feat(vertex): add usage source resolution for Vertex projects

Extend `resolveUsageSource` to support Vertex projects by extracting and normalizing `project_id` or `project` from the metadata for accurate source resolution.

internal/api/handlers/management/auth_files.go

@@ -508,6 +508,10 @@ func (h *Handler) DeleteAuthFile(c *gin.Context) {
 				}
 			}
 			if err = os.Remove(full); err == nil {
+				if errDel := h.deleteTokenRecord(ctx, full); errDel != nil {
+					c.JSON(500, gin.H{"error": errDel.Error()})
+					return
+				}
 				deleted++
 				h.disableAuth(ctx, full)
 			}
@@ -534,10 +538,32 @@ func (h *Handler) DeleteAuthFile(c *gin.Context) {
 		}
 		return
 	}
+	if err := h.deleteTokenRecord(ctx, full); err != nil {
+		c.JSON(500, gin.H{"error": err.Error()})
+		return
+	}
 	h.disableAuth(ctx, full)
 	c.JSON(200, gin.H{"status": "ok"})
 }
 
+func (h *Handler) authIDForPath(path string) string {
+	path = strings.TrimSpace(path)
+	if path == "" {
+		return ""
+	}
+	if h == nil || h.cfg == nil {
+		return path
+	}
+	authDir := strings.TrimSpace(h.cfg.AuthDir)
+	if authDir == "" {
+		return path
+	}
+	if rel, err := filepath.Rel(authDir, path); err == nil && rel != "" {
+		return rel
+	}
+	return path
+}
+
 func (h *Handler) registerAuthFromFile(ctx context.Context, path string, data []byte) error {
 	if h.authManager == nil {
 		return nil
@@ -566,13 +592,18 @@ func (h *Handler) registerAuthFromFile(ctx context.Context, path string, data []
 	}
 	lastRefresh, hasLastRefresh := extractLastRefreshTimestamp(metadata)
 
+	authID := h.authIDForPath(path)
+	if authID == "" {
+		authID = path
+	}
 	attr := map[string]string{
 		"path":   path,
 		"source": path,
 	}
 	auth := &coreauth.Auth{
-		ID:         path,
+		ID:         authID,
 		Provider:   provider,
+		FileName:   filepath.Base(path),
 		Label:      label,
 		Status:     coreauth.StatusActive,
 		Attributes: attr,
@@ -583,7 +614,7 @@ func (h *Handler) registerAuthFromFile(ctx context.Context, path string, data []
 	if hasLastRefresh {
 		auth.LastRefreshedAt = lastRefresh
 	}
-	if existing, ok := h.authManager.GetByID(path); ok {
+	if existing, ok := h.authManager.GetByID(authID); ok {
 		auth.CreatedAt = existing.CreatedAt
 		if !hasLastRefresh {
 			auth.LastRefreshedAt = existing.LastRefreshedAt
@@ -598,10 +629,17 @@ func (h *Handler) registerAuthFromFile(ctx context.Context, path string, data []
 }
 
 func (h *Handler) disableAuth(ctx context.Context, id string) {
-	if h.authManager == nil || id == "" {
+	if h == nil || h.authManager == nil {
 		return
 	}
-	if auth, ok := h.authManager.GetByID(id); ok {
+	authID := h.authIDForPath(id)
+	if authID == "" {
+		authID = strings.TrimSpace(id)
+	}
+	if authID == "" {
+		return
+	}
+	if auth, ok := h.authManager.GetByID(authID); ok {
 		auth.Disabled = true
 		auth.Status = coreauth.StatusDisabled
 		auth.StatusMessage = "removed via management API"
@@ -610,9 +648,20 @@ func (h *Handler) disableAuth(ctx context.Context, id string) {
 	}
 }
 
-func (h *Handler) saveTokenRecord(ctx context.Context, record *coreauth.Auth) (string, error) {
-	if record == nil {
-		return "", fmt.Errorf("token record is nil")
+func (h *Handler) deleteTokenRecord(ctx context.Context, path string) error {
+	if strings.TrimSpace(path) == "" {
+		return fmt.Errorf("auth path is empty")
+	}
+	store := h.tokenStoreWithBaseDir()
+	if store == nil {
+		return fmt.Errorf("token store unavailable")
+	}
+	return store.Delete(ctx, path)
+}
+
+func (h *Handler) tokenStoreWithBaseDir() coreauth.Store {
+	if h == nil {
+		return nil
 	}
 	store := h.tokenStore
 	if store == nil {
@@ -624,6 +673,17 @@ func (h *Handler) saveTokenRecord(ctx context.Context, record *coreauth.Auth) (s
 			dirSetter.SetBaseDir(h.cfg.AuthDir)
 		}
 	}
+	return store
+}
+
+func (h *Handler) saveTokenRecord(ctx context.Context, record *coreauth.Auth) (string, error) {
+	if record == nil {
+		return "", fmt.Errorf("token record is nil")
+	}
+	store := h.tokenStoreWithBaseDir()
+	if store == nil {
+		return "", fmt.Errorf("token store unavailable")
+	}
 	return store.Save(ctx, record)
 }
 

internal/api/handlers/management/config_basic.go

@@ -28,7 +28,7 @@ func (h *Handler) GetConfigYAML(c *gin.Context) {
 		return
 	}
 	var node yaml.Node
-	if err := yaml.Unmarshal(data, &node); err != nil {
+	if err = yaml.Unmarshal(data, &node); err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": "parse_failed", "message": err.Error()})
 		return
 	}
@@ -41,17 +41,18 @@ func (h *Handler) GetConfigYAML(c *gin.Context) {
 }
 
 func WriteConfig(path string, data []byte) error {
+	data = config.NormalizeCommentIndentation(data)
 	f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
 	if err != nil {
 		return err
 	}
-	if _, err := f.Write(data); err != nil {
-		f.Close()
-		return err
+	if _, errWrite := f.Write(data); errWrite != nil {
+		_ = f.Close()
+		return errWrite
 	}
-	if err := f.Sync(); err != nil {
-		f.Close()
-		return err
+	if errSync := f.Sync(); errSync != nil {
+		_ = f.Close()
+		return errSync
 	}
 	return f.Close()
 }
@@ -63,7 +64,7 @@ func (h *Handler) PutConfigYAML(c *gin.Context) {
 		return
 	}
 	var cfg config.Config
-	if err := yaml.Unmarshal(body, &cfg); err != nil {
+	if err = yaml.Unmarshal(body, &cfg); err != nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid_yaml", "message": err.Error()})
 		return
 	}
@@ -75,18 +76,20 @@ func (h *Handler) PutConfigYAML(c *gin.Context) {
 		return
 	}
 	tempFile := tmpFile.Name()
-	if _, err := tmpFile.Write(body); err != nil {
-		tmpFile.Close()
-		os.Remove(tempFile)
-		c.JSON(http.StatusInternalServerError, gin.H{"error": "write_failed", "message": err.Error()})
+	if _, errWrite := tmpFile.Write(body); errWrite != nil {
+		_ = tmpFile.Close()
+		_ = os.Remove(tempFile)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "write_failed", "message": errWrite.Error()})
 		return
 	}
-	if err := tmpFile.Close(); err != nil {
-		os.Remove(tempFile)
-		c.JSON(http.StatusInternalServerError, gin.H{"error": "write_failed", "message": err.Error()})
+	if errClose := tmpFile.Close(); errClose != nil {
+		_ = os.Remove(tempFile)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "write_failed", "message": errClose.Error()})
 		return
 	}
-	defer os.Remove(tempFile)
+	defer func() {
+		_ = os.Remove(tempFile)
+	}()
 	_, err = config.LoadConfigOptional(tempFile, false)
 	if err != nil {
 		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "invalid_config", "message": err.Error()})
@@ -153,6 +156,14 @@ func (h *Handler) PutRequestLog(c *gin.Context) {
 	h.updateBoolField(c, func(v bool) { h.cfg.RequestLog = v })
 }
 
+// Websocket auth
+func (h *Handler) GetWebsocketAuth(c *gin.Context) {
+	c.JSON(200, gin.H{"ws-auth": h.cfg.WebsocketAuth})
+}
+func (h *Handler) PutWebsocketAuth(c *gin.Context) {
+	h.updateBoolField(c, func(v bool) { h.cfg.WebsocketAuth = v })
+}
+
 // Request retry
 func (h *Handler) GetRequestRetry(c *gin.Context) {
 	c.JSON(200, gin.H{"request-retry": h.cfg.RequestRetry})

internal/api/handlers/management/vertex_import.go

@@ -0,0 +1,156 @@
+package management
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/auth/vertex"
+	coreauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
+)
+
+// ImportVertexCredential handles uploading a Vertex service account JSON and saving it as an auth record.
+func (h *Handler) ImportVertexCredential(c *gin.Context) {
+	if h == nil || h.cfg == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "config unavailable"})
+		return
+	}
+	if h.cfg.AuthDir == "" {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "auth directory not configured"})
+		return
+	}
+
+	fileHeader, err := c.FormFile("file")
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "file required"})
+		return
+	}
+
+	file, err := fileHeader.Open()
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("failed to read file: %v", err)})
+		return
+	}
+	defer file.Close()
+
+	data, err := io.ReadAll(file)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("failed to read file: %v", err)})
+		return
+	}
+
+	var serviceAccount map[string]any
+	if err := json.Unmarshal(data, &serviceAccount); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid json", "message": err.Error()})
+		return
+	}
+
+	normalizedSA, err := vertex.NormalizeServiceAccountMap(serviceAccount)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid service account", "message": err.Error()})
+		return
+	}
+	serviceAccount = normalizedSA
+
+	projectID := strings.TrimSpace(valueAsString(serviceAccount["project_id"]))
+	if projectID == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "project_id missing"})
+		return
+	}
+	email := strings.TrimSpace(valueAsString(serviceAccount["client_email"]))
+
+	location := strings.TrimSpace(c.PostForm("location"))
+	if location == "" {
+		location = strings.TrimSpace(c.Query("location"))
+	}
+	if location == "" {
+		location = "us-central1"
+	}
+
+	fileName := fmt.Sprintf("vertex-%s.json", sanitizeVertexFilePart(projectID))
+	label := labelForVertex(projectID, email)
+	storage := &vertex.VertexCredentialStorage{
+		ServiceAccount: serviceAccount,
+		ProjectID:      projectID,
+		Email:          email,
+		Location:       location,
+		Type:           "vertex",
+	}
+	metadata := map[string]any{
+		"service_account": serviceAccount,
+		"project_id":      projectID,
+		"email":           email,
+		"location":        location,
+		"type":            "vertex",
+		"label":           label,
+	}
+	record := &coreauth.Auth{
+		ID:       fileName,
+		Provider: "vertex",
+		FileName: fileName,
+		Storage:  storage,
+		Label:    label,
+		Metadata: metadata,
+	}
+
+	ctx := context.Background()
+	if reqCtx := c.Request.Context(); reqCtx != nil {
+		ctx = reqCtx
+	}
+	savedPath, err := h.saveTokenRecord(ctx, record)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "save_failed", "message": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"status":     "ok",
+		"auth-file":  savedPath,
+		"project_id": projectID,
+		"email":      email,
+		"location":   location,
+	})
+}
+
+func valueAsString(v any) string {
+	if v == nil {
+		return ""
+	}
+	switch t := v.(type) {
+	case string:
+		return t
+	default:
+		return fmt.Sprint(t)
+	}
+}
+
+func sanitizeVertexFilePart(s string) string {
+	out := strings.TrimSpace(s)
+	replacers := []string{"/", "_", "\\", "_", ":", "_", " ", "-"}
+	for i := 0; i < len(replacers); i += 2 {
+		out = strings.ReplaceAll(out, replacers[i], replacers[i+1])
+	}
+	if out == "" {
+		return "vertex"
+	}
+	return out
+}
+
+func labelForVertex(projectID, email string) string {
+	p := strings.TrimSpace(projectID)
+	e := strings.TrimSpace(email)
+	if p != "" && e != "" {
+		return fmt.Sprintf("%s (%s)", p, e)
+	}
+	if p != "" {
+		return p
+	}
+	if e != "" {
+		return e
+	}
+	return "vertex"
+}

internal/api/server.go

@@ -484,6 +484,9 @@ func (s *Server) registerManagementRoutes() {
 		mgmt.GET("/request-log", s.mgmt.GetRequestLog)
 		mgmt.PUT("/request-log", s.mgmt.PutRequestLog)
 		mgmt.PATCH("/request-log", s.mgmt.PutRequestLog)
+		mgmt.GET("/ws-auth", s.mgmt.GetWebsocketAuth)
+		mgmt.PUT("/ws-auth", s.mgmt.PutWebsocketAuth)
+		mgmt.PATCH("/ws-auth", s.mgmt.PutWebsocketAuth)
 
 		mgmt.GET("/request-retry", s.mgmt.GetRequestRetry)
 		mgmt.PUT("/request-retry", s.mgmt.PutRequestRetry)
@@ -508,6 +511,7 @@ func (s *Server) registerManagementRoutes() {
 		mgmt.GET("/auth-files/download", s.mgmt.DownloadAuthFile)
 		mgmt.POST("/auth-files", s.mgmt.UploadAuthFile)
 		mgmt.DELETE("/auth-files", s.mgmt.DeleteAuthFile)
+		mgmt.POST("/vertex/import", s.mgmt.ImportVertexCredential)
 
 		mgmt.GET("/anthropic-auth-url", s.mgmt.RequestAnthropicToken)
 		mgmt.GET("/codex-auth-url", s.mgmt.RequestCodexToken)

internal/config/config.go

@@ -5,6 +5,7 @@
 package config
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"os"
@@ -462,13 +463,19 @@ func SaveConfigPreserveComments(configFile string, cfg *Config) error {
 		return err
 	}
 	defer func() { _ = f.Close() }()
-	enc := yaml.NewEncoder(f)
+	var buf bytes.Buffer
+	enc := yaml.NewEncoder(&buf)
 	enc.SetIndent(2)
 	if err = enc.Encode(&original); err != nil {
 		_ = enc.Close()
 		return err
 	}
-	return enc.Close()
+	if err = enc.Close(); err != nil {
+		return err
+	}
+	data = NormalizeCommentIndentation(buf.Bytes())
+	_, err = f.Write(data)
+	return err
 }
 
 func sanitizeConfigForPersist(cfg *Config) *Config {
@@ -518,13 +525,40 @@ func SaveConfigPreserveCommentsUpdateNestedScalar(configFile string, path []stri
 		return err
 	}
 	defer func() { _ = f.Close() }()
-	enc := yaml.NewEncoder(f)
+	var buf bytes.Buffer
+	enc := yaml.NewEncoder(&buf)
 	enc.SetIndent(2)
 	if err = enc.Encode(&root); err != nil {
 		_ = enc.Close()
 		return err
 	}
-	return enc.Close()
+	if err = enc.Close(); err != nil {
+		return err
+	}
+	data = NormalizeCommentIndentation(buf.Bytes())
+	_, err = f.Write(data)
+	return err
+}
+
+// NormalizeCommentIndentation removes indentation from standalone YAML comment lines to keep them left aligned.
+func NormalizeCommentIndentation(data []byte) []byte {
+	lines := bytes.Split(data, []byte("\n"))
+	changed := false
+	for i, line := range lines {
+		trimmed := bytes.TrimLeft(line, " \t")
+		if len(trimmed) == 0 || trimmed[0] != '#' {
+			continue
+		}
+		if len(trimmed) == len(line) {
+			continue
+		}
+		lines[i] = append([]byte(nil), trimmed...)
+		changed = true
+	}
+	if !changed {
+		return data
+	}
+	return bytes.Join(lines, []byte("\n"))
 }
 
 // getOrCreateMapValue finds the value node for a given key in a mapping node.
@@ -766,6 +800,7 @@ func matchSequenceElement(original []*yaml.Node, used []bool, target *yaml.Node)
 				}
 			}
 		}
+	default:
 	}
 	// Fallback to structural equality to preserve nodes lacking explicit identifiers.
 	for i := range original {

internal/registry/model_registry.go

@@ -4,6 +4,7 @@
 package registry
 
 import (
+	"fmt"
 	"sort"
 	"strings"
 	"sync"
@@ -800,6 +801,9 @@ func (r *ModelRegistry) convertModelToMap(model *ModelInfo, handlerType string)
 		if model.Type != "" {
 			result["type"] = model.Type
 		}
+		if model.Created != 0 {
+			result["created"] = model.Created
+		}
 		return result
 	}
 }
@@ -821,3 +825,47 @@ func (r *ModelRegistry) CleanupExpiredQuotas() {
 		}
 	}
 }
+
+
+// GetFirstAvailableModel returns the first available model for the given handler type.
+// It prioritizes models by their creation timestamp (newest first) and checks if they have
+// available clients that are not suspended or over quota.
+//
+// Parameters:
+//   - handlerType: The API handler type (e.g., "openai", "claude", "gemini")
+//
+// Returns:
+//   - string: The model ID of the first available model, or empty string if none available
+//   - error: An error if no models are available
+func (r *ModelRegistry) GetFirstAvailableModel(handlerType string) (string, error) {
+	r.mutex.RLock()
+	defer r.mutex.RUnlock()
+
+	// Get all available models for this handler type
+	models := r.GetAvailableModels(handlerType)
+	if len(models) == 0 {
+		return "", fmt.Errorf("no models available for handler type: %s", handlerType)
+	}
+
+	// Sort models by creation timestamp (newest first)
+	sort.Slice(models, func(i, j int) bool {
+		// Extract created timestamps from map
+		createdI, okI := models[i]["created"].(int64)
+		createdJ, okJ := models[j]["created"].(int64)
+		if !okI || !okJ {
+			return false
+		}
+		return createdI > createdJ
+	})
+
+	// Find the first model with available clients
+	for _, model := range models {
+		if modelID, ok := model["id"].(string); ok {
+			if count := r.GetModelCount(modelID); count > 0 {
+				return modelID, nil
+			}
+		}
+	}
+
+	return "", fmt.Errorf("no available clients for any model in handler type: %s", handlerType)
+}

internal/runtime/executor/gemini_vertex_executor.go

@@ -22,6 +22,7 @@ import (
 	log "github.com/sirupsen/logrus"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
+	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 )
 
@@ -89,7 +90,7 @@ func (e *GeminiVertexExecutor) Execute(ctx context.Context, auth *cliproxyauth.A
 		return resp, errNewReq
 	}
 	httpReq.Header.Set("Content-Type", "application/json")
-	if token, errTok := vertexAccessToken(ctx, saJSON); errTok == nil && token != "" {
+	if token, errTok := vertexAccessToken(ctx, e.cfg, auth, saJSON); errTok == nil && token != "" {
 		httpReq.Header.Set("Authorization", "Bearer "+token)
 	} else if errTok != nil {
 		log.Errorf("vertex executor: access token error: %v", errTok)
@@ -184,7 +185,7 @@ func (e *GeminiVertexExecutor) ExecuteStream(ctx context.Context, auth *cliproxy
 		return nil, errNewReq
 	}
 	httpReq.Header.Set("Content-Type", "application/json")
-	if token, errTok := vertexAccessToken(ctx, saJSON); errTok == nil && token != "" {
+	if token, errTok := vertexAccessToken(ctx, e.cfg, auth, saJSON); errTok == nil && token != "" {
 		httpReq.Header.Set("Authorization", "Bearer "+token)
 	} else if errTok != nil {
 		log.Errorf("vertex executor: access token error: %v", errTok)
@@ -295,7 +296,7 @@ func (e *GeminiVertexExecutor) CountTokens(ctx context.Context, auth *cliproxyau
 		return cliproxyexecutor.Response{}, errNewReq
 	}
 	httpReq.Header.Set("Content-Type", "application/json")
-	if token, errTok := vertexAccessToken(ctx, saJSON); errTok == nil && token != "" {
+	if token, errTok := vertexAccessToken(ctx, e.cfg, auth, saJSON); errTok == nil && token != "" {
 		httpReq.Header.Set("Authorization", "Bearer "+token)
 	} else if errTok != nil {
 		log.Errorf("vertex executor: access token error: %v", errTok)
@@ -407,7 +408,10 @@ func vertexBaseURL(location string) string {
 	return fmt.Sprintf("https://%s-aiplatform.googleapis.com", loc)
 }
 
-func vertexAccessToken(ctx context.Context, saJSON []byte) (string, error) {
+func vertexAccessToken(ctx context.Context, cfg *config.Config, auth *cliproxyauth.Auth, saJSON []byte) (string, error) {
+	if httpClient := newProxyAwareHTTPClient(ctx, cfg, auth, 0); httpClient != nil {
+		ctx = context.WithValue(ctx, oauth2.HTTPClient, httpClient)
+	}
 	// Use cloud-platform scope for Vertex AI.
 	creds, errCreds := google.CredentialsFromJSON(ctx, saJSON, "https://www.googleapis.com/auth/cloud-platform")
 	if errCreds != nil {

internal/runtime/executor/usage_helpers.go

@@ -129,6 +129,21 @@ func apiKeyFromContext(ctx context.Context) string {
 
 func resolveUsageSource(auth *cliproxyauth.Auth, ctxAPIKey string) string {
 	if auth != nil {
+		provider := strings.TrimSpace(auth.Provider)
+		if strings.EqualFold(provider, "vertex") {
+			if auth.Metadata != nil {
+				if projectID, ok := auth.Metadata["project_id"].(string); ok {
+					if trimmed := strings.TrimSpace(projectID); trimmed != "" {
+						return trimmed
+					}
+				}
+				if project, ok := auth.Metadata["project"].(string); ok {
+					if trimmed := strings.TrimSpace(project); trimmed != "" {
+						return trimmed
+					}
+				}
+			}
+		}
 		if _, value := auth.AccountInfo(); value != "" {
 			return strings.TrimSpace(value)
 		}

internal/translator/gemini/openai/chat-completions/gemini_openai_request.go

@@ -159,7 +159,6 @@ func ConvertOpenAIRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 				}
 			}
 		}
-		fmt.Printf("11111")
 
 		for i := 0; i < len(arr); i++ {
 			m := arr[i]

internal/util/provider.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/registry"
+	log "github.com/sirupsen/logrus"
 )
 
 // GetProviderName determines all AI service providers capable of serving a registered model.
@@ -59,6 +60,30 @@ func GetProviderName(modelName string) []string {
 	return providers
 }
 
+// ResolveAutoModel resolves the "auto" model name to an actual available model.
+// It uses an empty handler type to get any available model from the registry.
+//
+// Parameters:
+//   - modelName: The model name to check (should be "auto")
+//
+// Returns:
+//   - string: The resolved model name, or the original if not "auto" or resolution fails
+func ResolveAutoModel(modelName string) string {
+	if modelName != "auto" {
+		return modelName
+	}
+
+	// Use empty string as handler type to get any available model
+	firstModel, err := registry.GetGlobalRegistry().GetFirstAvailableModel("")
+	if err != nil {
+		log.Warnf("Failed to resolve 'auto' model: %v, falling back to original model name", err)
+		return modelName
+	}
+
+	log.Infof("Resolved 'auto' model to: %s", firstModel)
+	return firstModel
+}
+
 // IsOpenAICompatibilityAlias checks if the given model name is an alias
 // configured for OpenAI compatibility routing.
 //

sdk/api/handlers/handlers.go

@@ -295,11 +295,14 @@ func (h *BaseAPIHandler) ExecuteStreamWithAuthManager(ctx context.Context, handl
 }
 
 func (h *BaseAPIHandler) getRequestDetails(modelName string) (providers []string, normalizedModel string, metadata map[string]any, err *interfaces.ErrorMessage) {
-	providerName, extractedModelName, isDynamic := h.parseDynamicModel(modelName)
+	// Resolve "auto" model to an actual available model first
+	resolvedModelName := util.ResolveAutoModel(modelName)
+	
+	providerName, extractedModelName, isDynamic := h.parseDynamicModel(resolvedModelName)
 
 	// First, normalize the model name to handle suffixes like "-thinking-128"
 	// This needs to happen before determining the provider for non-dynamic models.
-	normalizedModel, metadata = normalizeModelMetadata(modelName)
+	normalizedModel, metadata = normalizeModelMetadata(resolvedModelName)
 
 	if isDynamic {
 		providers = []string{providerName}