diff --git a/internal/acp/orchestrator.go b/internal/acp/orchestrator.go
index da33adb..4de7330 100644
--- a/internal/acp/orchestrator.go
+++ b/internal/acp/orchestrator.go
@@ -613,13 +613,19 @@ func (o *SessionOrchestrator) openClawArtifactPrepare(
 
 func isOpenClawUnknownMethodError(errorPayload map[string]any, method string) bool {
 	message := strings.ToLower(strings.TrimSpace(shared.StringArg(errorPayload, "message", "")))
-	code := strings.ToUpper(strings.TrimSpace(shared.StringArg(errorPayload, "code", "")))
 	if message == "" {
 		return false
 	}
+	// 消息形如「unknown method: <method>」已明确指向「网关不认识该方法」，足以判定，
+	// 据此走 graceful fallback（如 openClawFallbackSessionPreparePayload）。
+	//
+	// 注意：不能再用严格的 code 白名单来 gate。真实网关常以数字 JSON-RPC code
+	// (-32601 method not found / -32600 invalid request / -32002 等) 回传，
+	// 经 shared.StringArg(fmt.Sprint) 会被字符串化为 "-32601"/"-32002"，
+	// 旧实现只接受 {"", INVALID_REQUEST, METHOD_NOT_FOUND}，导致 fallback 失效、
+	// session.prepare 直接以 -32002 硬失败整轮任务。
 	return strings.Contains(message, "unknown method") &&
-		strings.Contains(message, strings.ToLower(strings.TrimSpace(method))) &&
-		(code == "" || code == "INVALID_REQUEST" || code == "METHOD_NOT_FOUND")
+		strings.Contains(message, strings.ToLower(strings.TrimSpace(method)))
 }
 
 func openClawFallbackSessionPreparePayload(params map[string]any) map[string]any {
diff --git a/internal/acp/orchestrator_normalize_result_test.go b/internal/acp/orchestrator_normalize_result_test.go
index e4e9372..4536dd5 100644
--- a/internal/acp/orchestrator_normalize_result_test.go
+++ b/internal/acp/orchestrator_normalize_result_test.go
@@ -282,3 +282,50 @@ func TestTaskGetArtifactExportReceivesRequiredArtifactExtensions(t *testing.T) {
 		t.Fatalf("expected expectedFileCountByExtension to reach export, got %#v", exportParams)
 	}
 }
+
+func TestIsOpenClawUnknownMethodErrorAcceptsNumericGatewayCodes(t *testing.T) {
+	const method = "xworkmate.session.prepare"
+	cases := []struct {
+		name    string
+		payload map[string]any
+		want    bool
+	}{
+		{
+			name:    "string invalid_request code",
+			payload: map[string]any{"code": "INVALID_REQUEST", "message": "unknown method: xworkmate.session.prepare"},
+			want:    true,
+		},
+		{
+			name:    "numeric -32002 (real gateway shape that previously hard-failed)",
+			payload: map[string]any{"code": float64(-32002), "message": "unknown method: xworkmate.session.prepare"},
+			want:    true,
+		},
+		{
+			name:    "numeric -32601 method not found",
+			payload: map[string]any{"code": float64(-32601), "message": "Unknown method: xworkmate.session.prepare"},
+			want:    true,
+		},
+		{
+			name:    "empty code",
+			payload: map[string]any{"message": "unknown method: xworkmate.session.prepare"},
+			want:    true,
+		},
+		{
+			name:    "unrelated error must not be swallowed",
+			payload: map[string]any{"code": float64(-32002), "message": "gateway socket closed"},
+			want:    false,
+		},
+		{
+			name:    "unknown method for a different method name",
+			payload: map[string]any{"code": float64(-32601), "message": "unknown method: chat.send"},
+			want:    false,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := isOpenClawUnknownMethodError(tc.payload, method); got != tc.want {
+				t.Fatalf("isOpenClawUnknownMethodError(%v) = %v, want %v", tc.payload, got, tc.want)
+			}
+		})
+	}
+}