Detect free models that became paid

Author: dzarlax

internal/adminapi/adminapi_test.go

@@ -383,6 +383,26 @@ func TestTGAdminModelCheckRejectsPaidModel(t *testing.T) {
 	}
 }
 
+func TestFailedModelCheckBlocksFreeModelsThatBecamePaid(t *testing.T) {
+	cases := []string{
+		"api error (HTTP 404): This model is unavailable for free. The paid version is available now - use this slug instead: minimax/minimax-m2.5",
+		"api error (HTTP 404): Hy3 preview is no longer available as a free model. It has transitioned to a paid model.",
+	}
+	for _, message := range cases {
+		status := failedModelCheck(message, 23)
+		if status.Status != "free_blocked" {
+			t.Fatalf("status = %s, want free_blocked for %q", status.Status, message)
+		}
+	}
+}
+
+func TestFailedModelCheckKeepsTransientFailuresDegraded(t *testing.T) {
+	status := failedModelCheck("api error (HTTP 500): upstream temporarily unavailable", 91)
+	if status.Status != "free_degraded" {
+		t.Fatalf("status = %s, want free_degraded", status.Status)
+	}
+}
+
 func TestFreeModelCheckCandidatesSkipFreshChecks(t *testing.T) {
 	s, _ := newTGModelTestServer(t)
 	fresh := time.Now().Add(-time.Hour).Format(time.RFC3339)

internal/adminapi/model_checks.go

@@ -188,8 +188,7 @@ func (s *Server) probeModel(ctx context.Context, providerType, modelID string, c
 
 func failedModelCheck(message string, latencyMS int64) modelCheckStatus {
 	status := "free_degraded"
-	lower := strings.ToLower(message)
-	if strings.Contains(lower, "429") || strings.Contains(lower, "rate") || strings.Contains(lower, "quota") {
+	if isBlockedModelCheckError(message) {
 		status = "free_blocked"
 	}
 	return modelCheckStatus{
@@ -200,6 +199,25 @@ func failedModelCheck(message string, latencyMS int64) modelCheckStatus {
 	}
 }
 
+func isBlockedModelCheckError(message string) bool {
+	lower := strings.ToLower(message)
+	for _, needle := range []string{
+		"429",
+		"rate",
+		"quota",
+		"no longer available as a free model",
+		"unavailable for free",
+		"paid version is available",
+		"transitioned to a paid model",
+		"has become paid",
+	} {
+		if strings.Contains(lower, needle) {
+			return true
+		}
+	}
+	return false
+}
+
 func (s *Server) startModelCheckScheduler() {
 	if s.settings == nil || s.capStore == nil || s.cfgRef == nil {
 		return