diff --git a/main.go b/main.go
index c4cfa6a..0a4d3b8 100644
--- a/main.go
+++ b/main.go
@@ -414,7 +414,7 @@ func ResolveMaxTokens(req ChatCompletionRequest) int {
     mt = req.MaxCompletionTokens
   }
   if mt <= 0 {
-    mt = 8192
+    mt = 4096
   }
   if mt > 32768 {
     mt = 32768
@@ -1633,11 +1633,29 @@ func (s *QwenService) chatGradioRespond(endpointURL string, w http.ResponseWrite
   if req.Temperature != nil {
     tempVal = *req.Temperature
   }
+  if tempVal < 0.0 {
+    tempVal = 0.0
+  } else if tempVal > 2.0 {
+    tempVal = 2.0
+  }
 
   topPVal := 0.95
   if req.TopP != nil {
     topPVal = *req.TopP
   }
+  if topPVal < 0.0 {
+    topPVal = 0.0
+  } else if topPVal > 1.0 {
+    topPVal = 1.0
+  }
+
+  // MicroHERO /respond endpoint has a slider with strict range [64, 4096]
+  clampedTokens := maxTokens
+  if clampedTokens > 4096 {
+    clampedTokens = 4096
+  } else if clampedTokens < 64 {
+    clampedTokens = 64
+  }
 
   effUA := EffectiveUserAgent(r)
   effHFToken := EffectiveHFToken(r)
@@ -1650,7 +1668,7 @@ func (s *QwenService) chatGradioRespond(endpointURL string, w http.ResponseWrite
       "text":  promptText,
       "files": []interface{}{},
     },
-    maxTokens,
+    clampedTokens,
     tempVal,
     topPVal,
   }
@@ -1887,6 +1905,11 @@ func (s *QwenService) chatGradioChatResponse(endpointURL string, w http.Response
   } else if !enableThinking {
     tempVal = 0.7
   }
+  if tempVal < 0.0 {
+    tempVal = 0.0
+  } else if tempVal > 2.0 {
+    tempVal = 2.0
+  }
 
   topPVal := 0.95
   if req.TopP != nil {
@@ -1894,12 +1917,30 @@ func (s *QwenService) chatGradioChatResponse(endpointURL string, w http.Response
   } else if !enableThinking {
     topPVal = 0.80
   }
+  if topPVal < 0.1 {
+    topPVal = 0.1
+  } else if topPVal > 1.0 {
+    topPVal = 1.0
+  }
 
   topKVal := 20
   presenceVal := 0.0
   if !enableThinking {
     presenceVal = 1.5
   }
+  if presenceVal < 0.0 {
+    presenceVal = 0.0
+  } else if presenceVal > 2.0 {
+    presenceVal = 2.0
+  }
+
+  // Halvo78 /chat_response slider range is [256, 32768]
+  clampedTokens := maxTokens
+  if clampedTokens > 32768 {
+    clampedTokens = 32768
+  } else if clampedTokens < 256 {
+    clampedTokens = 256
+  }
 
   customAPIKey := EffectiveUpstreamKey(r)
   if customAPIKey == "" {
@@ -1943,7 +1984,7 @@ func (s *QwenService) chatGradioChatResponse(endpointURL string, w http.Response
     topPVal,
     topKVal,
     presenceVal,
-    maxTokens,
+    clampedTokens,
     systemPromptStr,
     customBaseURL,
     customAPIKey,
diff --git a/qflash_test.go b/qflash_test.go
index ec5c340..ccc019c 100644
--- a/qflash_test.go
+++ b/qflash_test.go
@@ -626,4 +626,27 @@ func TestQwenServiceAutoFailover(t *testing.T) {
   }
 }
 
+func TestResolveMaxTokens(t *testing.T) {
+  // Default when empty
+  if v := ResolveMaxTokens(ChatCompletionRequest{}); v != 4096 {
+    t.Fatalf("expected default 4096, got %d", v)
+  }
+
+  // Explicit max_tokens
+  if v := ResolveMaxTokens(ChatCompletionRequest{MaxTokens: 2048}); v != 2048 {
+    t.Fatalf("expected 2048, got %d", v)
+  }
+
+  // max_completion_tokens precedence when max_tokens is 0
+  if v := ResolveMaxTokens(ChatCompletionRequest{MaxCompletionTokens: 1024}); v != 1024 {
+    t.Fatalf("expected 1024, got %d", v)
+  }
+
+  // Cap at 32768
+  if v := ResolveMaxTokens(ChatCompletionRequest{MaxTokens: 65536}); v != 32768 {
+    t.Fatalf("expected cap at 32768, got %d", v)
+  }
+}
+
+