From 5c40a2db215b17a1f0f7d383bfb29c18f647eb2b Mon Sep 17 00:00:00 2001
From: hkfires <10558748+hkfires@users.noreply.github.com>
Date: Thu, 15 Jan 2026 14:03:08 +0800
Subject: [PATCH] refactor(thinking): simplify ModeNone and budget validation
 logic

---
 internal/registry/model_definitions.go |  4 ++--
 internal/thinking/validate.go          | 33 +++++++++++---------------
 2 files changed, 16 insertions(+), 21 deletions(-)

diff --git a/internal/registry/model_definitions.go b/internal/registry/model_definitions.go
index b8ca8757..13fc8177 100644
--- a/internal/registry/model_definitions.go
+++ b/internal/registry/model_definitions.go
@@ -777,8 +777,8 @@ func GetAntigravityModelConfig() map[string]*AntigravityModelConfig {
 		"gemini-3-pro-high":          {Thinking: &ThinkingSupport{Min: 128, Max: 32768, ZeroAllowed: false, DynamicAllowed: true, Levels: []string{"low", "high"}}, Name: "models/gemini-3-pro-high"},
 		"gemini-3-pro-image":         {Thinking: &ThinkingSupport{Min: 128, Max: 32768, ZeroAllowed: false, DynamicAllowed: true, Levels: []string{"low", "high"}}, Name: "models/gemini-3-pro-image"},
 		"gemini-3-flash":             {Thinking: &ThinkingSupport{Min: 128, Max: 32768, ZeroAllowed: false, DynamicAllowed: true, Levels: []string{"minimal", "low", "medium", "high"}}, Name: "models/gemini-3-flash"},
-		"claude-sonnet-4-5-thinking": {Thinking: &ThinkingSupport{Min: 1024, Max: 128000, ZeroAllowed: true, DynamicAllowed: false}, MaxCompletionTokens: 64000},
-		"claude-opus-4-5-thinking":   {Thinking: &ThinkingSupport{Min: 1024, Max: 128000, ZeroAllowed: true, DynamicAllowed: false}, MaxCompletionTokens: 64000},
+		"claude-sonnet-4-5-thinking": {Thinking: &ThinkingSupport{Min: 1024, Max: 128000, ZeroAllowed: true, DynamicAllowed: true}, MaxCompletionTokens: 64000},
+		"claude-opus-4-5-thinking":   {Thinking: &ThinkingSupport{Min: 1024, Max: 128000, ZeroAllowed: true, DynamicAllowed: true}, MaxCompletionTokens: 64000},
 	}
 }
 
diff --git a/internal/thinking/validate.go b/internal/thinking/validate.go
index 799c8005..897a64a3 100644
--- a/internal/thinking/validate.go
+++ b/internal/thinking/validate.go
@@ -159,27 +159,22 @@ func ValidateConfig(config ThinkingConfig, modelInfo *registry.ModelInfo, provid
 		normalized = convertAutoToMidRange(normalized, support, provider, model)
 	}
 
-	// ModeNone handling varies by provider/model capability:
-	// - Claude can always disable thinking via thinking.type="disabled".
-	// - Some models/providers cannot be fully disabled; for those we force minimal thinking
-	//   while hiding thoughts (ModeNone + Budget>0 and/or Level set).
-	if normalized.Mode == ModeNone {
-		if provider == "claude" {
-			normalized.Budget = 0
-			normalized.Level = ""
-		} else if !support.ZeroAllowed {
-			if support.Min > 0 {
-				normalized.Budget = support.Min
-			}
-			if normalized.Level == "" && normalized.Budget > 0 && len(support.Levels) > 0 {
-				normalized.Level = ThinkingLevel(support.Levels[0])
-			}
+	if normalized.Mode == ModeNone && provider == "claude" {
+		// Claude supports explicit disable via thinking.type="disabled".
+		// Keep Budget=0 so applier can omit budget_tokens.
+		normalized.Budget = 0
+		normalized.Level = ""
+	} else {
+		switch normalized.Mode {
+		case ModeBudget, ModeAuto, ModeNone:
+			normalized.Budget = ClampBudget(normalized.Budget, modelInfo, provider)
 		}
-	}
 
-	switch normalized.Mode {
-	case ModeBudget, ModeAuto:
-		normalized.Budget = ClampBudget(normalized.Budget, modelInfo, provider)
+		// ModeNone with clamped Budget > 0: set Level to lowest for Level-only/Hybrid models
+		// This ensures Apply layer doesn't need to access support.Levels
+		if normalized.Mode == ModeNone && normalized.Budget > 0 && len(support.Levels) > 0 {
+			normalized.Level = ThinkingLevel(support.Levels[0])
+		}
 	}
 
 	return &normalized, nil