chore(wallet): bump gonuts-tollgate v0.14.0; honest keyset ids in test fakes

changelog.d/1063-gonuts-v0.14.0.changed.md

@@ -0,0 +1 @@
+- The wallet fork pin moves to gonuts-tollgate v0.14.0, picking up the forged-keyset-id refusal (a mint whose advertised keyset id does not match the id its published keys derive to is now rejected — tollgate #705), the refuse-swap-consumed-by-fees guard, pre-persisted swap intents with crash replay, and cached keyset fees. Test fakes now advertise keyset ids their keys actually derive to, as the new guard demands. ([#1063](https://github.com/OpenTollGate/tollgate-module-basic-go/pull/1063))

changelog.d/1077-wallet-init-keyset-self-heal.fixed.md

@@ -0,0 +1 @@
+- Fixed: wallet init no longer bricks into degraded mode when the mint has rotated its keysets since the last sync — with a reachable mint the keyset set is re-fetched (NUT-02) and boot proceeds; retired-keyset records, their derivation counters and any unspent proofs are preserved in the wallet instead of requiring the move-wallet.db-aside recovery ([#1077](https://github.com/OpenTollGate/tollgate-module-basic-go/pull/1077))

changelog.d/908-swap-fee-belt-refusal.fixed.md

@@ -0,0 +1 @@
+- **A token whose value exactly equals its swap fee is refused cleanly, not bounced by the mint.** The wallet used to pass the below-fees guard when the token amount EQUALLED the fee, split zero, and POST a swap with an empty outputs array — the mint's raw NUT-03 400 ("Outputs are required and must be an array", the CU107 portal error) reached the payer instead of a fee verdict. gonuts-tollgate v0.13.1 refuses it locally (and any swap that reaches zero outputs), and the backend maps the refusal to the clear payment-error-below-swap-fee notice ([#908](https://github.com/OpenTollGate/tollgate-module-basic-go/pull/908))

packaging/build-inputs.json

@@ -3,15 +3,15 @@
   "comment": "Immutable build inputs for reproducible tollgate-wrt artifacts. Every byte-affecting external input is pinned here. Update intentionally (see docs/reproducible-builds.md); never point portal.commit at a floating ref.",
   "go": {
     "version": "1.26.10",
-    "comment": "The toolchain that compiles the shipped binaries. SOURCE OF TRUTH: the official golang of the pinned OpenWrt SDK release's packages feed (see .openwrt_sdk.go_per_release) — the feed defines it, so our binaries are reproducible against the SDK's own toolchain; never a minor of our own choosing (#448). scripts/sdk-go-version.sh check enforces it against the live feeds; update re-derives it.",
+    "comment": "The toolchain that compiles the shipped binaries. SOURCE OF TRUTH: the official golang of the pinned OpenWrt SDK release's packages feed (see .openwrt_sdk.go_per_release) \u2014 the feed defines it, so our binaries are reproducible against the SDK's own toolchain; never a minor of our own choosing (#448). scripts/sdk-go-version.sh check enforces it against the live feeds; update re-derives it.",
     "tarball_linux_amd64": {
       "url": "https://go.dev/dl/go1.26.10.linux-amd64.tar.gz",
       "sha256": "ccfe7ae822d2c2f41f4fe7c956199967a4dac22d0ee0d2b2bfdb440aab3b20c5"
     }
   },
   "gonuts": {
     "repo": "https://github.com/OpenTollGate/gonuts-tollgate",
-    "version": "v0.13.0",
+    "version": "v0.14.1",
     "comment": "The wallet fork every Go module pins IDENTICALLY. tests/contract/check-gonuts-pin.py enumerates carriers by glob (never a hand list) and fails on any disagreement with this value; scripts/bump-gonuts.sh rewrites manifest and every carrier together. Before a release is cut, release-check verifies this is the fork's latest stable tag. Pseudo-version integration pins are for branches only and must not outlive their tag on main."
   },
   "node": {
@@ -71,7 +71,7 @@
       },
       "ipk": {
         "release": "24.10.8",
-        "comment": "The ipk/opkg era for the installed base (feed-less 24.10 systems — fork #93/#110 evidence). Digests are the point-release tags from hub.docker.com/openwrt/sdk. The SDK packages STAGED PREBUILT binaries (the manifest-pinned Go compiles on the host), so the era's older feed Go (1.23.x) never compiles our code — go_per_release keeps it audited for awareness.",
+        "comment": "The ipk/opkg era for the installed base (feed-less 24.10 systems \u2014 fork #93/#110 evidence). Digests are the point-release tags from hub.docker.com/openwrt/sdk. The SDK packages STAGED PREBUILT binaries (the manifest-pinned Go compiles on the host), so the era's older feed Go (1.23.x) never compiles our code \u2014 go_per_release keeps it audited for awareness.",
         "targets": {
           "mediatek-filogic": {
             "digest": "sha256:4109260d68a593972d0d0408e6e439472cd02df9a29a3a9383fd52bd97707a4a"

scripts/token-recovery/go.mod

@@ -2,7 +2,7 @@ module token-recovery
 
 go 1.26.0
 
-require github.com/OpenTollGate/gonuts-tollgate v0.13.0
+require github.com/OpenTollGate/gonuts-tollgate v0.14.1
 
 require (
 	github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da // indirect

scripts/token-recovery/go.sum

@@ -6,8 +6,8 @@ github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERo
 github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5 h1:TngWCqHvy9oXAN6lEVMRuU21PR1EtLVZJmdB18Gu3Rw=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5/go.mod h1:lmUJ/7eu/Q8D7ML55dXQrVaamCz2vxCfdQBasLZfHKk=
-github.com/OpenTollGate/gonuts-tollgate v0.13.0 h1:BtxPOSzbSED8ZytVzhEVBXrYgHRlSHqcgoWdhG5evds=
-github.com/OpenTollGate/gonuts-tollgate v0.13.0/go.mod h1:4er8keqQ4yg3Zuz0w1BuXclKSeKOk3SGqsEl4b0oI7M=
+github.com/OpenTollGate/gonuts-tollgate v0.14.1 h1:hLJkL81dMQcz+ZUQkHgbP2MvzxvIVESxTAVSvXiFY08=
+github.com/OpenTollGate/gonuts-tollgate v0.14.1/go.mod h1:4er8keqQ4yg3Zuz0w1BuXclKSeKOk3SGqsEl4b0oI7M=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmHS9iAKVt9AyzRSqNU1qabPih5BY=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=
 github.com/aead/siphash v1.0.1 h1:FwHfE/T45KPKYuuSAKyyvE+oPWcaQ+CUmFW0bPlM+kg=

src/cli/go.mod

@@ -13,7 +13,7 @@ require (
 
 require (
 	github.com/ImVexed/fasturl v0.0.0-20230304231329-4e41488060f3 // indirect
-	github.com/OpenTollGate/gonuts-tollgate v0.13.0 // indirect
+	github.com/OpenTollGate/gonuts-tollgate v0.14.1 // indirect
 	github.com/OpenTollGate/tollgate-module-basic-go/src/lightning v0.0.0-00010101000000-000000000000 // indirect
 	github.com/OpenTollGate/tollgate-module-basic-go/src/tollwallet v0.0.0 // indirect
 	github.com/OpenTollGate/tollgate-module-basic-go/src/utils v0.0.0 // indirect

src/cli/go.sum

@@ -8,8 +8,8 @@ github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERo
 github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5 h1:TngWCqHvy9oXAN6lEVMRuU21PR1EtLVZJmdB18Gu3Rw=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5/go.mod h1:lmUJ/7eu/Q8D7ML55dXQrVaamCz2vxCfdQBasLZfHKk=
-github.com/OpenTollGate/gonuts-tollgate v0.13.0 h1:BtxPOSzbSED8ZytVzhEVBXrYgHRlSHqcgoWdhG5evds=
-github.com/OpenTollGate/gonuts-tollgate v0.13.0/go.mod h1:4er8keqQ4yg3Zuz0w1BuXclKSeKOk3SGqsEl4b0oI7M=
+github.com/OpenTollGate/gonuts-tollgate v0.14.1 h1:hLJkL81dMQcz+ZUQkHgbP2MvzxvIVESxTAVSvXiFY08=
+github.com/OpenTollGate/gonuts-tollgate v0.14.1/go.mod h1:4er8keqQ4yg3Zuz0w1BuXclKSeKOk3SGqsEl4b0oI7M=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmHS9iAKVt9AyzRSqNU1qabPih5BY=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=
 github.com/aead/siphash v1.0.1 h1:FwHfE/T45KPKYuuSAKyyvE+oPWcaQ+CUmFW0bPlM+kg=

src/go.mod

@@ -41,7 +41,7 @@ require (
 	github.com/FactomProject/basen v0.0.0-20150613233007-fe3947df716e // indirect
 	github.com/FactomProject/btcutilecc v0.0.0-20130527213604-d3a63a5752ec // indirect
 	github.com/ImVexed/fasturl v0.0.0-20230304231329-4e41488060f3 // indirect
-	github.com/OpenTollGate/gonuts-tollgate v0.13.0 // indirect
+	github.com/OpenTollGate/gonuts-tollgate v0.14.1 // indirect
 	github.com/OpenTollGate/tollgate-module-basic-go/src/lightning v0.0.0-00010101000000-000000000000 // indirect
 	github.com/OpenTollGate/tollgate-module-basic-go/src/tollgate_protocol v0.0.0 // indirect
 	github.com/OpenTollGate/tollgate-module-basic-go/src/tollwallet v0.0.0 // indirect

src/go.sum

@@ -12,8 +12,8 @@ github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERo
 github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5 h1:TngWCqHvy9oXAN6lEVMRuU21PR1EtLVZJmdB18Gu3Rw=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5/go.mod h1:lmUJ/7eu/Q8D7ML55dXQrVaamCz2vxCfdQBasLZfHKk=
-github.com/OpenTollGate/gonuts-tollgate v0.13.0 h1:BtxPOSzbSED8ZytVzhEVBXrYgHRlSHqcgoWdhG5evds=
-github.com/OpenTollGate/gonuts-tollgate v0.13.0/go.mod h1:4er8keqQ4yg3Zuz0w1BuXclKSeKOk3SGqsEl4b0oI7M=
+github.com/OpenTollGate/gonuts-tollgate v0.14.1 h1:hLJkL81dMQcz+ZUQkHgbP2MvzxvIVESxTAVSvXiFY08=
+github.com/OpenTollGate/gonuts-tollgate v0.14.1/go.mod h1:4er8keqQ4yg3Zuz0w1BuXclKSeKOk3SGqsEl4b0oI7M=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmHS9iAKVt9AyzRSqNU1qabPih5BY=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=
 github.com/aead/siphash v1.0.1 h1:FwHfE/T45KPKYuuSAKyyvE+oPWcaQ+CUmFW0bPlM+kg=

src/merchant/go.mod

@@ -3,11 +3,12 @@ module github.com/OpenTollGate/tollgate-module-basic-go/src/merchant
 go 1.26.0
 
 require (
-	github.com/OpenTollGate/gonuts-tollgate v0.13.0
+	github.com/OpenTollGate/gonuts-tollgate v0.14.1
 	github.com/OpenTollGate/tollgate-module-basic-go/src/config_manager v0.0.0
 	github.com/OpenTollGate/tollgate-module-basic-go/src/tollwallet v0.0.0
 	github.com/OpenTollGate/tollgate-module-basic-go/src/utils v0.0.0
 	github.com/OpenTollGate/tollgate-module-basic-go/src/valve v0.0.0
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0
 	github.com/nbd-wtf/go-nostr v0.51.12
 	golang.org/x/time v0.15.0
 )
@@ -78,7 +79,6 @@ require (
 	github.com/cloudwego/base64x v0.1.5 // indirect
 	github.com/coder/websocket v1.8.13 // indirect
 	github.com/decred/dcrd/crypto/blake256 v1.1.0 // indirect
-	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0 // indirect
 	github.com/fxamacker/cbor/v2 v2.8.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect

src/merchant/go.sum

@@ -8,8 +8,8 @@ github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERo
 github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5 h1:TngWCqHvy9oXAN6lEVMRuU21PR1EtLVZJmdB18Gu3Rw=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5/go.mod h1:lmUJ/7eu/Q8D7ML55dXQrVaamCz2vxCfdQBasLZfHKk=
-github.com/OpenTollGate/gonuts-tollgate v0.13.0 h1:BtxPOSzbSED8ZytVzhEVBXrYgHRlSHqcgoWdhG5evds=
-github.com/OpenTollGate/gonuts-tollgate v0.13.0/go.mod h1:4er8keqQ4yg3Zuz0w1BuXclKSeKOk3SGqsEl4b0oI7M=
+github.com/OpenTollGate/gonuts-tollgate v0.14.1 h1:hLJkL81dMQcz+ZUQkHgbP2MvzxvIVESxTAVSvXiFY08=
+github.com/OpenTollGate/gonuts-tollgate v0.14.1/go.mod h1:4er8keqQ4yg3Zuz0w1BuXclKSeKOk3SGqsEl4b0oI7M=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmHS9iAKVt9AyzRSqNU1qabPih5BY=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=
 github.com/aead/siphash v1.0.1 h1:FwHfE/T45KPKYuuSAKyyvE+oPWcaQ+CUmFW0bPlM+kg=

src/merchant/merchant.go

@@ -1866,6 +1866,10 @@ func isBelowSwapFeeError(err error) bool {
 	msg := strings.ToLower(err.Error())
 	return strings.Contains(msg, "nothing to swap") ||
 		strings.Contains(msg, "no outputs provided") ||
+		// gonuts-tollgate v0.13.1's belt check (#752): a swap that reached
+		// zero outputs through any path is refused before the mint is
+		// asked — same fee-vs-value family, same clean notice.
+		strings.Contains(msg, "produced no outputs") ||
 		strings.Contains(msg, "swap fees")
 }
 

src/merchant/merchant_degraded_recovery_test.go

@@ -28,10 +28,13 @@ func newSwitchableMintServer(t *testing.T) *switchableMintServer {
 		switch r.URL.Path {
 		case "/v1/keysets":
 			w.Header().Set("Content-Type", "application/json")
-			fmt.Fprint(w, `{"keysets":[{"id":"00ad268c4d1f5826","unit":"sat","active":true,"input_fee_ppk":0}]}`)
+			// 000f715baf5d4c2e is what DeriveKeysetId derives for this fake's
+			// amount-1 key (the generator point) — v0.14.0's #705 guard
+			// refuses ids the published keys do not derive to.
+			fmt.Fprint(w, `{"keysets":[{"id":"000f715baf5d4c2e","unit":"sat","active":true,"input_fee_ppk":0}]}`)
 		case "/v1/keys":
 			w.Header().Set("Content-Type", "application/json")
-			fmt.Fprint(w, `{"keysets":[{"id":"00ad268c4d1f5826","unit":"sat","active":true,"keys":{"1":"0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798"}}]}`)
+			fmt.Fprint(w, `{"keysets":[{"id":"000f715baf5d4c2e","unit":"sat","active":true,"keys":{"1":"0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798"}}]}`)
 		default:
 			w.Header().Set("Content-Type", "application/json")
 			fmt.Fprint(w, `{}`)

src/merchant/merchant_degraded_test.go

@@ -26,7 +26,7 @@ func TestNewFullMerchant_WalletInitFail_FallsBackToDegraded(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.URL.Path == "/v1/keysets" {
 			w.Header().Set("Content-Type", "application/json")
-			fmt.Fprint(w, `{"keysets":[{"id":"00ad268c4d1f5826","unit":"sat","active":true}]}`)
+			fmt.Fprint(w, `{"keysets":[{"id":"000f715baf5d4c2e","unit":"sat","active":true}]}`)
 			return
 		}
 		http.Error(w, "internal server error", http.StatusInternalServerError)

src/merchant/merchant_health_test.go

@@ -17,7 +17,7 @@ func reachableServer(t *testing.T) *httptest.Server {
 		w.Header().Set("Content-Type", "application/json")
 		w.WriteHeader(http.StatusOK)
 		if r.URL.Path == "/v1/keysets" {
-			_, _ = w.Write([]byte(`{"keysets":[{"id":"00ad268c4d1f5826","unit":"sat","active":true}]}`))
+			_, _ = w.Write([]byte(`{"keysets":[{"id":"000f715baf5d4c2e","unit":"sat","active":true}]}`))
 		}
 	}))
 	t.Cleanup(srv.Close)
@@ -225,7 +225,7 @@ func TestProbeMint_TrailingSlashTrimmed(t *testing.T) {
 		requestedPath = r.URL.Path
 		w.Header().Set("Content-Type", "application/json")
 		writeKeysetsOK(w)
-		_, _ = w.Write([]byte(`{"keysets":[{"id":"00ad268c4d1f5826","unit":"sat","active":true}]}`))
+		_, _ = w.Write([]byte(`{"keysets":[{"id":"000f715baf5d4c2e","unit":"sat","active":true}]}`))
 	}))
 	defer srv.Close()
 

src/merchant/merchant_keyset_rotation_init_test.go

@@ -0,0 +1,123 @@
+package merchant
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"sync/atomic"
+	"testing"
+
+	"github.com/OpenTollGate/gonuts-tollgate/crypto"
+	"github.com/OpenTollGate/gonuts-tollgate/wallet"
+	"github.com/OpenTollGate/tollgate-module-basic-go/src/config_manager"
+	"github.com/decred/dcrd/dcrec/secp256k1/v4"
+)
+
+// The #818 slice at the merchant level: booting against a REACHABLE mint
+// that has rotated its keyset set since the wallet last synced must reach
+// "=== Merchant ready ===", not the degraded mode the issue shipped
+// ("Wallet initialization failed (… Unknown Keyset) — starting in degraded
+// mode" with a first-reachable trigger that never fires because the mint
+// was reachable all along).
+//
+// The fake mint is reachable on every keyset endpoint but no longer knows
+// the stale keyset id the pre-rotation wallet.db still has as its active
+// record — the exact desk-run shape from the issue.
+
+// honestStaleKeysetID derives a second honest id (a keyset this mint never
+// served, standing in for one it has retired and dropped).
+func honestStaleKeysetID(t *testing.T) string {
+	t.Helper()
+	priv, err := secp256k1.GeneratePrivateKey()
+	if err != nil {
+		t.Fatalf("generate private key: %v", err)
+	}
+	return crypto.DeriveKeysetId(crypto.PublicKeys{1: priv.PubKey()})
+}
+
+func seedRetiredKeysetWallet(t *testing.T, dir, mintURL, staleID string) {
+	t.Helper()
+	if err := os.MkdirAll(dir, 0o700); err != nil {
+		t.Fatalf("mkdir wallet dir: %v", err)
+	}
+	db, err := wallet.InitStorage(dir)
+	if err != nil {
+		t.Fatalf("seed InitStorage: %v", err)
+	}
+	rec := crypto.WalletKeyset{Id: staleID, MintURL: mintURL, Unit: "sat", Active: true}
+	if err := db.SaveKeyset(&rec); err != nil {
+		t.Fatalf("seed SaveKeyset: %v", err)
+	}
+	if err := db.Close(); err != nil {
+		t.Fatalf("seed close: %v", err)
+	}
+}
+
+// TestMerchantReadyUnderKeysetRotation_Issue818 boots the full startup
+// path (probe → wallet → advertisement) with a rotated mint and a
+// pre-rotation wallet: the merchant must come up READY.
+func TestMerchantReadyUnderKeysetRotation_Issue818(t *testing.T) {
+	staleID := honestStaleKeysetID(t)
+	var keysetsProbes atomic.Int32
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/v1/keysets":
+			keysetsProbes.Add(1)
+			w.Header().Set("Content-Type", "application/json")
+			// 000f715baf5d4c2e is what DeriveKeysetId derives for this fake's
+			// amount-1 key (the generator point) — v0.14.0's #705 guard
+			// refuses ids the published keys do not derive to.
+			fmt.Fprint(w, `{"keysets":[{"id":"000f715baf5d4c2e","unit":"sat","active":true,"input_fee_ppk":0}]}`)
+		case "/v1/keys":
+			w.Header().Set("Content-Type", "application/json")
+			fmt.Fprint(w, `{"keysets":[{"id":"000f715baf5d4c2e","unit":"sat","active":true,"keys":{"1":"0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798"}}]}`)
+		case "/v1/keys/" + staleID:
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusBadRequest)
+			fmt.Fprint(w, `{"detail":"Unknown Keyset","code":12001}`)
+		default:
+			w.Header().Set("Content-Type", "application/json")
+			fmt.Fprint(w, `{}`)
+		}
+	}))
+	t.Cleanup(srv.Close)
+
+	cm, testDir := setupTestConfigManager(t)
+	// GetConfig returns a defensive copy — the mutation must be persisted
+	// and reloaded, or the merchant boots against the factory-default mint
+	// (the first version of this test "passed" by reaching coinos.io).
+	cfg := cm.GetConfig()
+	cfg.AcceptedMints = simpleMintConfig(srv.URL)
+	if err := config_manager.SaveConfig(cm.ConfigFilePath, cfg); err != nil {
+		t.Fatalf("SaveConfig: %v", err)
+	}
+	if err := cm.ReloadConfig(); err != nil {
+		t.Fatalf("ReloadConfig: %v", err)
+	}
+
+	// The pre-rotation wallet lives where the merchant will look for it:
+	// next to the config file (filepath.Dir of ConfigFilePath).
+	seedRetiredKeysetWallet(t, testDir, srv.URL, staleID)
+
+	m, err := New(cm)
+	if err != nil {
+		t.Fatalf("New: %v", err)
+	}
+	if s, ok := m.(interface{ Shutdown() error }); ok {
+		defer func() { _ = s.Shutdown() }()
+	}
+	if _, degraded := m.(*MerchantDegraded); degraded {
+		t.Fatal("merchant degraded at boot under keyset rotation with a reachable mint — the #818 brick")
+	}
+	full, ok := m.(*Merchant)
+	if !ok {
+		t.Fatalf("New returned %T, want *Merchant", m)
+	}
+	if got := full.GetBalance(); got != 0 {
+		t.Fatalf("balance: want 0 got %d", got)
+	}
+	if keysetsProbes.Load() == 0 {
+		t.Fatal("the merchant never probed the rotating mint — the test did not exercise it")
+	}
+}

src/merchant/merchant_swap_fee_test.go

@@ -53,6 +53,13 @@ func TestIsBelowSwapFeeError(t *testing.T) {
 		want bool
 	}{
 		{"could not swap proofs: token amount 1 is below the mint's swap fees (1): nothing to swap", true},
+		// gonuts-tollgate v0.13.1 (#752): the amount == fee case used to
+		// pass the wallet's below-fees guard and POST an empty outputs
+		// array — the mint's raw CU107 400 reached the payer. The wallet
+		// now refuses it with this message, and the classifier must map
+		// it to the same clean below-swap-fee notice.
+		{"could not swap proofs: token amount 1 is entirely consumed by the mint's swap fees (1): nothing to swap", true},
+		{"could not swap proofs: swap request for 1 sat (fees 1) produced no outputs: refusing to send an empty swap", true},
 		{"could not swap proofs: no outputs provided", true},
 		{"token already spent", false},
 		{"short keyset ID 0118 not found in mint keysets", false},

src/merchant/mint_health_tracker_test.go

@@ -46,7 +46,7 @@ func newTestTracker(config *config_manager.Config, client *http.Client) *MintHea
 func writeKeysetsOK(w http.ResponseWriter) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(http.StatusOK)
-	_, _ = w.Write([]byte(`{"keysets":[{"id":"00ad268c4d1f5826","unit":"sat","active":true}]}`))
+	_, _ = w.Write([]byte(`{"keysets":[{"id":"000f715baf5d4c2e","unit":"sat","active":true}]}`))
 }
 
 // --- Unit Tests ---