feat(util): implement dynamic thinking suffix normalization and refactor budget resolution logic

- Added support for parsing and normalizing dynamic thinking model suffixes.
- Centralized budget resolution across executors and payload helpers.
- Retired legacy Gemini-specific thinking handlers in favor of unified logic.
- Updated executors to use metadata-based thinking configuration.
- Added `ResolveOriginalModel` utility for resolving normalized upstream models using request metadata.
- Updated executors (Gemini, Codex, iFlow, OpenAI, Qwen) to incorporate upstream model resolution and substitute model values in payloads and request URLs.
- Ensured fallbacks handle cases with missing or malformed metadata to derive models robustly.
- Refactored upstream model resolution to dynamically incorporate metadata for selecting and normalizing models.
- Improved handling of thinking configurations and model overrides in executors.
- Removed hardcoded thinking model entries and migrated logic to metadata-based resolution.
- Updated payload mutations to always include the resolved model.

internal/api/modules/amp/fallback_handlers.go

@@ -133,8 +133,8 @@ func (fh *FallbackHandler) WrapHandler(handler gin.HandlerFunc) gin.HandlerFunc
 			return
 		}
 
-		// Normalize model (handles Gemini thinking suffixes)
+		// Normalize model (handles dynamic thinking suffixes)
-		normalizedModel, _ := util.NormalizeGeminiThinkingModel(modelName)
+		normalizedModel, _ := util.NormalizeThinkingModel(modelName)
 
 		// Track resolved model for logging (may change if mapping is applied)
 		resolvedModel := normalizedModel

internal/registry/model_definitions.go

@@ -26,60 +26,6 @@ func GetClaudeModels() []*ModelInfo {
 			DisplayName:         "Claude 4.5 Sonnet",
 			ContextLength:       200000,
 			MaxCompletionTokens: 64000,
-		},
-		{
-			ID:                  "claude-sonnet-4-5-thinking",
-			Object:              "model",
-			Created:             1759104000, // 2025-09-29
-			OwnedBy:             "anthropic",
-			Type:                "claude",
-			DisplayName:         "Claude 4.5 Sonnet Thinking",
-			ContextLength:       200000,
-			MaxCompletionTokens: 64000,
-			Thinking:            &ThinkingSupport{Min: 1024, Max: 100000, ZeroAllowed: false, DynamicAllowed: true},
-		},
-		{
-			ID:                  "claude-opus-4-5-thinking",
-			Object:              "model",
-			Created:             1761955200, // 2025-11-01
-			OwnedBy:             "anthropic",
-			Type:                "claude",
-			DisplayName:         "Claude 4.5 Opus Thinking",
-			ContextLength:       200000,
-			MaxCompletionTokens: 64000,
-			Thinking:            &ThinkingSupport{Min: 1024, Max: 100000, ZeroAllowed: false, DynamicAllowed: true},
-		},
-		{
-			ID:                  "claude-opus-4-5-thinking-low",
-			Object:              "model",
-			Created:             1761955200, // 2025-11-01
-			OwnedBy:             "anthropic",
-			Type:                "claude",
-			DisplayName:         "Claude 4.5 Opus Thinking Low",
-			ContextLength:       200000,
-			MaxCompletionTokens: 64000,
-			Thinking:            &ThinkingSupport{Min: 1024, Max: 100000, ZeroAllowed: false, DynamicAllowed: true},
-		},
-		{
-			ID:                  "claude-opus-4-5-thinking-medium",
-			Object:              "model",
-			Created:             1761955200, // 2025-11-01
-			OwnedBy:             "anthropic",
-			Type:                "claude",
-			DisplayName:         "Claude 4.5 Opus Thinking Medium",
-			ContextLength:       200000,
-			MaxCompletionTokens: 64000,
-			Thinking:            &ThinkingSupport{Min: 1024, Max: 100000, ZeroAllowed: false, DynamicAllowed: true},
-		},
-		{
-			ID:                  "claude-opus-4-5-thinking-high",
-			Object:              "model",
-			Created:             1761955200, // 2025-11-01
-			OwnedBy:             "anthropic",
-			Type:                "claude",
-			DisplayName:         "Claude 4.5 Opus Thinking High",
-			ContextLength:       200000,
-			MaxCompletionTokens: 64000,
 			Thinking:            &ThinkingSupport{Min: 1024, Max: 100000, ZeroAllowed: false, DynamicAllowed: true},
 		},
 		{
@@ -92,6 +38,7 @@ func GetClaudeModels() []*ModelInfo {
 			Description:         "Premium model combining maximum intelligence with practical performance",
 			ContextLength:       200000,
 			MaxCompletionTokens: 64000,
+			Thinking:            &ThinkingSupport{Min: 1024, Max: 100000, ZeroAllowed: false, DynamicAllowed: true},
 		},
 		{
 			ID:                  "claude-opus-4-1-20250805",
@@ -530,58 +477,6 @@ func GetOpenAIModels() []*ModelInfo {
 			MaxCompletionTokens: 128000,
 			SupportedParameters: []string{"tools"},
 		},
-		{
-			ID:                  "gpt-5-minimal",
-			Object:              "model",
-			Created:             1754524800,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-08-07",
-			DisplayName:         "GPT 5 Minimal",
-			Description:         "Stable version of GPT 5, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5-low",
-			Object:              "model",
-			Created:             1754524800,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-08-07",
-			DisplayName:         "GPT 5 Low",
-			Description:         "Stable version of GPT 5, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5-medium",
-			Object:              "model",
-			Created:             1754524800,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-08-07",
-			DisplayName:         "GPT 5 Medium",
-			Description:         "Stable version of GPT 5, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5-high",
-			Object:              "model",
-			Created:             1754524800,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-08-07",
-			DisplayName:         "GPT 5 High",
-			Description:         "Stable version of GPT 5, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
 		{
 			ID:                  "gpt-5-codex",
 			Object:              "model",
@@ -595,45 +490,6 @@ func GetOpenAIModels() []*ModelInfo {
 			MaxCompletionTokens: 128000,
 			SupportedParameters: []string{"tools"},
 		},
-		{
-			ID:                  "gpt-5-codex-low",
-			Object:              "model",
-			Created:             1757894400,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-09-15",
-			DisplayName:         "GPT 5 Codex Low",
-			Description:         "Stable version of GPT 5 Codex, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5-codex-medium",
-			Object:              "model",
-			Created:             1757894400,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-09-15",
-			DisplayName:         "GPT 5 Codex Medium",
-			Description:         "Stable version of GPT 5 Codex, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5-codex-high",
-			Object:              "model",
-			Created:             1757894400,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-09-15",
-			DisplayName:         "GPT 5 Codex High",
-			Description:         "Stable version of GPT 5 Codex, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
 		{
 			ID:                  "gpt-5-codex-mini",
 			Object:              "model",
@@ -647,32 +503,6 @@ func GetOpenAIModels() []*ModelInfo {
 			MaxCompletionTokens: 128000,
 			SupportedParameters: []string{"tools"},
 		},
-		{
-			ID:                  "gpt-5-codex-mini-medium",
-			Object:              "model",
-			Created:             1762473600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-11-07",
-			DisplayName:         "GPT 5 Codex Mini Medium",
-			Description:         "Stable version of GPT 5 Codex Mini: cheaper, faster, but less capable version of GPT 5 Codex.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5-codex-mini-high",
-			Object:              "model",
-			Created:             1762473600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5-2025-11-07",
-			DisplayName:         "GPT 5 Codex Mini High",
-			Description:         "Stable version of GPT 5 Codex Mini: cheaper, faster, but less capable version of GPT 5 Codex.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
 		{
 			ID:                  "gpt-5.1",
 			Object:              "model",
@@ -686,58 +516,6 @@ func GetOpenAIModels() []*ModelInfo {
 			MaxCompletionTokens: 128000,
 			SupportedParameters: []string{"tools"},
 		},
-		{
-			ID:                  "gpt-5.1-none",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5.1 Nothink",
-			Description:         "Stable version of GPT 5.1, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-low",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5 Low",
-			Description:         "Stable version of GPT 5, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-medium",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5.1 Medium",
-			Description:         "Stable version of GPT 5.1, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-high",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5.1 High",
-			Description:         "Stable version of GPT 5.1, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
 		{
 			ID:                  "gpt-5.1-codex",
 			Object:              "model",
@@ -751,45 +529,6 @@ func GetOpenAIModels() []*ModelInfo {
 			MaxCompletionTokens: 128000,
 			SupportedParameters: []string{"tools"},
 		},
-		{
-			ID:                  "gpt-5.1-codex-low",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5.1 Codex Low",
-			Description:         "Stable version of GPT 5.1 Codex, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-codex-medium",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5.1 Codex Medium",
-			Description:         "Stable version of GPT 5.1 Codex, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-codex-high",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5.1 Codex High",
-			Description:         "Stable version of GPT 5.1 Codex, The best model for coding and agentic tasks across domains.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
 		{
 			ID:                  "gpt-5.1-codex-mini",
 			Object:              "model",
@@ -803,33 +542,6 @@ func GetOpenAIModels() []*ModelInfo {
 			MaxCompletionTokens: 128000,
 			SupportedParameters: []string{"tools"},
 		},
-		{
-			ID:                  "gpt-5.1-codex-mini-medium",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5.1 Codex Mini Medium",
-			Description:         "Stable version of GPT 5.1 Codex Mini: cheaper, faster, but less capable version of GPT 5.1 Codex.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-codex-mini-high",
-			Object:              "model",
-			Created:             1762905600,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-2025-11-12",
-			DisplayName:         "GPT 5.1 Codex Mini High",
-			Description:         "Stable version of GPT 5.1 Codex Mini: cheaper, faster, but less capable version of GPT 5.1 Codex.",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-
 		{
 			ID:                  "gpt-5.1-codex-max",
 			Object:              "model",
@@ -843,58 +555,6 @@ func GetOpenAIModels() []*ModelInfo {
 			MaxCompletionTokens: 128000,
 			SupportedParameters: []string{"tools"},
 		},
-		{
-			ID:                  "gpt-5.1-codex-max-low",
-			Object:              "model",
-			Created:             1763424000,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-max",
-			DisplayName:         "GPT 5.1 Codex Max Low",
-			Description:         "Stable version of GPT 5.1 Codex Max Low",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-codex-max-medium",
-			Object:              "model",
-			Created:             1763424000,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-max",
-			DisplayName:         "GPT 5.1 Codex Max Medium",
-			Description:         "Stable version of GPT 5.1 Codex Max Medium",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-codex-max-high",
-			Object:              "model",
-			Created:             1763424000,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-max",
-			DisplayName:         "GPT 5.1 Codex Max High",
-			Description:         "Stable version of GPT 5.1 Codex Max High",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
-		{
-			ID:                  "gpt-5.1-codex-max-xhigh",
-			Object:              "model",
-			Created:             1763424000,
-			OwnedBy:             "openai",
-			Type:                "openai",
-			Version:             "gpt-5.1-max",
-			DisplayName:         "GPT 5.1 Codex Max XHigh",
-			Description:         "Stable version of GPT 5.1 Codex Max XHigh",
-			ContextLength:       400000,
-			MaxCompletionTokens: 128000,
-			SupportedParameters: []string{"tools"},
-		},
 	}
 }
 

internal/runtime/executor/claude_executor.go

@@ -54,15 +54,22 @@ func (e *ClaudeExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	// Use streaming translation to preserve function calling, except for claude.
 	stream := from != to
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), stream)
-	modelForUpstream := req.Model
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
-	if modelOverride := e.resolveUpstreamModel(req.Model, auth); modelOverride != "" {
+	if upstreamModel == "" {
-		body, _ = sjson.SetBytes(body, "model", modelOverride)
+		upstreamModel = req.Model
-		modelForUpstream = modelOverride
 	}
-	// Inject thinking config based on model suffix for thinking variants
+	if modelOverride := e.resolveUpstreamModel(upstreamModel, auth); modelOverride != "" {
-	body = e.injectThinkingConfig(req.Model, body)
+		upstreamModel = modelOverride
+	} else if !strings.EqualFold(upstreamModel, req.Model) {
+		if modelOverride := e.resolveUpstreamModel(req.Model, auth); modelOverride != "" {
+			upstreamModel = modelOverride
+		}
+	}
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
+	// Inject thinking config based on model metadata for thinking variants
+	body = e.injectThinkingConfig(req.Model, req.Metadata, body)
 
-	if !strings.HasPrefix(modelForUpstream, "claude-3-5-haiku") {
+	if !strings.HasPrefix(upstreamModel, "claude-3-5-haiku") {
 		body = checkSystemInstructions(body)
 	}
 	body = applyPayloadConfig(e.cfg, req.Model, body)
@@ -161,11 +168,20 @@ func (e *ClaudeExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("claude")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
-	if modelOverride := e.resolveUpstreamModel(req.Model, auth); modelOverride != "" {
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
-		body, _ = sjson.SetBytes(body, "model", modelOverride)
+	if upstreamModel == "" {
+		upstreamModel = req.Model
 	}
-	// Inject thinking config based on model suffix for thinking variants
+	if modelOverride := e.resolveUpstreamModel(upstreamModel, auth); modelOverride != "" {
-	body = e.injectThinkingConfig(req.Model, body)
+		upstreamModel = modelOverride
+	} else if !strings.EqualFold(upstreamModel, req.Model) {
+		if modelOverride := e.resolveUpstreamModel(req.Model, auth); modelOverride != "" {
+			upstreamModel = modelOverride
+		}
+	}
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
+	// Inject thinking config based on model metadata for thinking variants
+	body = e.injectThinkingConfig(req.Model, req.Metadata, body)
 	body = checkSystemInstructions(body)
 	body = applyPayloadConfig(e.cfg, req.Model, body)
 
@@ -295,13 +311,20 @@ func (e *ClaudeExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Aut
 	// Use streaming translation to preserve function calling, except for claude.
 	stream := from != to
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), stream)
-	modelForUpstream := req.Model
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
-	if modelOverride := e.resolveUpstreamModel(req.Model, auth); modelOverride != "" {
+	if upstreamModel == "" {
-		body, _ = sjson.SetBytes(body, "model", modelOverride)
+		upstreamModel = req.Model
-		modelForUpstream = modelOverride
 	}
+	if modelOverride := e.resolveUpstreamModel(upstreamModel, auth); modelOverride != "" {
+		upstreamModel = modelOverride
+	} else if !strings.EqualFold(upstreamModel, req.Model) {
+		if modelOverride := e.resolveUpstreamModel(req.Model, auth); modelOverride != "" {
+			upstreamModel = modelOverride
+		}
+	}
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 
-	if !strings.HasPrefix(modelForUpstream, "claude-3-5-haiku") {
+	if !strings.HasPrefix(upstreamModel, "claude-3-5-haiku") {
 		body = checkSystemInstructions(body)
 	}
 
@@ -427,25 +450,15 @@ func extractAndRemoveBetas(body []byte) ([]string, []byte) {
 	return betas, body
 }
 
-// injectThinkingConfig adds thinking configuration based on model name suffix
+// injectThinkingConfig adds thinking configuration based on metadata or legacy suffixes.
-func (e *ClaudeExecutor) injectThinkingConfig(modelName string, body []byte) []byte {
+func (e *ClaudeExecutor) injectThinkingConfig(modelName string, metadata map[string]any, body []byte) []byte {
 	// Only inject if thinking config is not already present
 	if gjson.GetBytes(body, "thinking").Exists() {
 		return body
 	}
 
-	var budgetTokens int
+	budgetTokens, ok := resolveClaudeThinkingBudget(modelName, metadata)
-	switch {
+	if !ok || budgetTokens <= 0 {
-	case strings.HasSuffix(modelName, "-thinking-low"):
-		budgetTokens = 1024
-	case strings.HasSuffix(modelName, "-thinking-medium"):
-		budgetTokens = 8192
-	case strings.HasSuffix(modelName, "-thinking-high"):
-		budgetTokens = 24576
-	case strings.HasSuffix(modelName, "-thinking"):
-		// Default thinking without suffix uses medium budget
-		budgetTokens = 8192
-	default:
 		return body
 	}
 
@@ -454,6 +467,44 @@ func (e *ClaudeExecutor) injectThinkingConfig(modelName string, body []byte) []b
 	return body
 }
 
+func resolveClaudeThinkingBudget(modelName string, metadata map[string]any) (int, bool) {
+	budget, include, effort, matched := util.ThinkingFromMetadata(metadata)
+	if matched {
+		if include != nil && !*include {
+			return 0, false
+		}
+		if budget != nil {
+			normalized := util.NormalizeThinkingBudget(modelName, *budget)
+			if normalized > 0 {
+				return normalized, true
+			}
+			return 0, false
+		}
+		if effort != nil {
+			if derived, ok := util.ThinkingEffortToBudget(modelName, *effort); ok && derived > 0 {
+				return derived, true
+			}
+		}
+	}
+	return claudeBudgetFromSuffix(modelName)
+}
+
+func claudeBudgetFromSuffix(modelName string) (int, bool) {
+	lower := strings.ToLower(strings.TrimSpace(modelName))
+	switch {
+	case strings.HasSuffix(lower, "-thinking-low"):
+		return 1024, true
+	case strings.HasSuffix(lower, "-thinking-medium"):
+		return 8192, true
+	case strings.HasSuffix(lower, "-thinking-high"):
+		return 24576, true
+	case strings.HasSuffix(lower, "-thinking"):
+		return 8192, true
+	default:
+		return 0, false
+	}
+}
+
 // ensureMaxTokensForThinking ensures max_tokens > thinking.budget_tokens when thinking is enabled.
 // Anthropic API requires this constraint; violating it returns a 400 error.
 // This function should be called after all thinking configuration is finalized.
@@ -491,35 +542,45 @@ func ensureMaxTokensForThinking(modelName string, body []byte) []byte {
 }
 
 func (e *ClaudeExecutor) resolveUpstreamModel(alias string, auth *cliproxyauth.Auth) string {
-	if alias == "" {
+	trimmed := strings.TrimSpace(alias)
+	if trimmed == "" {
 		return ""
 	}
-	// Hardcoded mappings for thinking models to actual Claude model names
+
-	switch alias {
-	case "claude-opus-4-5-thinking", "claude-opus-4-5-thinking-low", "claude-opus-4-5-thinking-medium", "claude-opus-4-5-thinking-high":
-		return "claude-opus-4-5-20251101"
-	case "claude-sonnet-4-5-thinking":
-		return "claude-sonnet-4-5-20250929"
-	}
 	entry := e.resolveClaudeConfig(auth)
 	if entry == nil {
 		return ""
 	}
+
+	normalizedModel, metadata := util.NormalizeThinkingModel(trimmed)
+
+	// Candidate names to match against configured aliases/names.
+	candidates := []string{strings.TrimSpace(normalizedModel)}
+	if !strings.EqualFold(normalizedModel, trimmed) {
+		candidates = append(candidates, trimmed)
+	}
+	if original := util.ResolveOriginalModel(normalizedModel, metadata); original != "" && !strings.EqualFold(original, normalizedModel) {
+		candidates = append(candidates, original)
+	}
+
 	for i := range entry.Models {
 		model := entry.Models[i]
 		name := strings.TrimSpace(model.Name)
 		modelAlias := strings.TrimSpace(model.Alias)
-		if modelAlias != "" {
+
-			if strings.EqualFold(modelAlias, alias) {
+		for _, candidate := range candidates {
+			if candidate == "" {
+				continue
+			}
+			if modelAlias != "" && strings.EqualFold(modelAlias, candidate) {
 				if name != "" {
 					return name
 				}
-				return alias
+				return candidate
+			}
+			if name != "" && strings.EqualFold(name, candidate) {
+				return name
 			}
-			continue
-		}
-		if name != "" && strings.EqualFold(name, alias) {
-			return name
 		}
 	}
 	return ""

internal/runtime/executor/codex_executor.go

@@ -49,14 +49,14 @@ func (e *CodexExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, re
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
 
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("codex")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
-
+	body = applyReasoningEffortMetadata(body, req.Metadata, req.Model)
-	body = e.setReasoningEffortByAlias(req.Model, body)
-
 	body = applyPayloadConfig(e.cfg, req.Model, body)
-
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 	body, _ = sjson.SetBytes(body, "stream", true)
 	body, _ = sjson.DeleteBytes(body, "previous_response_id")
 
@@ -142,13 +142,16 @@ func (e *CodexExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Au
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
 
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("codex")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
 
-	body = e.setReasoningEffortByAlias(req.Model, body)
+	body = applyReasoningEffortMetadata(body, req.Metadata, req.Model)
 	body = applyPayloadConfig(e.cfg, req.Model, body)
 	body, _ = sjson.DeleteBytes(body, "previous_response_id")
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 
 	url := strings.TrimSuffix(baseURL, "/") + "/responses"
 	httpReq, err := e.cacheHelper(ctx, from, url, req, body)
@@ -235,14 +238,16 @@ func (e *CodexExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Au
 }
 
 func (e *CodexExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("codex")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
 
 	modelForCounting := req.Model
 
-	body = e.setReasoningEffortByAlias(req.Model, body)
+	body = applyReasoningEffortMetadata(body, req.Metadata, req.Model)
-
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 	body, _ = sjson.DeleteBytes(body, "previous_response_id")
 	body, _ = sjson.SetBytes(body, "stream", false)
 
@@ -261,83 +266,6 @@ func (e *CodexExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Auth
 	return cliproxyexecutor.Response{Payload: []byte(translated)}, nil
 }
 
-func (e *CodexExecutor) setReasoningEffortByAlias(modelName string, payload []byte) []byte {
-	if util.InArray([]string{"gpt-5", "gpt-5-minimal", "gpt-5-low", "gpt-5-medium", "gpt-5-high"}, modelName) {
-		payload, _ = sjson.SetBytes(payload, "model", "gpt-5")
-		switch modelName {
-		case "gpt-5-minimal":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "minimal")
-		case "gpt-5-low":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "low")
-		case "gpt-5-medium":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "medium")
-		case "gpt-5-high":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "high")
-		}
-	} else if util.InArray([]string{"gpt-5-codex", "gpt-5-codex-low", "gpt-5-codex-medium", "gpt-5-codex-high"}, modelName) {
-		payload, _ = sjson.SetBytes(payload, "model", "gpt-5-codex")
-		switch modelName {
-		case "gpt-5-codex-low":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "low")
-		case "gpt-5-codex-medium":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "medium")
-		case "gpt-5-codex-high":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "high")
-		}
-	} else if util.InArray([]string{"gpt-5-codex-mini", "gpt-5-codex-mini-medium", "gpt-5-codex-mini-high"}, modelName) {
-		payload, _ = sjson.SetBytes(payload, "model", "gpt-5-codex-mini")
-		switch modelName {
-		case "gpt-5-codex-mini-medium":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "medium")
-		case "gpt-5-codex-mini-high":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "high")
-		}
-	} else if util.InArray([]string{"gpt-5.1", "gpt-5.1-none", "gpt-5.1-low", "gpt-5.1-medium", "gpt-5.1-high"}, modelName) {
-		payload, _ = sjson.SetBytes(payload, "model", "gpt-5.1")
-		switch modelName {
-		case "gpt-5.1-none":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "none")
-		case "gpt-5.1-low":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "low")
-		case "gpt-5.1-medium":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "medium")
-		case "gpt-5.1-high":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "high")
-		}
-	} else if util.InArray([]string{"gpt-5.1-codex", "gpt-5.1-codex-low", "gpt-5.1-codex-medium", "gpt-5.1-codex-high"}, modelName) {
-		payload, _ = sjson.SetBytes(payload, "model", "gpt-5.1-codex")
-		switch modelName {
-		case "gpt-5.1-codex-low":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "low")
-		case "gpt-5.1-codex-medium":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "medium")
-		case "gpt-5.1-codex-high":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "high")
-		}
-	} else if util.InArray([]string{"gpt-5.1-codex-mini", "gpt-5.1-codex-mini-medium", "gpt-5.1-codex-mini-high"}, modelName) {
-		payload, _ = sjson.SetBytes(payload, "model", "gpt-5.1-codex-mini")
-		switch modelName {
-		case "gpt-5.1-codex-mini-medium":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "medium")
-		case "gpt-5.1-codex-mini-high":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "high")
-		}
-	} else if util.InArray([]string{"gpt-5.1-codex-max", "gpt-5.1-codex-max-low", "gpt-5.1-codex-max-medium", "gpt-5.1-codex-max-high", "gpt-5.1-codex-max-xhigh"}, modelName) {
-		payload, _ = sjson.SetBytes(payload, "model", "gpt-5.1-codex-max")
-		switch modelName {
-		case "gpt-5.1-codex-max-low":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "low")
-		case "gpt-5.1-codex-max-medium":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "medium")
-		case "gpt-5.1-codex-max-high":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "high")
-		case "gpt-5.1-codex-max-xhigh":
-			payload, _ = sjson.SetBytes(payload, "reasoning.effort", "xhigh")
-		}
-	}
-	return payload
-}
-
 func tokenizerForCodexModel(model string) (tokenizer.Codec, error) {
 	sanitized := strings.ToLower(strings.TrimSpace(model))
 	switch {

internal/runtime/executor/gemini_executor.go

@@ -75,6 +75,8 @@ func (e *GeminiExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
 
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	// Official Gemini API via API key or OAuth bearer
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini")
@@ -85,6 +87,7 @@ func (e *GeminiExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	body = util.StripThinkingConfigIfUnsupported(req.Model, body)
 	body = fixGeminiImageAspectRatio(req.Model, body)
 	body = applyPayloadConfig(e.cfg, req.Model, body)
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 
 	action := "generateContent"
 	if req.Metadata != nil {
@@ -93,7 +96,7 @@ func (e *GeminiExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 		}
 	}
 	baseURL := resolveGeminiBaseURL(auth)
-	url := fmt.Sprintf("%s/%s/models/%s:%s", baseURL, glAPIVersion, req.Model, action)
+	url := fmt.Sprintf("%s/%s/models/%s:%s", baseURL, glAPIVersion, upstreamModel, action)
 	if opts.Alt != "" && action != "countTokens" {
 		url = url + fmt.Sprintf("?$alt=%s", opts.Alt)
 	}
@@ -167,6 +170,8 @@ func (e *GeminiExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
 
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
@@ -176,9 +181,10 @@ func (e *GeminiExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 	body = util.StripThinkingConfigIfUnsupported(req.Model, body)
 	body = fixGeminiImageAspectRatio(req.Model, body)
 	body = applyPayloadConfig(e.cfg, req.Model, body)
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 
 	baseURL := resolveGeminiBaseURL(auth)
-	url := fmt.Sprintf("%s/%s/models/%s:%s", baseURL, glAPIVersion, req.Model, "streamGenerateContent")
+	url := fmt.Sprintf("%s/%s/models/%s:%s", baseURL, glAPIVersion, upstreamModel, "streamGenerateContent")
 	if opts.Alt == "" {
 		url = url + "?alt=sse"
 	} else {

internal/runtime/executor/gemini_vertex_executor.go

@@ -105,10 +105,12 @@ func (e *GeminiVertexExecutor) CountTokens(ctx context.Context, auth *cliproxyau
 
 // countTokensWithServiceAccount handles token counting using service account credentials.
 func (e *GeminiVertexExecutor) countTokensWithServiceAccount(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options, projectID, location string, saJSON []byte) (cliproxyexecutor.Response, error) {
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini")
 	translatedReq := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
-	if budgetOverride, includeOverride, ok := util.GeminiThinkingFromMetadata(req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
+	if budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
 		if budgetOverride != nil {
 			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
 			budgetOverride = &norm
@@ -117,13 +119,14 @@ func (e *GeminiVertexExecutor) countTokensWithServiceAccount(ctx context.Context
 	}
 	translatedReq = util.StripThinkingConfigIfUnsupported(req.Model, translatedReq)
 	translatedReq = fixGeminiImageAspectRatio(req.Model, translatedReq)
+	translatedReq, _ = sjson.SetBytes(translatedReq, "model", upstreamModel)
 	respCtx := context.WithValue(ctx, "alt", opts.Alt)
 	translatedReq, _ = sjson.DeleteBytes(translatedReq, "tools")
 	translatedReq, _ = sjson.DeleteBytes(translatedReq, "generationConfig")
 	translatedReq, _ = sjson.DeleteBytes(translatedReq, "safetySettings")
 
 	baseURL := vertexBaseURL(location)
-	url := fmt.Sprintf("%s/%s/projects/%s/locations/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, projectID, location, req.Model, "countTokens")
+	url := fmt.Sprintf("%s/%s/projects/%s/locations/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, projectID, location, upstreamModel, "countTokens")
 
 	httpReq, errNewReq := http.NewRequestWithContext(respCtx, http.MethodPost, url, bytes.NewReader(translatedReq))
 	if errNewReq != nil {
@@ -191,10 +194,12 @@ func (e *GeminiVertexExecutor) countTokensWithServiceAccount(ctx context.Context
 
 // countTokensWithAPIKey handles token counting using API key credentials.
 func (e *GeminiVertexExecutor) countTokensWithAPIKey(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options, apiKey, baseURL string) (cliproxyexecutor.Response, error) {
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini")
 	translatedReq := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
-	if budgetOverride, includeOverride, ok := util.GeminiThinkingFromMetadata(req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
+	if budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
 		if budgetOverride != nil {
 			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
 			budgetOverride = &norm
@@ -203,6 +208,7 @@ func (e *GeminiVertexExecutor) countTokensWithAPIKey(ctx context.Context, auth *
 	}
 	translatedReq = util.StripThinkingConfigIfUnsupported(req.Model, translatedReq)
 	translatedReq = fixGeminiImageAspectRatio(req.Model, translatedReq)
+	translatedReq, _ = sjson.SetBytes(translatedReq, "model", upstreamModel)
 	respCtx := context.WithValue(ctx, "alt", opts.Alt)
 	translatedReq, _ = sjson.DeleteBytes(translatedReq, "tools")
 	translatedReq, _ = sjson.DeleteBytes(translatedReq, "generationConfig")
@@ -286,10 +292,12 @@ func (e *GeminiVertexExecutor) executeWithServiceAccount(ctx context.Context, au
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
 
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
-	if budgetOverride, includeOverride, ok := util.GeminiThinkingFromMetadata(req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
+	if budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
 		if budgetOverride != nil {
 			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
 			budgetOverride = &norm
@@ -301,6 +309,7 @@ func (e *GeminiVertexExecutor) executeWithServiceAccount(ctx context.Context, au
 	body = util.StripThinkingConfigIfUnsupported(req.Model, body)
 	body = fixGeminiImageAspectRatio(req.Model, body)
 	body = applyPayloadConfig(e.cfg, req.Model, body)
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 
 	action := "generateContent"
 	if req.Metadata != nil {
@@ -309,7 +318,7 @@ func (e *GeminiVertexExecutor) executeWithServiceAccount(ctx context.Context, au
 		}
 	}
 	baseURL := vertexBaseURL(location)
-	url := fmt.Sprintf("%s/%s/projects/%s/locations/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, projectID, location, req.Model, action)
+	url := fmt.Sprintf("%s/%s/projects/%s/locations/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, projectID, location, upstreamModel, action)
 	if opts.Alt != "" && action != "countTokens" {
 		url = url + fmt.Sprintf("?$alt=%s", opts.Alt)
 	}
@@ -383,10 +392,12 @@ func (e *GeminiVertexExecutor) executeWithAPIKey(ctx context.Context, auth *clip
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
 
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
-	if budgetOverride, includeOverride, ok := util.GeminiThinkingFromMetadata(req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
+	if budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
 		if budgetOverride != nil {
 			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
 			budgetOverride = &norm
@@ -398,6 +409,7 @@ func (e *GeminiVertexExecutor) executeWithAPIKey(ctx context.Context, auth *clip
 	body = util.StripThinkingConfigIfUnsupported(req.Model, body)
 	body = fixGeminiImageAspectRatio(req.Model, body)
 	body = applyPayloadConfig(e.cfg, req.Model, body)
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 
 	action := "generateContent"
 	if req.Metadata != nil {
@@ -410,7 +422,7 @@ func (e *GeminiVertexExecutor) executeWithAPIKey(ctx context.Context, auth *clip
 	if baseURL == "" {
 		baseURL = "https://generativelanguage.googleapis.com"
 	}
-	url := fmt.Sprintf("%s/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, req.Model, action)
+	url := fmt.Sprintf("%s/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, upstreamModel, action)
 	if opts.Alt != "" && action != "countTokens" {
 		url = url + fmt.Sprintf("?$alt=%s", opts.Alt)
 	}
@@ -481,10 +493,12 @@ func (e *GeminiVertexExecutor) executeStreamWithServiceAccount(ctx context.Conte
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
 
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
-	if budgetOverride, includeOverride, ok := util.GeminiThinkingFromMetadata(req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
+	if budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
 		if budgetOverride != nil {
 			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
 			budgetOverride = &norm
@@ -496,9 +510,10 @@ func (e *GeminiVertexExecutor) executeStreamWithServiceAccount(ctx context.Conte
 	body = util.StripThinkingConfigIfUnsupported(req.Model, body)
 	body = fixGeminiImageAspectRatio(req.Model, body)
 	body = applyPayloadConfig(e.cfg, req.Model, body)
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 
 	baseURL := vertexBaseURL(location)
-	url := fmt.Sprintf("%s/%s/projects/%s/locations/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, projectID, location, req.Model, "streamGenerateContent")
+	url := fmt.Sprintf("%s/%s/projects/%s/locations/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, projectID, location, upstreamModel, "streamGenerateContent")
 	if opts.Alt == "" {
 		url = url + "?alt=sse"
 	} else {
@@ -595,10 +610,12 @@ func (e *GeminiVertexExecutor) executeStreamWithAPIKey(ctx context.Context, auth
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
 
+	upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata)
+
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
-	if budgetOverride, includeOverride, ok := util.GeminiThinkingFromMetadata(req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
+	if budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
 		if budgetOverride != nil {
 			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
 			budgetOverride = &norm
@@ -610,12 +627,13 @@ func (e *GeminiVertexExecutor) executeStreamWithAPIKey(ctx context.Context, auth
 	body = util.StripThinkingConfigIfUnsupported(req.Model, body)
 	body = fixGeminiImageAspectRatio(req.Model, body)
 	body = applyPayloadConfig(e.cfg, req.Model, body)
+	body, _ = sjson.SetBytes(body, "model", upstreamModel)
 
 	// For API key auth, use simpler URL format without project/location
 	if baseURL == "" {
 		baseURL = "https://generativelanguage.googleapis.com"
 	}
-	url := fmt.Sprintf("%s/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, req.Model, "streamGenerateContent")
+	url := fmt.Sprintf("%s/%s/publishers/google/models/%s:%s", baseURL, vertexAPIVersion, upstreamModel, "streamGenerateContent")
 	if opts.Alt == "" {
 		url = url + "?alt=sse"
 	} else {

internal/runtime/executor/iflow_executor.go

@@ -57,6 +57,10 @@ func (e *IFlowExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, re
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("openai")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
+	body = applyReasoningEffortMetadataChatCompletions(body, req.Metadata, req.Model)
+	if upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata); upstreamModel != "" {
+		body, _ = sjson.SetBytes(body, "model", upstreamModel)
+	}
 	body = applyPayloadConfig(e.cfg, req.Model, body)
 
 	endpoint := strings.TrimSuffix(baseURL, "/") + iflowDefaultEndpoint
@@ -139,6 +143,10 @@ func (e *IFlowExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Au
 	to := sdktranslator.FromString("openai")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
 
+	body = applyReasoningEffortMetadataChatCompletions(body, req.Metadata, req.Model)
+	if upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata); upstreamModel != "" {
+		body, _ = sjson.SetBytes(body, "model", upstreamModel)
+	}
 	// Ensure tools array exists to avoid provider quirks similar to Qwen's behaviour.
 	toolsResult := gjson.GetBytes(body, "tools")
 	if toolsResult.Exists() && toolsResult.IsArray() && len(toolsResult.Array()) == 0 {

internal/runtime/executor/openai_compat_executor.go

@@ -58,6 +58,10 @@ func (e *OpenAICompatExecutor) Execute(ctx context.Context, auth *cliproxyauth.A
 		translated = e.overrideModel(translated, modelOverride)
 	}
 	translated = applyPayloadConfigWithRoot(e.cfg, req.Model, to.String(), "", translated)
+	translated = applyReasoningEffortMetadataChatCompletions(translated, req.Metadata, req.Model)
+	if upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata); upstreamModel != "" {
+		translated, _ = sjson.SetBytes(translated, "model", upstreamModel)
+	}
 
 	url := strings.TrimSuffix(baseURL, "/") + "/chat/completions"
 	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(translated))
@@ -143,6 +147,10 @@ func (e *OpenAICompatExecutor) ExecuteStream(ctx context.Context, auth *cliproxy
 		translated = e.overrideModel(translated, modelOverride)
 	}
 	translated = applyPayloadConfigWithRoot(e.cfg, req.Model, to.String(), "", translated)
+	translated = applyReasoningEffortMetadataChatCompletions(translated, req.Metadata, req.Model)
+	if upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata); upstreamModel != "" {
+		translated, _ = sjson.SetBytes(translated, "model", upstreamModel)
+	}
 
 	url := strings.TrimSuffix(baseURL, "/") + "/chat/completions"
 	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(translated))

internal/runtime/executor/payload_helpers.go

@@ -12,8 +12,8 @@ import (
 // applyThinkingMetadata applies thinking config from model suffix metadata (e.g., -reasoning, -thinking-N)
 // for standard Gemini format payloads. It normalizes the budget when the model supports thinking.
 func applyThinkingMetadata(payload []byte, metadata map[string]any, model string) []byte {
-	budgetOverride, includeOverride, ok := util.GeminiThinkingFromMetadata(metadata)
+	budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(model, metadata)
-	if !ok {
+	if !ok || (budgetOverride == nil && includeOverride == nil) {
 		return payload
 	}
 	if !util.ModelSupportsThinking(model) {
@@ -29,17 +29,60 @@ func applyThinkingMetadata(payload []byte, metadata map[string]any, model string
 // applyThinkingMetadataCLI applies thinking config from model suffix metadata (e.g., -reasoning, -thinking-N)
 // for Gemini CLI format payloads (nested under "request"). It normalizes the budget when the model supports thinking.
 func applyThinkingMetadataCLI(payload []byte, metadata map[string]any, model string) []byte {
-	budgetOverride, includeOverride, ok := util.GeminiThinkingFromMetadata(metadata)
+	budgetOverride, includeOverride, ok := util.ResolveThinkingConfigFromMetadata(model, metadata)
-	if !ok {
+	if !ok || (budgetOverride == nil && includeOverride == nil) {
 		return payload
 	}
-	if budgetOverride != nil && util.ModelSupportsThinking(model) {
+	if !util.ModelSupportsThinking(model) {
+		return payload
+	}
+	if budgetOverride != nil {
 		norm := util.NormalizeThinkingBudget(model, *budgetOverride)
 		budgetOverride = &norm
 	}
 	return util.ApplyGeminiCLIThinkingConfig(payload, budgetOverride, includeOverride)
 }
 
+// applyReasoningEffortMetadata applies reasoning effort overrides (reasoning.effort) when present in metadata.
+// It avoids overwriting an existing reasoning.effort field and only applies to models that support thinking.
+func applyReasoningEffortMetadata(payload []byte, metadata map[string]any, model string) []byte {
+	if len(metadata) == 0 {
+		return payload
+	}
+	if !util.ModelSupportsThinking(model) {
+		return payload
+	}
+	if gjson.GetBytes(payload, "reasoning.effort").Exists() {
+		return payload
+	}
+	if effort, ok := util.ReasoningEffortFromMetadata(metadata); ok && effort != "" {
+		if updated, err := sjson.SetBytes(payload, "reasoning.effort", effort); err == nil {
+			return updated
+		}
+	}
+	return payload
+}
+
+// applyReasoningEffortMetadataChatCompletions applies reasoning_effort (OpenAI chat completions field)
+// when present in metadata. It avoids overwriting an existing reasoning_effort field.
+func applyReasoningEffortMetadataChatCompletions(payload []byte, metadata map[string]any, model string) []byte {
+	if len(metadata) == 0 {
+		return payload
+	}
+	if !util.ModelSupportsThinking(model) {
+		return payload
+	}
+	if gjson.GetBytes(payload, "reasoning_effort").Exists() {
+		return payload
+	}
+	if effort, ok := util.ReasoningEffortFromMetadata(metadata); ok && effort != "" {
+		if updated, err := sjson.SetBytes(payload, "reasoning_effort", effort); err == nil {
+			return updated
+		}
+	}
+	return payload
+}
+
 // applyPayloadConfig applies payload default and override rules from configuration
 // to the given JSON payload for the specified model.
 // Defaults only fill missing fields, while overrides always overwrite existing values.

internal/runtime/executor/qwen_executor.go

@@ -12,6 +12,7 @@ import (
 
 	qwenauth "github.com/router-for-me/CLIProxyAPI/v6/internal/auth/qwen"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
 	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
 	cliproxyexecutor "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/executor"
 	sdktranslator "github.com/router-for-me/CLIProxyAPI/v6/sdk/translator"
@@ -50,6 +51,10 @@ func (e *QwenExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, req
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("openai")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
+	body = applyReasoningEffortMetadataChatCompletions(body, req.Metadata, req.Model)
+	if upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata); upstreamModel != "" {
+		body, _ = sjson.SetBytes(body, "model", upstreamModel)
+	}
 	body = applyPayloadConfig(e.cfg, req.Model, body)
 
 	url := strings.TrimSuffix(baseURL, "/") + "/chat/completions"
@@ -121,6 +126,10 @@ func (e *QwenExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Aut
 	to := sdktranslator.FromString("openai")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
 
+	body = applyReasoningEffortMetadataChatCompletions(body, req.Metadata, req.Model)
+	if upstreamModel := util.ResolveOriginalModel(req.Model, req.Metadata); upstreamModel != "" {
+		body, _ = sjson.SetBytes(body, "model", upstreamModel)
+	}
 	toolsResult := gjson.GetBytes(body, "tools")
 	// I'm addressing the Qwen3 "poisoning" issue, which is caused by the model needing a tool to be defined. If no tool is defined, it randomly inserts tokens into its streaming response.
 	// This will have no real consequences. It's just to scare Qwen3.

internal/util/gemini_thinking.go

@@ -1,8 +1,6 @@
 package util
 
 import (
-	"encoding/json"
-	"strconv"
 	"strings"
 
 	"github.com/tidwall/gjson"
@@ -15,80 +13,6 @@ const (
 	GeminiOriginalModelMetadataKey   = "gemini_original_model"
 )
 
-func ParseGeminiThinkingSuffix(model string) (string, *int, *bool, bool) {
-	if model == "" {
-		return model, nil, nil, false
-	}
-	lower := strings.ToLower(model)
-	if !strings.HasPrefix(lower, "gemini-") {
-		return model, nil, nil, false
-	}
-
-	if strings.HasSuffix(lower, "-nothinking") {
-		base := model[:len(model)-len("-nothinking")]
-		budgetValue := 0
-		if strings.HasPrefix(lower, "gemini-2.5-pro") {
-			budgetValue = 128
-		}
-		include := false
-		return base, &budgetValue, &include, true
-	}
-
-	// Handle "-reasoning" suffix: enables thinking with dynamic budget (-1)
-	// Maps: gemini-2.5-flash-reasoning -> gemini-2.5-flash with thinkingBudget=-1
-	if strings.HasSuffix(lower, "-reasoning") {
-		base := model[:len(model)-len("-reasoning")]
-		budgetValue := -1 // Dynamic budget
-		include := true
-		return base, &budgetValue, &include, true
-	}
-
-	idx := strings.LastIndex(lower, "-thinking-")
-	if idx == -1 {
-		return model, nil, nil, false
-	}
-
-	digits := model[idx+len("-thinking-"):]
-	if digits == "" {
-		return model, nil, nil, false
-	}
-	end := len(digits)
-	for i := 0; i < len(digits); i++ {
-		if digits[i] < '0' || digits[i] > '9' {
-			end = i
-			break
-		}
-	}
-	if end == 0 {
-		return model, nil, nil, false
-	}
-	valueStr := digits[:end]
-	value, err := strconv.Atoi(valueStr)
-	if err != nil {
-		return model, nil, nil, false
-	}
-	base := model[:idx]
-	budgetValue := value
-	return base, &budgetValue, nil, true
-}
-
-func NormalizeGeminiThinkingModel(modelName string) (string, map[string]any) {
-	baseModel, budget, include, matched := ParseGeminiThinkingSuffix(modelName)
-	if !matched {
-		return baseModel, nil
-	}
-	metadata := map[string]any{
-		GeminiOriginalModelMetadataKey: modelName,
-	}
-	if budget != nil {
-		metadata[GeminiThinkingBudgetMetadataKey] = *budget
-	}
-	if include != nil {
-		metadata[GeminiIncludeThoughtsMetadataKey] = *include
-	}
-	return baseModel, metadata
-}
-
 func ApplyGeminiThinkingConfig(body []byte, budget *int, includeThoughts *bool) []byte {
 	if budget == nil && includeThoughts == nil {
 		return body
@@ -133,80 +57,6 @@ func ApplyGeminiCLIThinkingConfig(body []byte, budget *int, includeThoughts *boo
 	return updated
 }
 
-func GeminiThinkingFromMetadata(metadata map[string]any) (*int, *bool, bool) {
-	if len(metadata) == 0 {
-		return nil, nil, false
-	}
-	var (
-		budgetPtr  *int
-		includePtr *bool
-		matched    bool
-	)
-	if rawBudget, ok := metadata[GeminiThinkingBudgetMetadataKey]; ok {
-		switch v := rawBudget.(type) {
-		case int:
-			budget := v
-			budgetPtr = &budget
-			matched = true
-		case int32:
-			budget := int(v)
-			budgetPtr = &budget
-			matched = true
-		case int64:
-			budget := int(v)
-			budgetPtr = &budget
-			matched = true
-		case float64:
-			budget := int(v)
-			budgetPtr = &budget
-			matched = true
-		case json.Number:
-			if val, err := v.Int64(); err == nil {
-				budget := int(val)
-				budgetPtr = &budget
-				matched = true
-			}
-		}
-	}
-	if rawInclude, ok := metadata[GeminiIncludeThoughtsMetadataKey]; ok {
-		switch v := rawInclude.(type) {
-		case bool:
-			include := v
-			includePtr = &include
-			matched = true
-		case string:
-			if parsed, err := strconv.ParseBool(v); err == nil {
-				include := parsed
-				includePtr = &include
-				matched = true
-			}
-		case json.Number:
-			if val, err := v.Int64(); err == nil {
-				include := val != 0
-				includePtr = &include
-				matched = true
-			}
-		case int:
-			include := v != 0
-			includePtr = &include
-			matched = true
-		case int32:
-			include := v != 0
-			includePtr = &include
-			matched = true
-		case int64:
-			include := v != 0
-			includePtr = &include
-			matched = true
-		case float64:
-			include := v != 0
-			includePtr = &include
-			matched = true
-		}
-	}
-	return budgetPtr, includePtr, matched
-}
-
 // modelsWithDefaultThinking lists models that should have thinking enabled by default
 // when no explicit thinkingConfig is provided.
 var modelsWithDefaultThinking = map[string]bool{

internal/util/thinking_suffix.go

@@ -0,0 +1,327 @@
+package util
+
+import (
+	"encoding/json"
+	"strconv"
+	"strings"
+)
+
+const (
+	ThinkingBudgetMetadataKey          = "thinking_budget"
+	ThinkingIncludeThoughtsMetadataKey = "thinking_include_thoughts"
+	ReasoningEffortMetadataKey         = "reasoning_effort"
+	ThinkingOriginalModelMetadataKey   = "thinking_original_model"
+)
+
+// NormalizeThinkingModel parses dynamic thinking suffixes on model names and returns
+// the normalized base model with extracted metadata. Supported patterns:
+//   - "-thinking-<number>" extracts a numeric budget
+//   - "-thinking-<level>" extracts a reasoning effort level (minimal/low/medium/high/xhigh/auto/none)
+//   - "-thinking" maps to a default reasoning effort of "medium"
+//   - "-reasoning" maps to dynamic budget (-1) and include_thoughts=true
+//   - "-nothinking" maps to budget=0 and include_thoughts=false
+func NormalizeThinkingModel(modelName string) (string, map[string]any) {
+	if modelName == "" {
+		return modelName, nil
+	}
+
+	lower := strings.ToLower(modelName)
+	baseModel := modelName
+
+	var (
+		budgetOverride  *int
+		includeThoughts *bool
+		reasoningEffort *string
+		matched         bool
+	)
+
+	switch {
+	case strings.HasSuffix(lower, "-nothinking"):
+		baseModel = modelName[:len(modelName)-len("-nothinking")]
+		budget := 0
+		include := false
+		budgetOverride = &budget
+		includeThoughts = &include
+		matched = true
+	case strings.HasSuffix(lower, "-reasoning"):
+		baseModel = modelName[:len(modelName)-len("-reasoning")]
+		budget := -1
+		include := true
+		budgetOverride = &budget
+		includeThoughts = &include
+		matched = true
+	default:
+		if idx := strings.LastIndex(lower, "-thinking-"); idx != -1 {
+			value := modelName[idx+len("-thinking-"):]
+			if value != "" {
+				if parsed, ok := parseIntPrefix(value); ok {
+					baseModel = modelName[:idx]
+					budgetOverride = &parsed
+					matched = true
+				} else if effort, okEffort := normalizeReasoningEffort(value); okEffort {
+					baseModel = modelName[:idx]
+					reasoningEffort = &effort
+					matched = true
+				}
+			}
+		} else if strings.HasSuffix(lower, "-thinking") {
+			baseModel = modelName[:len(modelName)-len("-thinking")]
+			effort := "medium"
+			reasoningEffort = &effort
+			matched = true
+		}
+	}
+
+	if !matched {
+		return baseModel, nil
+	}
+
+	metadata := map[string]any{
+		ThinkingOriginalModelMetadataKey: modelName,
+	}
+	if budgetOverride != nil {
+		metadata[ThinkingBudgetMetadataKey] = *budgetOverride
+	}
+	if includeThoughts != nil {
+		metadata[ThinkingIncludeThoughtsMetadataKey] = *includeThoughts
+	}
+	if reasoningEffort != nil {
+		metadata[ReasoningEffortMetadataKey] = *reasoningEffort
+	}
+	return baseModel, metadata
+}
+
+// ThinkingFromMetadata extracts thinking overrides from metadata produced by NormalizeThinkingModel.
+// It accepts both the new generic keys and legacy Gemini-specific keys.
+func ThinkingFromMetadata(metadata map[string]any) (*int, *bool, *string, bool) {
+	if len(metadata) == 0 {
+		return nil, nil, nil, false
+	}
+
+	var (
+		budgetPtr  *int
+		includePtr *bool
+		effortPtr  *string
+		matched    bool
+	)
+
+	readBudget := func(key string) {
+		if budgetPtr != nil {
+			return
+		}
+		if raw, ok := metadata[key]; ok {
+			if v, okNumber := parseNumberToInt(raw); okNumber {
+				budget := v
+				budgetPtr = &budget
+				matched = true
+			}
+		}
+	}
+
+	readInclude := func(key string) {
+		if includePtr != nil {
+			return
+		}
+		if raw, ok := metadata[key]; ok {
+			switch v := raw.(type) {
+			case bool:
+				val := v
+				includePtr = &val
+				matched = true
+			case *bool:
+				if v != nil {
+					val := *v
+					includePtr = &val
+					matched = true
+				}
+			}
+		}
+	}
+
+	readEffort := func(key string) {
+		if effortPtr != nil {
+			return
+		}
+		if raw, ok := metadata[key]; ok {
+			if val, okStr := raw.(string); okStr && strings.TrimSpace(val) != "" {
+				normalized := strings.ToLower(strings.TrimSpace(val))
+				effortPtr = &normalized
+				matched = true
+			}
+		}
+	}
+
+	readBudget(ThinkingBudgetMetadataKey)
+	readBudget(GeminiThinkingBudgetMetadataKey)
+	readInclude(ThinkingIncludeThoughtsMetadataKey)
+	readInclude(GeminiIncludeThoughtsMetadataKey)
+	readEffort(ReasoningEffortMetadataKey)
+	readEffort("reasoning.effort")
+
+	return budgetPtr, includePtr, effortPtr, matched
+}
+
+// ResolveThinkingConfigFromMetadata derives thinking budget/include overrides,
+// converting reasoning effort strings into budgets when possible.
+func ResolveThinkingConfigFromMetadata(model string, metadata map[string]any) (*int, *bool, bool) {
+	budget, include, effort, matched := ThinkingFromMetadata(metadata)
+	if !matched {
+		return nil, nil, false
+	}
+
+	if budget == nil && effort != nil {
+		if derived, ok := ThinkingEffortToBudget(model, *effort); ok {
+			budget = &derived
+		}
+	}
+	return budget, include, budget != nil || include != nil || effort != nil
+}
+
+// ReasoningEffortFromMetadata resolves a reasoning effort string from metadata,
+// inferring "auto" and "none" when budgets request dynamic or disabled thinking.
+func ReasoningEffortFromMetadata(metadata map[string]any) (string, bool) {
+	budget, include, effort, matched := ThinkingFromMetadata(metadata)
+	if !matched {
+		return "", false
+	}
+	if effort != nil && *effort != "" {
+		return *effort, true
+	}
+	if budget != nil {
+		switch *budget {
+		case -1:
+			return "auto", true
+		case 0:
+			return "none", true
+		}
+	}
+	if include != nil && !*include {
+		return "none", true
+	}
+	return "", true
+}
+
+// ThinkingEffortToBudget maps reasoning effort levels to approximate budgets,
+// clamping the result to the model's supported range.
+func ThinkingEffortToBudget(model, effort string) (int, bool) {
+	if effort == "" {
+		return 0, false
+	}
+	switch strings.ToLower(effort) {
+	case "none":
+		return 0, true
+	case "auto":
+		return NormalizeThinkingBudget(model, -1), true
+	case "minimal":
+		return NormalizeThinkingBudget(model, 512), true
+	case "low":
+		return NormalizeThinkingBudget(model, 1024), true
+	case "medium":
+		return NormalizeThinkingBudget(model, 8192), true
+	case "high":
+		return NormalizeThinkingBudget(model, 24576), true
+	case "xhigh":
+		return NormalizeThinkingBudget(model, 32768), true
+	default:
+		return 0, false
+	}
+}
+
+// ResolveOriginalModel returns the original model name stored in metadata (if present),
+// otherwise falls back to the provided model.
+func ResolveOriginalModel(model string, metadata map[string]any) string {
+	normalize := func(name string) string {
+		if name == "" {
+			return ""
+		}
+		if base, _ := NormalizeThinkingModel(name); base != "" {
+			return base
+		}
+		return strings.TrimSpace(name)
+	}
+
+	if metadata != nil {
+		if v, ok := metadata[ThinkingOriginalModelMetadataKey]; ok {
+			if s, okStr := v.(string); okStr && strings.TrimSpace(s) != "" {
+				if base := normalize(s); base != "" {
+					return base
+				}
+			}
+		}
+		if v, ok := metadata[GeminiOriginalModelMetadataKey]; ok {
+			if s, okStr := v.(string); okStr && strings.TrimSpace(s) != "" {
+				if base := normalize(s); base != "" {
+					return base
+				}
+			}
+		}
+	}
+	// Fallback: try to re-normalize the model name when metadata was dropped.
+	if base := normalize(model); base != "" {
+		return base
+	}
+	return model
+}
+
+func parseIntPrefix(value string) (int, bool) {
+	if value == "" {
+		return 0, false
+	}
+	digits := strings.TrimLeft(value, "-")
+	if digits == "" {
+		return 0, false
+	}
+	end := len(digits)
+	for i := 0; i < len(digits); i++ {
+		if digits[i] < '0' || digits[i] > '9' {
+			end = i
+			break
+		}
+	}
+	if end == 0 {
+		return 0, false
+	}
+	val, err := strconv.Atoi(digits[:end])
+	if err != nil {
+		return 0, false
+	}
+	return val, true
+}
+
+func parseNumberToInt(raw any) (int, bool) {
+	switch v := raw.(type) {
+	case int:
+		return v, true
+	case int32:
+		return int(v), true
+	case int64:
+		return int(v), true
+	case float64:
+		return int(v), true
+	case json.Number:
+		if val, err := v.Int64(); err == nil {
+			return int(val), true
+		}
+	case string:
+		if strings.TrimSpace(v) == "" {
+			return 0, false
+		}
+		if parsed, err := strconv.Atoi(strings.TrimSpace(v)); err == nil {
+			return parsed, true
+		}
+	}
+	return 0, false
+}
+
+func normalizeReasoningEffort(value string) (string, bool) {
+	if value == "" {
+		return "", false
+	}
+	effort := strings.ToLower(strings.TrimSpace(value))
+	switch effort {
+	case "minimal", "low", "medium", "high", "xhigh", "auto", "none":
+		return effort, true
+	default:
+		return "", false
+	}
+}

sdk/api/handlers/handlers.go

@@ -323,18 +323,32 @@ func (h *BaseAPIHandler) getRequestDetails(modelName string) (providers []string
 
 	providerName, extractedModelName, isDynamic := h.parseDynamicModel(resolvedModelName)
 
-	// First, normalize the model name to handle suffixes like "-thinking-128"
+	targetModelName := resolvedModelName
-	// This needs to happen before determining the provider for non-dynamic models.
+	if isDynamic {
-	normalizedModel, metadata = normalizeModelMetadata(resolvedModelName)
+		targetModelName = extractedModelName
+	}
+
+	// Normalize the model name to handle dynamic thinking suffixes before determining the provider.
+	normalizedModel, metadata = normalizeModelMetadata(targetModelName)
 
 	if isDynamic {
 		providers = []string{providerName}
-		// For dynamic models, the extractedModelName is already normalized by parseDynamicModel
-		// so we use it as the final normalizedModel.
-		normalizedModel = extractedModelName
 	} else {
 		// For non-dynamic models, use the normalizedModel to get the provider name.
 		providers = util.GetProviderName(normalizedModel)
+		if len(providers) == 0 && metadata != nil {
+			if originalRaw, ok := metadata[util.ThinkingOriginalModelMetadataKey]; ok {
+				if originalModel, okStr := originalRaw.(string); okStr {
+					originalModel = strings.TrimSpace(originalModel)
+					if originalModel != "" && !strings.EqualFold(originalModel, normalizedModel) {
+						if altProviders := util.GetProviderName(originalModel); len(altProviders) > 0 {
+							providers = altProviders
+							normalizedModel = originalModel
+						}
+					}
+				}
+			}
+		}
 	}
 
 	if len(providers) == 0 {
@@ -382,7 +396,7 @@ func cloneBytes(src []byte) []byte {
 }
 
 func normalizeModelMetadata(modelName string) (string, map[string]any) {
-	return util.NormalizeGeminiThinkingModel(modelName)
+	return util.NormalizeThinkingModel(modelName)
 }
 
 func cloneMetadata(src map[string]any) map[string]any {