Merge pull request #1429 from neavo/fix/gemini-python-sdk-thinking-fields

fix(gemini): support snake_case thinking config fields from Python SDK

internal/thinking/apply.go

@@ -388,7 +388,12 @@ func extractGeminiConfig(body []byte, provider string) ThinkingConfig {
 	}
 
 	// Check thinkingLevel first (Gemini 3 format takes precedence)
-	if level := gjson.GetBytes(body, prefix+".thinkingLevel"); level.Exists() {
+	level := gjson.GetBytes(body, prefix+".thinkingLevel")
+	if !level.Exists() {
+		// Google official Gemini Python SDK sends snake_case field names
+		level = gjson.GetBytes(body, prefix+".thinking_level")
+	}
+	if level.Exists() {
 		value := level.String()
 		switch value {
 		case "none":
@@ -401,7 +406,12 @@ func extractGeminiConfig(body []byte, provider string) ThinkingConfig {
 	}
 
 	// Check thinkingBudget (Gemini 2.5 format)
-	if budget := gjson.GetBytes(body, prefix+".thinkingBudget"); budget.Exists() {
+	budget := gjson.GetBytes(body, prefix+".thinkingBudget")
+	if !budget.Exists() {
+		// Google official Gemini Python SDK sends snake_case field names
+		budget = gjson.GetBytes(body, prefix+".thinking_budget")
+	}
+	if budget.Exists() {
 		value := int(budget.Int())
 		switch value {
 		case 0:

internal/thinking/provider/antigravity/apply.go

@@ -94,8 +94,10 @@ func (a *Applier) applyCompatible(body []byte, config thinking.ThinkingConfig, m
 }
 
 func (a *Applier) applyLevelFormat(body []byte, config thinking.ThinkingConfig) ([]byte, error) {
-	// Remove conflicting field to avoid both thinkingLevel and thinkingBudget in output
+	// Remove conflicting fields to avoid both thinkingLevel and thinkingBudget in output
 	result, _ := sjson.DeleteBytes(body, "request.generationConfig.thinkingConfig.thinkingBudget")
+	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.thinking_budget")
+	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.thinking_level")
 	// Normalize includeThoughts field name to avoid oneof conflicts in upstream JSON parsing.
 	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.include_thoughts")
 
@@ -114,28 +116,30 @@ func (a *Applier) applyLevelFormat(body []byte, config thinking.ThinkingConfig)
 
 	level := string(config.Level)
 	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.thinkingLevel", level)
-	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.includeThoughts", true)
+
+	// Respect user's explicit includeThoughts setting from original body; default to true if not set
+	// Support both camelCase and snake_case variants
+	includeThoughts := true
+	if inc := gjson.GetBytes(body, "request.generationConfig.thinkingConfig.includeThoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+	} else if inc := gjson.GetBytes(body, "request.generationConfig.thinkingConfig.include_thoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+	}
+	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.includeThoughts", includeThoughts)
 	return result, nil
 }
 
 func (a *Applier) applyBudgetFormat(body []byte, config thinking.ThinkingConfig, modelInfo *registry.ModelInfo, isClaude bool) ([]byte, error) {
-	// Remove conflicting field to avoid both thinkingLevel and thinkingBudget in output
+	// Remove conflicting fields to avoid both thinkingLevel and thinkingBudget in output
 	result, _ := sjson.DeleteBytes(body, "request.generationConfig.thinkingConfig.thinkingLevel")
+	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.thinking_level")
+	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.thinking_budget")
 	// Normalize includeThoughts field name to avoid oneof conflicts in upstream JSON parsing.
 	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.include_thoughts")
 
 	budget := config.Budget
-	includeThoughts := false
-	switch config.Mode {
-	case thinking.ModeNone:
-		includeThoughts = false
-	case thinking.ModeAuto:
-		includeThoughts = true
-	default:
-		includeThoughts = budget > 0
-	}
 
-	// Apply Claude-specific constraints
+	// Apply Claude-specific constraints first to get the final budget value
 	if isClaude && modelInfo != nil {
 		budget, result = a.normalizeClaudeBudget(budget, result, modelInfo)
 		// Check if budget was removed entirely
@@ -144,6 +148,37 @@ func (a *Applier) applyBudgetFormat(body []byte, config thinking.ThinkingConfig,
 		}
 	}
 
+	// For ModeNone, always set includeThoughts to false regardless of user setting.
+	// This ensures that when user requests budget=0 (disable thinking output),
+	// the includeThoughts is correctly set to false even if budget is clamped to min.
+	if config.Mode == thinking.ModeNone {
+		result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.thinkingBudget", budget)
+		result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.includeThoughts", false)
+		return result, nil
+	}
+
+	// Determine includeThoughts: respect user's explicit setting from original body if provided
+	// Support both camelCase and snake_case variants
+	var includeThoughts bool
+	var userSetIncludeThoughts bool
+	if inc := gjson.GetBytes(body, "request.generationConfig.thinkingConfig.includeThoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+		userSetIncludeThoughts = true
+	} else if inc := gjson.GetBytes(body, "request.generationConfig.thinkingConfig.include_thoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+		userSetIncludeThoughts = true
+	}
+
+	if !userSetIncludeThoughts {
+		// No explicit setting, use default logic based on mode
+		switch config.Mode {
+		case thinking.ModeAuto:
+			includeThoughts = true
+		default:
+			includeThoughts = budget > 0
+		}
+	}
+
 	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.thinkingBudget", budget)
 	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.includeThoughts", includeThoughts)
 	return result, nil

internal/thinking/provider/gemini/apply.go

@@ -118,8 +118,10 @@ func (a *Applier) applyLevelFormat(body []byte, config thinking.ThinkingConfig)
 	//   - ModeNone + Budget>0: forced to think but hide output (includeThoughts=false)
 	// ValidateConfig sets config.Level to the lowest level when ModeNone + Budget > 0.
 
-	// Remove conflicting field to avoid both thinkingLevel and thinkingBudget in output
+	// Remove conflicting fields to avoid both thinkingLevel and thinkingBudget in output
 	result, _ := sjson.DeleteBytes(body, "generationConfig.thinkingConfig.thinkingBudget")
+	result, _ = sjson.DeleteBytes(result, "generationConfig.thinkingConfig.thinking_budget")
+	result, _ = sjson.DeleteBytes(result, "generationConfig.thinkingConfig.thinking_level")
 	// Normalize includeThoughts field name to avoid oneof conflicts in upstream JSON parsing.
 	result, _ = sjson.DeleteBytes(result, "generationConfig.thinkingConfig.include_thoughts")
 
@@ -138,30 +140,59 @@ func (a *Applier) applyLevelFormat(body []byte, config thinking.ThinkingConfig)
 
 	level := string(config.Level)
 	result, _ = sjson.SetBytes(result, "generationConfig.thinkingConfig.thinkingLevel", level)
-	result, _ = sjson.SetBytes(result, "generationConfig.thinkingConfig.includeThoughts", true)
+
+	// Respect user's explicit includeThoughts setting from original body; default to true if not set
+	// Support both camelCase and snake_case variants
+	includeThoughts := true
+	if inc := gjson.GetBytes(body, "generationConfig.thinkingConfig.includeThoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+	} else if inc := gjson.GetBytes(body, "generationConfig.thinkingConfig.include_thoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+	}
+	result, _ = sjson.SetBytes(result, "generationConfig.thinkingConfig.includeThoughts", includeThoughts)
 	return result, nil
 }
 
 func (a *Applier) applyBudgetFormat(body []byte, config thinking.ThinkingConfig) ([]byte, error) {
-	// Remove conflicting field to avoid both thinkingLevel and thinkingBudget in output
+	// Remove conflicting fields to avoid both thinkingLevel and thinkingBudget in output
 	result, _ := sjson.DeleteBytes(body, "generationConfig.thinkingConfig.thinkingLevel")
+	result, _ = sjson.DeleteBytes(result, "generationConfig.thinkingConfig.thinking_level")
+	result, _ = sjson.DeleteBytes(result, "generationConfig.thinkingConfig.thinking_budget")
 	// Normalize includeThoughts field name to avoid oneof conflicts in upstream JSON parsing.
 	result, _ = sjson.DeleteBytes(result, "generationConfig.thinkingConfig.include_thoughts")
 
 	budget := config.Budget
-	// ModeNone semantics:
+
-	//   - ModeNone + Budget=0: completely disable thinking
+	// For ModeNone, always set includeThoughts to false regardless of user setting.
-	//   - ModeNone + Budget>0: forced to think but hide output (includeThoughts=false)
+	// This ensures that when user requests budget=0 (disable thinking output),
-	// When ZeroAllowed=false, ValidateConfig clamps Budget to Min while preserving ModeNone.
+	// the includeThoughts is correctly set to false even if budget is clamped to min.
-	includeThoughts := false
+	if config.Mode == thinking.ModeNone {
+		result, _ = sjson.SetBytes(result, "generationConfig.thinkingConfig.thinkingBudget", budget)
+		result, _ = sjson.SetBytes(result, "generationConfig.thinkingConfig.includeThoughts", false)
+		return result, nil
+	}
+
+	// Determine includeThoughts: respect user's explicit setting from original body if provided
+	// Support both camelCase and snake_case variants
+	var includeThoughts bool
+	var userSetIncludeThoughts bool
+	if inc := gjson.GetBytes(body, "generationConfig.thinkingConfig.includeThoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+		userSetIncludeThoughts = true
+	} else if inc := gjson.GetBytes(body, "generationConfig.thinkingConfig.include_thoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+		userSetIncludeThoughts = true
+	}
+
+	if !userSetIncludeThoughts {
+		// No explicit setting, use default logic based on mode
 		switch config.Mode {
-	case thinking.ModeNone:
-		includeThoughts = false
 		case thinking.ModeAuto:
 			includeThoughts = true
 		default:
 			includeThoughts = budget > 0
 		}
+	}
 
 	result, _ = sjson.SetBytes(result, "generationConfig.thinkingConfig.thinkingBudget", budget)
 	result, _ = sjson.SetBytes(result, "generationConfig.thinkingConfig.includeThoughts", includeThoughts)

internal/thinking/provider/geminicli/apply.go

@@ -79,8 +79,10 @@ func (a *Applier) applyCompatible(body []byte, config thinking.ThinkingConfig) (
 }
 
 func (a *Applier) applyLevelFormat(body []byte, config thinking.ThinkingConfig) ([]byte, error) {
-	// Remove conflicting field to avoid both thinkingLevel and thinkingBudget in output
+	// Remove conflicting fields to avoid both thinkingLevel and thinkingBudget in output
 	result, _ := sjson.DeleteBytes(body, "request.generationConfig.thinkingConfig.thinkingBudget")
+	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.thinking_budget")
+	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.thinking_level")
 	// Normalize includeThoughts field name to avoid oneof conflicts in upstream JSON parsing.
 	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.include_thoughts")
 
@@ -99,26 +101,59 @@ func (a *Applier) applyLevelFormat(body []byte, config thinking.ThinkingConfig)
 
 	level := string(config.Level)
 	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.thinkingLevel", level)
-	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.includeThoughts", true)
+
+	// Respect user's explicit includeThoughts setting from original body; default to true if not set
+	// Support both camelCase and snake_case variants
+	includeThoughts := true
+	if inc := gjson.GetBytes(body, "request.generationConfig.thinkingConfig.includeThoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+	} else if inc := gjson.GetBytes(body, "request.generationConfig.thinkingConfig.include_thoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+	}
+	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.includeThoughts", includeThoughts)
 	return result, nil
 }
 
 func (a *Applier) applyBudgetFormat(body []byte, config thinking.ThinkingConfig) ([]byte, error) {
-	// Remove conflicting field to avoid both thinkingLevel and thinkingBudget in output
+	// Remove conflicting fields to avoid both thinkingLevel and thinkingBudget in output
 	result, _ := sjson.DeleteBytes(body, "request.generationConfig.thinkingConfig.thinkingLevel")
+	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.thinking_level")
+	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.thinking_budget")
 	// Normalize includeThoughts field name to avoid oneof conflicts in upstream JSON parsing.
 	result, _ = sjson.DeleteBytes(result, "request.generationConfig.thinkingConfig.include_thoughts")
 
 	budget := config.Budget
-	includeThoughts := false
+
+	// For ModeNone, always set includeThoughts to false regardless of user setting.
+	// This ensures that when user requests budget=0 (disable thinking output),
+	// the includeThoughts is correctly set to false even if budget is clamped to min.
+	if config.Mode == thinking.ModeNone {
+		result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.thinkingBudget", budget)
+		result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.includeThoughts", false)
+		return result, nil
+	}
+
+	// Determine includeThoughts: respect user's explicit setting from original body if provided
+	// Support both camelCase and snake_case variants
+	var includeThoughts bool
+	var userSetIncludeThoughts bool
+	if inc := gjson.GetBytes(body, "request.generationConfig.thinkingConfig.includeThoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+		userSetIncludeThoughts = true
+	} else if inc := gjson.GetBytes(body, "request.generationConfig.thinkingConfig.include_thoughts"); inc.Exists() {
+		includeThoughts = inc.Bool()
+		userSetIncludeThoughts = true
+	}
+
+	if !userSetIncludeThoughts {
+		// No explicit setting, use default logic based on mode
 		switch config.Mode {
-	case thinking.ModeNone:
-		includeThoughts = false
 		case thinking.ModeAuto:
 			includeThoughts = true
 		default:
 			includeThoughts = budget > 0
 		}
+	}
 
 	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.thinkingBudget", budget)
 	result, _ = sjson.SetBytes(result, "request.generationConfig.thinkingConfig.includeThoughts", includeThoughts)

internal/translator/claude/gemini/claude_gemini_request.go

@@ -116,7 +116,11 @@ func ConvertGeminiRequestToClaude(modelName string, inputRawJSON []byte, stream
 		// Include thoughts configuration for reasoning process visibility
 		// Translator only does format conversion, ApplyThinking handles model capability validation.
 		if thinkingConfig := genConfig.Get("thinkingConfig"); thinkingConfig.Exists() && thinkingConfig.IsObject() {
-			if thinkingLevel := thinkingConfig.Get("thinkingLevel"); thinkingLevel.Exists() {
+			thinkingLevel := thinkingConfig.Get("thinkingLevel")
+			if !thinkingLevel.Exists() {
+				thinkingLevel = thinkingConfig.Get("thinking_level")
+			}
+			if thinkingLevel.Exists() {
 				level := strings.ToLower(strings.TrimSpace(thinkingLevel.String()))
 				switch level {
 				case "":
@@ -132,7 +136,12 @@ func ConvertGeminiRequestToClaude(modelName string, inputRawJSON []byte, stream
 						out, _ = sjson.Set(out, "thinking.budget_tokens", budget)
 					}
 				}
-			} else if thinkingBudget := thinkingConfig.Get("thinkingBudget"); thinkingBudget.Exists() {
+			} else {
+				thinkingBudget := thinkingConfig.Get("thinkingBudget")
+				if !thinkingBudget.Exists() {
+					thinkingBudget = thinkingConfig.Get("thinking_budget")
+				}
+				if thinkingBudget.Exists() {
 					budget := int(thinkingBudget.Int())
 					switch budget {
 					case 0:
@@ -152,6 +161,7 @@ func ConvertGeminiRequestToClaude(modelName string, inputRawJSON []byte, stream
 				}
 			}
 		}
+	}
 
 	// System instruction conversion to Claude Code format
 	if sysInstr := root.Get("system_instruction"); sysInstr.Exists() {

internal/translator/codex/gemini/codex_gemini_request.go

@@ -243,16 +243,26 @@ func ConvertGeminiRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 	out, _ = sjson.Set(out, "parallel_tool_calls", true)
 
 	// Convert Gemini thinkingConfig to Codex reasoning.effort.
+	// Note: Google official Python SDK sends snake_case fields (thinking_level/thinking_budget).
 	effortSet := false
 	if genConfig := root.Get("generationConfig"); genConfig.Exists() {
 		if thinkingConfig := genConfig.Get("thinkingConfig"); thinkingConfig.Exists() && thinkingConfig.IsObject() {
-			if thinkingLevel := thinkingConfig.Get("thinkingLevel"); thinkingLevel.Exists() {
+			thinkingLevel := thinkingConfig.Get("thinkingLevel")
+			if !thinkingLevel.Exists() {
+				thinkingLevel = thinkingConfig.Get("thinking_level")
+			}
+			if thinkingLevel.Exists() {
 				effort := strings.ToLower(strings.TrimSpace(thinkingLevel.String()))
 				if effort != "" {
 					out, _ = sjson.Set(out, "reasoning.effort", effort)
 					effortSet = true
 				}
-			} else if thinkingBudget := thinkingConfig.Get("thinkingBudget"); thinkingBudget.Exists() {
+			} else {
+				thinkingBudget := thinkingConfig.Get("thinkingBudget")
+				if !thinkingBudget.Exists() {
+					thinkingBudget = thinkingConfig.Get("thinking_budget")
+				}
+				if thinkingBudget.Exists() {
 					if effort, ok := thinking.ConvertBudgetToLevel(int(thinkingBudget.Int())); ok {
 						out, _ = sjson.Set(out, "reasoning.effort", effort)
 						effortSet = true
@@ -260,6 +270,7 @@ func ConvertGeminiRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 				}
 			}
 		}
+	}
 	if !effortSet {
 		// No thinking config, set default effort
 		out, _ = sjson.Set(out, "reasoning.effort", "medium")

internal/translator/openai/gemini/openai_gemini_request.go

@@ -83,20 +83,31 @@ func ConvertGeminiRequestToOpenAI(modelName string, inputRawJSON []byte, stream
 		}
 
 		// Map Gemini thinkingConfig to OpenAI reasoning_effort.
-		// Always perform conversion to support allowCompat models that may not be in registry
+		// Always perform conversion to support allowCompat models that may not be in registry.
+		// Note: Google official Python SDK sends snake_case fields (thinking_level/thinking_budget).
 		if thinkingConfig := genConfig.Get("thinkingConfig"); thinkingConfig.Exists() && thinkingConfig.IsObject() {
-			if thinkingLevel := thinkingConfig.Get("thinkingLevel"); thinkingLevel.Exists() {
+			thinkingLevel := thinkingConfig.Get("thinkingLevel")
+			if !thinkingLevel.Exists() {
+				thinkingLevel = thinkingConfig.Get("thinking_level")
+			}
+			if thinkingLevel.Exists() {
 				effort := strings.ToLower(strings.TrimSpace(thinkingLevel.String()))
 				if effort != "" {
 					out, _ = sjson.Set(out, "reasoning_effort", effort)
 				}
-			} else if thinkingBudget := thinkingConfig.Get("thinkingBudget"); thinkingBudget.Exists() {
+			} else {
+				thinkingBudget := thinkingConfig.Get("thinkingBudget")
+				if !thinkingBudget.Exists() {
+					thinkingBudget = thinkingConfig.Get("thinking_budget")
+				}
+				if thinkingBudget.Exists() {
 					if effort, ok := thinking.ConvertBudgetToLevel(int(thinkingBudget.Int())); ok {
 						out, _ = sjson.Set(out, "reasoning_effort", effort)
 					}
 				}
 			}
 		}
+	}
 
 	// Stream parameter
 	out, _ = sjson.Set(out, "stream", stream)