSandboxService.baseUrl;
     let url = new URL("admin/ebics/subscribers", baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       body: req,
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
@@ -289,7 +292,7 @@ export namespace LibeufinSandboxApi {
   ): Promise<void> {
     const baseUrl = libeufinSandboxService.baseUrl;
     let url = new URL("admin/ebics/bank-accounts", baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       body: req,
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
@@ -306,7 +309,7 @@ export namespace LibeufinSandboxApi {
       `admin/bank-accounts/${accountLabel}/simulate-incoming-transaction`,
       baseUrl,
     );
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       body: req,
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
@@ -322,7 +325,7 @@ export namespace LibeufinSandboxApi {
       `admin/bank-accounts/${accountLabel}/transactions`,
       baseUrl,
     );
-    const res = await libeufinHttpLib.fetch(url.href, {
+    const res = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return (await res.json()) as SandboxAccountTransactions;
@@ -334,7 +337,7 @@ export namespace LibeufinSandboxApi {
   ): Promise<any> {
     const baseUrl = libeufinSandboxService.baseUrl;
     let url = new URL("admin/payments/camt", baseUrl);
-    return await libeufinHttpLib.fetch(url.href, {
+    return await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {
@@ -350,7 +353,7 @@ export namespace LibeufinSandboxApi {
   ): Promise<LibeufinSandboxAdminBankAccountBalance> {
     const baseUrl = libeufinSandboxService.baseUrl;
     let url = new URL(`admin/bank-accounts/${accountLabel}`, baseUrl);
-    const res = await libeufinHttpLib.fetch(url.href, {
+    const res = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return res.json();
@@ -362,7 +365,7 @@ export namespace LibeufinNexusApi {
     nexus: LibeufinNexusServiceInterface,
   ): Promise<NexusBankConnections> {
     let url = new URL("bank-connections", nexus.baseUrl);
-    const res = await libeufinHttpLib.fetch(url.href, {
+    const res = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return res.json();
@@ -374,7 +377,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL("bank-connections/delete-connection", baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: req,
@@ -387,7 +390,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL("bank-connections", baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {
@@ -411,7 +414,7 @@ export namespace LibeufinNexusApi {
   ): Promise<any> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`bank-accounts/${accountName}`, baseUrl);
-    const resp = await libeufinHttpLib.fetch(url.href, {
+    const resp = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return resp.json();
@@ -427,7 +430,7 @@ export namespace LibeufinNexusApi {
       `bank-accounts/${accountName}/payment-initiations/${paymentId}/submit`,
       baseUrl,
     );
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {},
@@ -443,7 +446,7 @@ export namespace LibeufinNexusApi {
       `bank-connections/${connectionName}/fetch-accounts`,
       baseUrl,
     );
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {},
@@ -461,7 +464,7 @@ export namespace LibeufinNexusApi {
       `bank-connections/${connectionName}/import-account`,
       baseUrl,
     );
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {
@@ -477,7 +480,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`bank-connections/${connectionName}/connect`, baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {},
@@ -495,7 +498,7 @@ export namespace LibeufinNexusApi {
       `/bank-accounts/${accountName}/payment-initiations`,
       baseUrl,
     );
-    let response = await libeufinHttpLib.fetch(url.href, {
+    let response = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     const respJson = await response.json();
@@ -518,7 +521,7 @@ export namespace LibeufinNexusApi {
     for (const [k, v] of Object.entries(params)) {
       url.searchParams.set(k, String(v));
     }
-    let response = await libeufinHttpLib.fetch(url.href, {
+    let response = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return response.json();
@@ -534,7 +537,7 @@ export namespace LibeufinNexusApi {
   ): Promise<LibeufinNexusTransactions> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`/bank-accounts/${accountName}/transactions`, baseUrl);
-    let response = await libeufinHttpLib.fetch(url.href, {
+    let response = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return response.json();
@@ -553,7 +556,7 @@ export namespace LibeufinNexusApi {
       `/bank-accounts/${accountName}/fetch-transactions`,
       baseUrl,
     );
-    const resp = await libeufinHttpLib.fetch(url.href, {
+    const resp = await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {
@@ -572,7 +575,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`/users/${username}/password`, baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: req,
@@ -585,7 +588,7 @@ export namespace LibeufinNexusApi {
   ): Promise<NexusUserResponse> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`/user`, baseUrl);
-    const resp = await libeufinHttpLib.fetch(url.href, {
+    const resp = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return resp.json();
@@ -597,7 +600,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`/users`, baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: req,
@@ -609,7 +612,7 @@ export namespace LibeufinNexusApi {
   ): Promise<NexusGetPermissionsResponse> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`/permissions`, baseUrl);
-    const resp = await libeufinHttpLib.fetch(url.href, {
+    const resp = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return resp.json();
@@ -621,7 +624,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`/permissions`, baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: req,
@@ -634,7 +637,7 @@ export namespace LibeufinNexusApi {
   ): Promise<NexusTaskCollection> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`/bank-accounts/${bankAccountName}/schedule`, baseUrl);
-    const resp = await libeufinHttpLib.fetch(url.href, {
+    const resp = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return resp.json();
@@ -653,7 +656,7 @@ export namespace LibeufinNexusApi {
       baseUrl,
     );
     if (taskName) url = new URL(taskName, `${url.href}/`);
-    const resp = await libeufinHttpLib.fetch(url.href, {
+    const resp = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     return resp.json();
@@ -669,7 +672,7 @@ export namespace LibeufinNexusApi {
       `/bank-accounts/${bankAccountName}/schedule/${taskName}`,
       baseUrl,
     );
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "DELETE",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
@@ -682,7 +685,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`/bank-accounts/${bankAccountName}/schedule`, baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: req,
@@ -695,7 +698,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL(`facades/${facadeName}`, baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "DELETE",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
@@ -706,7 +709,7 @@ export namespace LibeufinNexusApi {
   ): Promise<NexusFacadeListResponse> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL("facades", baseUrl);
-    const resp = await libeufinHttpLib.fetch(url.href, {
+    const resp = await libeufinHarnessHttpLib.fetch(url.href, {
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
     });
     // FIXME: Just return validated, typed response here!
@@ -719,7 +722,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL("facades", baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {
@@ -741,7 +744,7 @@ export namespace LibeufinNexusApi {
   ): Promise<void> {
     const baseUrl = libeufinNexusService.baseUrl;
     let url = new URL("facades", baseUrl);
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {
@@ -766,7 +769,7 @@ export namespace LibeufinNexusApi {
       `/bank-accounts/${accountId}/submit-all-payment-initiations`,
       baseUrl,
     );
-    await libeufinHttpLib.fetch(url.href, {
+    await libeufinHarnessHttpLib.fetch(url.href, {
       method: "POST",
       headers: { Authorization: makeBasicAuthHeader("admin", "secret") },
       body: {},
diff --git a/packages/taler-harness/src/integrationtests/test-age-restrictions-merchant.ts b/packages/taler-harness/src/integrationtests/test-age-restrictions-merchant.ts
index 5ee35a377..3072badc0 100644
--- a/packages/taler-harness/src/integrationtests/test-age-restrictions-merchant.ts
+++ b/packages/taler-harness/src/integrationtests/test-age-restrictions-merchant.ts
@@ -82,13 +82,14 @@ export async function runAgeRestrictionsMerchantTest(t: GlobalTestState) {
         name: "w0",
       });
 
-    await withdrawViaBankV2(t, {
+    const wres = await withdrawViaBankV2(t, {
       walletClient: walletClientZero,
       bank,
       exchange,
       amount: "TESTKUDOS:20",
       restrictAge: 13,
     });
+    await wres.withdrawalFinishedCond;
 
     const order = {
       summary: "Buy me!",
@@ -111,13 +112,14 @@ export async function runAgeRestrictionsMerchantTest(t: GlobalTestState) {
   {
     const walletClient = walletClientOne;
 
-    await withdrawViaBankV2(t, {
+    const wres = await withdrawViaBankV2(t, {
       walletClient,
       bank,
       exchange,
       amount: "TESTKUDOS:20",
       restrictAge: 13,
     });
+    await wres.withdrawalFinishedCond;
 
     const order = {
       summary: "Buy me!",
@@ -136,13 +138,14 @@ export async function runAgeRestrictionsMerchantTest(t: GlobalTestState) {
   {
     const walletClient = walletClientTwo;
 
-    await withdrawViaBankV2(t, {
+    const wres = await withdrawViaBankV2(t, {
       walletClient,
       bank,
       exchange,
       amount: "TESTKUDOS:20",
       restrictAge: 13,
     });
+    await wres.withdrawalFinishedCond;
 
     const order = {
       summary: "Buy me!",
@@ -160,12 +163,13 @@ export async function runAgeRestrictionsMerchantTest(t: GlobalTestState) {
   {
     const walletClient = walletClientThree;
 
-    await withdrawViaBankV2(t, {
+    const wres = await withdrawViaBankV2(t, {
       walletClient,
       bank,
       exchange,
       amount: "TESTKUDOS:20",
     });
+    await wres.withdrawalFinishedCond;
 
     const order = {
       summary: "Buy me!",
diff --git a/packages/taler-harness/src/integrationtests/test-bank-api.ts b/packages/taler-harness/src/integrationtests/test-bank-api.ts
index 041b10cc0..e645d60f1 100644
--- a/packages/taler-harness/src/integrationtests/test-bank-api.ts
+++ b/packages/taler-harness/src/integrationtests/test-bank-api.ts
@@ -84,12 +84,6 @@ export async function runBankApiTest(t: GlobalTestState) {
 
   await merchant.start();
   await merchant.pingUntilAvailable();
-  await merchant.addDefaultInstance();
-  await merchant.addInstanceWithWireAccount({
-    id: "minst1",
-    name: "minst1",
-    paytoUris: [getPayto("minst1")],
-  });
 
   await merchant.addInstanceWithWireAccount({
     id: "default",
@@ -97,6 +91,12 @@ export async function runBankApiTest(t: GlobalTestState) {
     paytoUris: [getPayto("merchant-default")],
   });
 
+  await merchant.addInstanceWithWireAccount({
+    id: "minst1",
+    name: "minst1",
+    paytoUris: [getPayto("minst1")],
+  });
+
   console.log("setup done!");
 
   const bankUser = await BankApi.registerAccount(bank, "user1", "pw1", {});
diff --git a/packages/taler-harness/src/integrationtests/test-libeufin-basic.ts b/packages/taler-harness/src/integrationtests/test-libeufin-basic.ts
index 5d5beb06e..20fa34437 100644
--- a/packages/taler-harness/src/integrationtests/test-libeufin-basic.ts
+++ b/packages/taler-harness/src/integrationtests/test-libeufin-basic.ts
@@ -19,12 +19,12 @@
  */
 import {
   AbsoluteTime,
-  MerchantContractTerms,
   Duration,
+  MerchantContractTerms,
 } from "@gnu-taler/taler-util";
 import {
-  WalletApiOperation,
   HarnessExchangeBankAccount,
+  WalletApiOperation,
 } from "@gnu-taler/taler-wallet-core";
 import { CoinConfig, defaultCoinConfig } from "../harness/denomStructures.js";
 import {
@@ -32,20 +32,19 @@ import {
   ExchangeService,
   GlobalTestState,
   MerchantService,
-  setupDb,
-  WalletCli,
   WalletClient,
+  setupDb,
 } from "../harness/harness.js";
+import {
+  createWalletDaemonWithClient,
+  makeTestPaymentV2,
+} from "../harness/helpers.js";
 import {
   LibeufinNexusApi,
   LibeufinNexusService,
   LibeufinSandboxApi,
   LibeufinSandboxService,
 } from "../harness/libeufin.js";
-import {
-  createWalletDaemonWithClient,
-  makeTestPaymentV2,
-} from "../harness/helpers.js";
 
 const exchangeIban = "DE71500105179674997361";
 const customerIban = "DE84500105176881385584";
@@ -73,7 +72,7 @@ export async function createLibeufinTestEnvironment(
 
   const libeufinSandbox = await LibeufinSandboxService.create(t, {
     httpPort: 5010,
-    databaseJdbcUri: `jdbc:sqlite:${t.testDir}/libeufin-sandbox.sqlite3`,
+    databaseJdbcUri: db.connStr,
   });
 
   await libeufinSandbox.start();
@@ -81,7 +80,7 @@ export async function createLibeufinTestEnvironment(
 
   const libeufinNexus = await LibeufinNexusService.create(t, {
     httpPort: 5011,
-    databaseJdbcUri: `jdbc:sqlite:${t.testDir}/libeufin-nexus.sqlite3`,
+    databaseJdbcUri: db.connStr,
   });
 
   await libeufinNexus.start();
@@ -218,7 +217,7 @@ export async function createLibeufinTestEnvironment(
   console.log("setup done!");
 
   const { walletClient } = await createWalletDaemonWithClient(t, {
-    name: "default ",
+    name: "default",
   });
 
   return {
diff --git a/packages/taler-harness/src/integrationtests/test-merchant-instances.ts b/packages/taler-harness/src/integrationtests/test-merchant-instances.ts
index 167c54cb4..54205e9f2 100644
--- a/packages/taler-harness/src/integrationtests/test-merchant-instances.ts
+++ b/packages/taler-harness/src/integrationtests/test-merchant-instances.ts
@@ -86,6 +86,16 @@ export async function runMerchantInstancesTest(t: GlobalTestState) {
     },
   });
 
+  // Add it again, should be idempotent
+  await merchant.addInstanceWithWireAccount({
+    id: "default",
+    name: "Default Instance",
+    paytoUris: [getPayto("merchant-default")],
+    auth: {
+      method: "external",
+    },
+  });
+
   // Add an instance, no auth!
   await merchant.addInstanceWithWireAccount({
     id: "myinst",