feat(auth): prevent filestore writes on unchanged metadata

- Added `metadataEqualIgnoringTimestamps` to compare metadata while ignoring volatile fields.
- Prevented redundant writes caused by changes in timestamp-related fields.
- Improved efficiency in filestore operations by skipping unnecessary updates.

cmd/server/main.go

@@ -61,6 +61,7 @@ func main() {
 	var iflowLogin bool
 	var iflowCookie bool
 	var noBrowser bool
+	var oauthCallbackPort int
 	var antigravityLogin bool
 	var projectID string
 	var vertexImport string
@@ -75,6 +76,7 @@ func main() {
 	flag.BoolVar(&iflowLogin, "iflow-login", false, "Login to iFlow using OAuth")
 	flag.BoolVar(&iflowCookie, "iflow-cookie", false, "Login to iFlow using Cookie")
 	flag.BoolVar(&noBrowser, "no-browser", false, "Don't open browser automatically for OAuth")
+	flag.IntVar(&oauthCallbackPort, "oauth-callback-port", 0, "Override OAuth callback port (defaults to provider-specific port)")
 	flag.BoolVar(&antigravityLogin, "antigravity-login", false, "Login to Antigravity using OAuth")
 	flag.StringVar(&projectID, "project_id", "", "Project ID (Gemini only, not required)")
 	flag.StringVar(&configPath, "config", DefaultConfigPath, "Configure File Path")
@@ -425,7 +427,8 @@ func main() {
 
 	// Create login options to be used in authentication flows.
 	options := &cmd.LoginOptions{
-		NoBrowser: noBrowser,
+		NoBrowser:    noBrowser,
+		CallbackPort: oauthCallbackPort,
 	}
 
 	// Register the shared token store once so all components use the same persistence backend.

config.example.yaml

@@ -77,6 +77,9 @@ routing:
 # When true, enable authentication for the WebSocket API (/v1/ws).
 ws-auth: false
 
+# When > 0, emit blank lines every N seconds for non-streaming responses to prevent idle timeouts.
+nonstream-keepalive-interval: 0
+
 # Streaming behavior (SSE keep-alives + safe bootstrap retries).
 # streaming:
 #   keepalive-seconds: 15   # Default: 0 (disabled). <= 0 disables keep-alives.

internal/auth/gemini/gemini_auth.go

@@ -29,8 +29,9 @@ import (
 )
 
 const (
-	geminiOauthClientID     = "681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com"
+	geminiOauthClientID       = "681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com"
-	geminiOauthClientSecret = "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"
+	geminiOauthClientSecret   = "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"
+	geminiDefaultCallbackPort = 8085
 )
 
 var (
@@ -49,8 +50,9 @@ type GeminiAuth struct {
 
 // WebLoginOptions customizes the interactive OAuth flow.
 type WebLoginOptions struct {
-	NoBrowser bool
+	NoBrowser    bool
-	Prompt    func(string) (string, error)
+	CallbackPort int
+	Prompt       func(string) (string, error)
 }
 
 // NewGeminiAuth creates a new instance of GeminiAuth.
@@ -72,6 +74,12 @@ func NewGeminiAuth() *GeminiAuth {
 //   - *http.Client: An HTTP client configured with authentication
 //   - error: An error if the client configuration fails, nil otherwise
 func (g *GeminiAuth) GetAuthenticatedClient(ctx context.Context, ts *GeminiTokenStorage, cfg *config.Config, opts *WebLoginOptions) (*http.Client, error) {
+	callbackPort := geminiDefaultCallbackPort
+	if opts != nil && opts.CallbackPort > 0 {
+		callbackPort = opts.CallbackPort
+	}
+	callbackURL := fmt.Sprintf("http://localhost:%d/oauth2callback", callbackPort)
+
 	// Configure proxy settings for the HTTP client if a proxy URL is provided.
 	proxyURL, err := url.Parse(cfg.ProxyURL)
 	if err == nil {
@@ -106,7 +114,7 @@ func (g *GeminiAuth) GetAuthenticatedClient(ctx context.Context, ts *GeminiToken
 	conf := &oauth2.Config{
 		ClientID:     geminiOauthClientID,
 		ClientSecret: geminiOauthClientSecret,
-		RedirectURL:  "http://localhost:8085/oauth2callback", // This will be used by the local server.
+		RedirectURL:  callbackURL, // This will be used by the local server.
 		Scopes:       geminiOauthScopes,
 		Endpoint:     google.Endpoint,
 	}
@@ -218,14 +226,20 @@ func (g *GeminiAuth) createTokenStorage(ctx context.Context, config *oauth2.Conf
 //   - *oauth2.Token: The OAuth2 token obtained from the authorization flow
 //   - error: An error if the token acquisition fails, nil otherwise
 func (g *GeminiAuth) getTokenFromWeb(ctx context.Context, config *oauth2.Config, opts *WebLoginOptions) (*oauth2.Token, error) {
+	callbackPort := geminiDefaultCallbackPort
+	if opts != nil && opts.CallbackPort > 0 {
+		callbackPort = opts.CallbackPort
+	}
+	callbackURL := fmt.Sprintf("http://localhost:%d/oauth2callback", callbackPort)
+
 	// Use a channel to pass the authorization code from the HTTP handler to the main function.
 	codeChan := make(chan string, 1)
 	errChan := make(chan error, 1)
 
 	// Create a new HTTP server with its own multiplexer.
 	mux := http.NewServeMux()
-	server := &http.Server{Addr: ":8085", Handler: mux}
+	server := &http.Server{Addr: fmt.Sprintf(":%d", callbackPort), Handler: mux}
-	config.RedirectURL = "http://localhost:8085/oauth2callback"
+	config.RedirectURL = callbackURL
 
 	mux.HandleFunc("/oauth2callback", func(w http.ResponseWriter, r *http.Request) {
 		if err := r.URL.Query().Get("error"); err != "" {
@@ -277,13 +291,13 @@ func (g *GeminiAuth) getTokenFromWeb(ctx context.Context, config *oauth2.Config,
 		// Check if browser is available
 		if !browser.IsAvailable() {
 			log.Warn("No browser available on this system")
-			util.PrintSSHTunnelInstructions(8085)
+			util.PrintSSHTunnelInstructions(callbackPort)
 			fmt.Printf("Please manually open this URL in your browser:\n\n%s\n", authURL)
 		} else {
 			if err := browser.OpenURL(authURL); err != nil {
 				authErr := codex.NewAuthenticationError(codex.ErrBrowserOpenFailed, err)
 				log.Warn(codex.GetUserFriendlyMessage(authErr))
-				util.PrintSSHTunnelInstructions(8085)
+				util.PrintSSHTunnelInstructions(callbackPort)
 				fmt.Printf("Please manually open this URL in your browser:\n\n%s\n", authURL)
 
 				// Log platform info for debugging
@@ -294,7 +308,7 @@ func (g *GeminiAuth) getTokenFromWeb(ctx context.Context, config *oauth2.Config,
 			}
 		}
 	} else {
-		util.PrintSSHTunnelInstructions(8085)
+		util.PrintSSHTunnelInstructions(callbackPort)
 		fmt.Printf("Please open this URL in your browser:\n\n%s\n", authURL)
 	}
 

internal/cmd/anthropic_login.go

@@ -32,9 +32,10 @@ func DoClaudeLogin(cfg *config.Config, options *LoginOptions) {
 	manager := newAuthManager()
 
 	authOpts := &sdkAuth.LoginOptions{
-		NoBrowser: options.NoBrowser,
+		NoBrowser:    options.NoBrowser,
-		Metadata:  map[string]string{},
+		CallbackPort: options.CallbackPort,
-		Prompt:    promptFn,
+		Metadata:     map[string]string{},
+		Prompt:       promptFn,
 	}
 
 	_, savedPath, err := manager.Login(context.Background(), "claude", cfg, authOpts)

internal/cmd/antigravity_login.go

@@ -22,9 +22,10 @@ func DoAntigravityLogin(cfg *config.Config, options *LoginOptions) {
 
 	manager := newAuthManager()
 	authOpts := &sdkAuth.LoginOptions{
-		NoBrowser: options.NoBrowser,
+		NoBrowser:    options.NoBrowser,
-		Metadata:  map[string]string{},
+		CallbackPort: options.CallbackPort,
-		Prompt:    promptFn,
+		Metadata:     map[string]string{},
+		Prompt:       promptFn,
 	}
 
 	record, savedPath, err := manager.Login(context.Background(), "antigravity", cfg, authOpts)

internal/cmd/iflow_login.go

@@ -24,9 +24,10 @@ func DoIFlowLogin(cfg *config.Config, options *LoginOptions) {
 	}
 
 	authOpts := &sdkAuth.LoginOptions{
-		NoBrowser: options.NoBrowser,
+		NoBrowser:    options.NoBrowser,
-		Metadata:  map[string]string{},
+		CallbackPort: options.CallbackPort,
-		Prompt:    promptFn,
+		Metadata:     map[string]string{},
+		Prompt:       promptFn,
 	}
 
 	_, savedPath, err := manager.Login(context.Background(), "iflow", cfg, authOpts)

internal/cmd/login.go

@@ -67,10 +67,11 @@ func DoLogin(cfg *config.Config, projectID string, options *LoginOptions) {
 	}
 
 	loginOpts := &sdkAuth.LoginOptions{
-		NoBrowser: options.NoBrowser,
+		NoBrowser:    options.NoBrowser,
-		ProjectID: trimmedProjectID,
+		ProjectID:    trimmedProjectID,
-		Metadata:  map[string]string{},
+		CallbackPort: options.CallbackPort,
-		Prompt:    callbackPrompt,
+		Metadata:     map[string]string{},
+		Prompt:       callbackPrompt,
 	}
 
 	authenticator := sdkAuth.NewGeminiAuthenticator()
@@ -88,8 +89,9 @@ func DoLogin(cfg *config.Config, projectID string, options *LoginOptions) {
 
 	geminiAuth := gemini.NewGeminiAuth()
 	httpClient, errClient := geminiAuth.GetAuthenticatedClient(ctx, storage, cfg, &gemini.WebLoginOptions{
-		NoBrowser: options.NoBrowser,
+		NoBrowser:    options.NoBrowser,
-		Prompt:    callbackPrompt,
+		CallbackPort: options.CallbackPort,
+		Prompt:       callbackPrompt,
 	})
 	if errClient != nil {
 		log.Errorf("Gemini authentication failed: %v", errClient)

internal/cmd/openai_login.go

@@ -19,6 +19,9 @@ type LoginOptions struct {
 	// NoBrowser indicates whether to skip opening the browser automatically.
 	NoBrowser bool
 
+	// CallbackPort overrides the local OAuth callback port when set (>0).
+	CallbackPort int
+
 	// Prompt allows the caller to provide interactive input when needed.
 	Prompt func(prompt string) (string, error)
 }
@@ -43,9 +46,10 @@ func DoCodexLogin(cfg *config.Config, options *LoginOptions) {
 	manager := newAuthManager()
 
 	authOpts := &sdkAuth.LoginOptions{
-		NoBrowser: options.NoBrowser,
+		NoBrowser:    options.NoBrowser,
-		Metadata:  map[string]string{},
+		CallbackPort: options.CallbackPort,
-		Prompt:    promptFn,
+		Metadata:     map[string]string{},
+		Prompt:       promptFn,
 	}
 
 	_, savedPath, err := manager.Login(context.Background(), "codex", cfg, authOpts)

internal/cmd/qwen_login.go

@@ -36,9 +36,10 @@ func DoQwenLogin(cfg *config.Config, options *LoginOptions) {
 	}
 
 	authOpts := &sdkAuth.LoginOptions{
-		NoBrowser: options.NoBrowser,
+		NoBrowser:    options.NoBrowser,
-		Metadata:  map[string]string{},
+		CallbackPort: options.CallbackPort,
-		Prompt:    promptFn,
+		Metadata:     map[string]string{},
+		Prompt:       promptFn,
 	}
 
 	_, savedPath, err := manager.Login(context.Background(), "qwen", cfg, authOpts)

internal/config/config.go

@@ -242,6 +242,10 @@ type ClaudeKey struct {
 	// APIKey is the authentication key for accessing Claude API services.
 	APIKey string `yaml:"api-key" json:"api-key"`
 
+	// Priority controls selection preference when multiple credentials match.
+	// Higher values are preferred; defaults to 0.
+	Priority int `yaml:"priority,omitempty" json:"priority,omitempty"`
+
 	// Prefix optionally namespaces models for this credential (e.g., "teamA/claude-sonnet-4").
 	Prefix string `yaml:"prefix,omitempty" json:"prefix,omitempty"`
 
@@ -280,6 +284,10 @@ type CodexKey struct {
 	// APIKey is the authentication key for accessing Codex API services.
 	APIKey string `yaml:"api-key" json:"api-key"`
 
+	// Priority controls selection preference when multiple credentials match.
+	// Higher values are preferred; defaults to 0.
+	Priority int `yaml:"priority,omitempty" json:"priority,omitempty"`
+
 	// Prefix optionally namespaces models for this credential (e.g., "teamA/gpt-5-codex").
 	Prefix string `yaml:"prefix,omitempty" json:"prefix,omitempty"`
 
@@ -318,6 +326,10 @@ type GeminiKey struct {
 	// APIKey is the authentication key for accessing Gemini API services.
 	APIKey string `yaml:"api-key" json:"api-key"`
 
+	// Priority controls selection preference when multiple credentials match.
+	// Higher values are preferred; defaults to 0.
+	Priority int `yaml:"priority,omitempty" json:"priority,omitempty"`
+
 	// Prefix optionally namespaces models for this credential (e.g., "teamA/gemini-3-pro-preview").
 	Prefix string `yaml:"prefix,omitempty" json:"prefix,omitempty"`
 
@@ -355,6 +367,10 @@ type OpenAICompatibility struct {
 	// Name is the identifier for this OpenAI compatibility configuration.
 	Name string `yaml:"name" json:"name"`
 
+	// Priority controls selection preference when multiple providers or credentials match.
+	// Higher values are preferred; defaults to 0.
+	Priority int `yaml:"priority,omitempty" json:"priority,omitempty"`
+
 	// Prefix optionally namespaces model aliases for this provider (e.g., "teamA/kimi-k2").
 	Prefix string `yaml:"prefix,omitempty" json:"prefix,omitempty"`
 

internal/config/sdk_config.go

@@ -25,6 +25,10 @@ type SDKConfig struct {
 
 	// Streaming configures server-side streaming behavior (keep-alives and safe bootstrap retries).
 	Streaming StreamingConfig `yaml:"streaming" json:"streaming"`
+
+	// NonStreamKeepAliveInterval controls how often blank lines are emitted for non-streaming responses.
+	// <= 0 disables keep-alives. Value is in seconds.
+	NonStreamKeepAliveInterval int `yaml:"nonstream-keepalive-interval,omitempty" json:"nonstream-keepalive-interval,omitempty"`
 }
 
 // StreamingConfig holds server streaming behavior configuration.

internal/config/vertex_compat.go

@@ -13,6 +13,10 @@ type VertexCompatKey struct {
 	// Maps to the x-goog-api-key header.
 	APIKey string `yaml:"api-key" json:"api-key"`
 
+	// Priority controls selection preference when multiple credentials match.
+	// Higher values are preferred; defaults to 0.
+	Priority int `yaml:"priority,omitempty" json:"priority,omitempty"`
+
 	// Prefix optionally namespaces model aliases for this credential (e.g., "teamA/vertex-pro").
 	Prefix string `yaml:"prefix,omitempty" json:"prefix,omitempty"`
 

internal/runtime/executor/antigravity_executor.go

@@ -25,6 +25,7 @@ import (
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/registry"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
+	sdkAuth "github.com/router-for-me/CLIProxyAPI/v6/sdk/auth"
 	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"
@@ -1104,12 +1105,49 @@ func (e *AntigravityExecutor) refreshToken(ctx context.Context, auth *cliproxyau
 		auth.Metadata["refresh_token"] = tokenResp.RefreshToken
 	}
 	auth.Metadata["expires_in"] = tokenResp.ExpiresIn
-	auth.Metadata["timestamp"] = time.Now().UnixMilli()
+	now := time.Now()
-	auth.Metadata["expired"] = time.Now().Add(time.Duration(tokenResp.ExpiresIn) * time.Second).Format(time.RFC3339)
+	auth.Metadata["timestamp"] = now.UnixMilli()
+	auth.Metadata["expired"] = now.Add(time.Duration(tokenResp.ExpiresIn) * time.Second).Format(time.RFC3339)
 	auth.Metadata["type"] = antigravityAuthType
+	if errProject := e.ensureAntigravityProjectID(ctx, auth, tokenResp.AccessToken); errProject != nil {
+		log.Warnf("antigravity executor: ensure project id failed: %v", errProject)
+	}
 	return auth, nil
 }
 
+func (e *AntigravityExecutor) ensureAntigravityProjectID(ctx context.Context, auth *cliproxyauth.Auth, accessToken string) error {
+	if auth == nil {
+		return nil
+	}
+
+	if auth.Metadata["project_id"] != nil {
+		return nil
+	}
+
+	token := strings.TrimSpace(accessToken)
+	if token == "" {
+		token = metaStringValue(auth.Metadata, "access_token")
+	}
+	if token == "" {
+		return nil
+	}
+
+	httpClient := newProxyAwareHTTPClient(ctx, e.cfg, auth, 0)
+	projectID, errFetch := sdkAuth.FetchAntigravityProjectID(ctx, token, httpClient)
+	if errFetch != nil {
+		return errFetch
+	}
+	if strings.TrimSpace(projectID) == "" {
+		return nil
+	}
+	if auth.Metadata == nil {
+		auth.Metadata = make(map[string]any)
+	}
+	auth.Metadata["project_id"] = strings.TrimSpace(projectID)
+
+	return nil
+}
+
 func (e *AntigravityExecutor) buildRequest(ctx context.Context, auth *cliproxyauth.Auth, token, modelName string, payload []byte, stream bool, alt, baseURL string) (*http.Request, error) {
 	if token == "" {
 		return nil, statusErr{code: http.StatusUnauthorized, msg: "missing access token"}

internal/translator/claude/openai/responses/claude_openai-responses_response.go

@@ -251,6 +251,7 @@ func ConvertClaudeResponseToOpenAIResponses(ctx context.Context, modelName strin
 			itemDone, _ = sjson.Set(itemDone, "item.id", fmt.Sprintf("fc_%s", st.CurrentFCID))
 			itemDone, _ = sjson.Set(itemDone, "item.arguments", args)
 			itemDone, _ = sjson.Set(itemDone, "item.call_id", st.CurrentFCID)
+			itemDone, _ = sjson.Set(itemDone, "item.name", st.FuncNames[idx])
 			out = append(out, emitEvent("response.output_item.done", itemDone))
 			st.InFuncBlock = false
 		} else if st.ReasoningActive {

internal/watcher/diff/config_diff.go

@@ -54,6 +54,9 @@ func BuildConfigChangeDetails(oldCfg, newCfg *config.Config) []string {
 	if oldCfg.ForceModelPrefix != newCfg.ForceModelPrefix {
 		changes = append(changes, fmt.Sprintf("force-model-prefix: %t -> %t", oldCfg.ForceModelPrefix, newCfg.ForceModelPrefix))
 	}
+	if oldCfg.NonStreamKeepAliveInterval != newCfg.NonStreamKeepAliveInterval {
+		changes = append(changes, fmt.Sprintf("nonstream-keepalive-interval: %d -> %d", oldCfg.NonStreamKeepAliveInterval, newCfg.NonStreamKeepAliveInterval))
+	}
 
 	// Quota-exceeded behavior
 	if oldCfg.QuotaExceeded.SwitchProject != newCfg.QuotaExceeded.SwitchProject {

internal/watcher/diff/config_diff_test.go

@@ -231,10 +231,11 @@ func TestBuildConfigChangeDetails_FlagsAndKeys(t *testing.T) {
 		AmpCode:                config.AmpCode{UpstreamAPIKey: "keep", RestrictManagementToLocalhost: false},
 		RemoteManagement:       config.RemoteManagement{DisableControlPanel: false, PanelGitHubRepository: "old/repo", SecretKey: "keep"},
 		SDKConfig: sdkconfig.SDKConfig{
-			RequestLog:       false,
+			RequestLog:                 false,
-			ProxyURL:         "http://old-proxy",
+			ProxyURL:                   "http://old-proxy",
-			APIKeys:          []string{"key-1"},
+			APIKeys:                    []string{"key-1"},
-			ForceModelPrefix: false,
+			ForceModelPrefix:           false,
+			NonStreamKeepAliveInterval: 0,
 		},
 	}
 	newCfg := &config.Config{
@@ -267,10 +268,11 @@ func TestBuildConfigChangeDetails_FlagsAndKeys(t *testing.T) {
 			SecretKey:             "",
 		},
 		SDKConfig: sdkconfig.SDKConfig{
-			RequestLog:       true,
+			RequestLog:                 true,
-			ProxyURL:         "http://new-proxy",
+			ProxyURL:                   "http://new-proxy",
-			APIKeys:          []string{" key-1 ", "key-2"},
+			APIKeys:                    []string{" key-1 ", "key-2"},
-			ForceModelPrefix: true,
+			ForceModelPrefix:           true,
+			NonStreamKeepAliveInterval: 5,
 		},
 	}
 
@@ -285,6 +287,7 @@ func TestBuildConfigChangeDetails_FlagsAndKeys(t *testing.T) {
 	expectContains(t, details, "proxy-url: http://old-proxy -> http://new-proxy")
 	expectContains(t, details, "ws-auth: false -> true")
 	expectContains(t, details, "force-model-prefix: false -> true")
+	expectContains(t, details, "nonstream-keepalive-interval: 0 -> 5")
 	expectContains(t, details, "quota-exceeded.switch-project: false -> true")
 	expectContains(t, details, "quota-exceeded.switch-preview-model: false -> true")
 	expectContains(t, details, "api-keys count: 1 -> 2")

internal/watcher/synthesizer/config.go

@@ -2,6 +2,7 @@ package synthesizer
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/watcher/diff"
@@ -59,6 +60,9 @@ func (s *ConfigSynthesizer) synthesizeGeminiKeys(ctx *SynthesisContext) []*corea
 			"source":  fmt.Sprintf("config:gemini[%s]", token),
 			"api_key": key,
 		}
+		if entry.Priority != 0 {
+			attrs["priority"] = strconv.Itoa(entry.Priority)
+		}
 		if base != "" {
 			attrs["base_url"] = base
 		}
@@ -103,6 +107,9 @@ func (s *ConfigSynthesizer) synthesizeClaudeKeys(ctx *SynthesisContext) []*corea
 			"source":  fmt.Sprintf("config:claude[%s]", token),
 			"api_key": key,
 		}
+		if ck.Priority != 0 {
+			attrs["priority"] = strconv.Itoa(ck.Priority)
+		}
 		if base != "" {
 			attrs["base_url"] = base
 		}
@@ -147,6 +154,9 @@ func (s *ConfigSynthesizer) synthesizeCodexKeys(ctx *SynthesisContext) []*coreau
 			"source":  fmt.Sprintf("config:codex[%s]", token),
 			"api_key": key,
 		}
+		if ck.Priority != 0 {
+			attrs["priority"] = strconv.Itoa(ck.Priority)
+		}
 		if ck.BaseURL != "" {
 			attrs["base_url"] = ck.BaseURL
 		}
@@ -202,6 +212,9 @@ func (s *ConfigSynthesizer) synthesizeOpenAICompat(ctx *SynthesisContext) []*cor
 				"compat_name":  compat.Name,
 				"provider_key": providerName,
 			}
+			if compat.Priority != 0 {
+				attrs["priority"] = strconv.Itoa(compat.Priority)
+			}
 			if key != "" {
 				attrs["api_key"] = key
 			}
@@ -233,6 +246,9 @@ func (s *ConfigSynthesizer) synthesizeOpenAICompat(ctx *SynthesisContext) []*cor
 				"compat_name":  compat.Name,
 				"provider_key": providerName,
 			}
+			if compat.Priority != 0 {
+				attrs["priority"] = strconv.Itoa(compat.Priority)
+			}
 			if hash := diff.ComputeOpenAICompatModelsHash(compat.Models); hash != "" {
 				attrs["models_hash"] = hash
 			}
@@ -275,6 +291,9 @@ func (s *ConfigSynthesizer) synthesizeVertexCompat(ctx *SynthesisContext) []*cor
 			"base_url":     base,
 			"provider_key": providerName,
 		}
+		if compat.Priority != 0 {
+			attrs["priority"] = strconv.Itoa(compat.Priority)
+		}
 		if key != "" {
 			attrs["api_key"] = key
 		}

sdk/api/handlers/claude/code_handlers.go

@@ -146,10 +146,12 @@ func (h *ClaudeCodeAPIHandler) handleNonStreamingResponse(c *gin.Context, rawJSO
 	c.Header("Content-Type", "application/json")
 	alt := h.GetAlt(c)
 	cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
+	stopKeepAlive := h.StartNonStreamingKeepAlive(c, cliCtx)
 
 	modelName := gjson.GetBytes(rawJSON, "model").String()
 
 	resp, errMsg := h.ExecuteWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, alt)
+	stopKeepAlive()
 	if errMsg != nil {
 		h.WriteErrorResponse(c, errMsg)
 		cliCancel(errMsg.Error)
@@ -159,13 +161,18 @@ func (h *ClaudeCodeAPIHandler) handleNonStreamingResponse(c *gin.Context, rawJSO
 	// Decompress gzipped responses - Claude API sometimes returns gzip without Content-Encoding header
 	// This fixes title generation and other non-streaming responses that arrive compressed
 	if len(resp) >= 2 && resp[0] == 0x1f && resp[1] == 0x8b {
-		gzReader, err := gzip.NewReader(bytes.NewReader(resp))
+		gzReader, errGzip := gzip.NewReader(bytes.NewReader(resp))
-		if err != nil {
+		if errGzip != nil {
-			log.Warnf("failed to decompress gzipped Claude response: %v", err)
+			log.Warnf("failed to decompress gzipped Claude response: %v", errGzip)
 		} else {
-			defer gzReader.Close()
+			defer func() {
-			if decompressed, err := io.ReadAll(gzReader); err != nil {
+				if errClose := gzReader.Close(); errClose != nil {
-				log.Warnf("failed to read decompressed Claude response: %v", err)
+					log.Warnf("failed to close Claude gzip reader: %v", errClose)
+				}
+			}()
+			decompressed, errRead := io.ReadAll(gzReader)
+			if errRead != nil {
+				log.Warnf("failed to read decompressed Claude response: %v", errRead)
 			} else {
 				resp = decompressed
 			}

sdk/api/handlers/gemini/gemini_handlers.go

@@ -336,7 +336,9 @@ func (h *GeminiAPIHandler) handleGenerateContent(c *gin.Context, modelName strin
 	c.Header("Content-Type", "application/json")
 	alt := h.GetAlt(c)
 	cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
+	stopKeepAlive := h.StartNonStreamingKeepAlive(c, cliCtx)
 	resp, errMsg := h.ExecuteWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, alt)
+	stopKeepAlive()
 	if errMsg != nil {
 		h.WriteErrorResponse(c, errMsg)
 		cliCancel(errMsg.Error)

sdk/api/handlers/handlers.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"net/http"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/gin-gonic/gin"
@@ -113,6 +114,19 @@ func StreamingKeepAliveInterval(cfg *config.SDKConfig) time.Duration {
 	return time.Duration(seconds) * time.Second
 }
 
+// NonStreamingKeepAliveInterval returns the keep-alive interval for non-streaming responses.
+// Returning 0 disables keep-alives (default when unset).
+func NonStreamingKeepAliveInterval(cfg *config.SDKConfig) time.Duration {
+	seconds := 0
+	if cfg != nil {
+		seconds = cfg.NonStreamKeepAliveInterval
+	}
+	if seconds <= 0 {
+		return 0
+	}
+	return time.Duration(seconds) * time.Second
+}
+
 // StreamingBootstrapRetries returns how many times a streaming request may be retried before any bytes are sent.
 func StreamingBootstrapRetries(cfg *config.SDKConfig) int {
 	retries := defaultStreamingBootstrapRetries
@@ -293,6 +307,53 @@ func (h *BaseAPIHandler) GetContextWithCancel(handler interfaces.APIHandler, c *
 	}
 }
 
+// StartNonStreamingKeepAlive emits blank lines every 5 seconds while waiting for a non-streaming response.
+// It returns a stop function that must be called before writing the final response.
+func (h *BaseAPIHandler) StartNonStreamingKeepAlive(c *gin.Context, ctx context.Context) func() {
+	if h == nil || c == nil {
+		return func() {}
+	}
+	interval := NonStreamingKeepAliveInterval(h.Cfg)
+	if interval <= 0 {
+		return func() {}
+	}
+	flusher, ok := c.Writer.(http.Flusher)
+	if !ok {
+		return func() {}
+	}
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	stopChan := make(chan struct{})
+	var stopOnce sync.Once
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		ticker := time.NewTicker(interval)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-stopChan:
+				return
+			case <-ctx.Done():
+				return
+			case <-ticker.C:
+				_, _ = c.Writer.Write([]byte("\n"))
+				flusher.Flush()
+			}
+		}
+	}()
+
+	return func() {
+		stopOnce.Do(func() {
+			close(stopChan)
+		})
+		wg.Wait()
+	}
+}
+
 // appendAPIResponse preserves any previously captured API response and appends new data.
 func appendAPIResponse(c *gin.Context, data []byte) {
 	if c == nil || len(data) == 0 {

sdk/api/handlers/handlers_stream_bootstrap_test.go

@@ -56,6 +56,14 @@ func (e *failOnceStreamExecutor) CountTokens(context.Context, *coreauth.Auth, co
 	return coreexecutor.Response{}, &coreauth.Error{Code: "not_implemented", Message: "CountTokens not implemented"}
 }
 
+func (e *failOnceStreamExecutor) HttpRequest(ctx context.Context, auth *coreauth.Auth, req *http.Request) (*http.Response, error) {
+	return nil, &coreauth.Error{
+		Code:       "not_implemented",
+		Message:    "HttpRequest not implemented",
+		HTTPStatus: http.StatusNotImplemented,
+	}
+}
+
 func (e *failOnceStreamExecutor) Calls() int {
 	e.mu.Lock()
 	defer e.mu.Unlock()

sdk/api/handlers/openai/openai_handlers.go

@@ -524,7 +524,9 @@ func (h *OpenAIAPIHandler) handleCompletionsNonStreamingResponse(c *gin.Context,
 
 	modelName := gjson.GetBytes(chatCompletionsJSON, "model").String()
 	cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
+	stopKeepAlive := h.StartNonStreamingKeepAlive(c, cliCtx)
 	resp, errMsg := h.ExecuteWithAuthManager(cliCtx, h.HandlerType(), modelName, chatCompletionsJSON, "")
+	stopKeepAlive()
 	if errMsg != nil {
 		h.WriteErrorResponse(c, errMsg)
 		cliCancel(errMsg.Error)

sdk/api/handlers/openai/openai_responses_handlers.go

@@ -103,20 +103,17 @@ func (h *OpenAIResponsesAPIHandler) handleNonStreamingResponse(c *gin.Context, r
 
 	modelName := gjson.GetBytes(rawJSON, "model").String()
 	cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
-	defer func() {
+	stopKeepAlive := h.StartNonStreamingKeepAlive(c, cliCtx)
-		cliCancel()
-	}()
 
 	resp, errMsg := h.ExecuteWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, "")
+	stopKeepAlive()
 	if errMsg != nil {
 		h.WriteErrorResponse(c, errMsg)
+		cliCancel(errMsg.Error)
 		return
 	}
 	_, _ = c.Writer.Write(resp)
-	return
+	cliCancel()
-
-	// no legacy fallback
-
 }
 
 // handleStreamingResponse handles streaming responses for Gemini models.

sdk/auth/antigravity.go

@@ -60,6 +60,11 @@ func (AntigravityAuthenticator) Login(ctx context.Context, cfg *config.Config, o
 		opts = &LoginOptions{}
 	}
 
+	callbackPort := antigravityCallbackPort
+	if opts.CallbackPort > 0 {
+		callbackPort = opts.CallbackPort
+	}
+
 	httpClient := util.SetProxy(&cfg.SDKConfig, &http.Client{})
 
 	state, err := misc.GenerateRandomState()
@@ -67,7 +72,7 @@ func (AntigravityAuthenticator) Login(ctx context.Context, cfg *config.Config, o
 		return nil, fmt.Errorf("antigravity: failed to generate state: %w", err)
 	}
 
-	srv, port, cbChan, errServer := startAntigravityCallbackServer()
+	srv, port, cbChan, errServer := startAntigravityCallbackServer(callbackPort)
 	if errServer != nil {
 		return nil, fmt.Errorf("antigravity: failed to start callback server: %w", errServer)
 	}
@@ -224,13 +229,16 @@ type callbackResult struct {
 	State string
 }
 
-func startAntigravityCallbackServer() (*http.Server, int, <-chan callbackResult, error) {
+func startAntigravityCallbackServer(port int) (*http.Server, int, <-chan callbackResult, error) {
-	addr := fmt.Sprintf(":%d", antigravityCallbackPort)
+	if port <= 0 {
+		port = antigravityCallbackPort
+	}
+	addr := fmt.Sprintf(":%d", port)
 	listener, err := net.Listen("tcp", addr)
 	if err != nil {
 		return nil, 0, nil, err
 	}
-	port := listener.Addr().(*net.TCPAddr).Port
+	port = listener.Addr().(*net.TCPAddr).Port
 	resultCh := make(chan callbackResult, 1)
 
 	mux := http.NewServeMux()
@@ -374,7 +382,7 @@ func fetchAntigravityProjectID(ctx context.Context, accessToken string, httpClie
 	// Call loadCodeAssist to get the project
 	loadReqBody := map[string]any{
 		"metadata": map[string]string{
-			"ideType":    "IDE_UNSPECIFIED",
+			"ideType":    "ANTIGRAVITY",
 			"platform":   "PLATFORM_UNSPECIFIED",
 			"pluginType": "GEMINI",
 		},
@@ -434,8 +442,134 @@ func fetchAntigravityProjectID(ctx context.Context, accessToken string, httpClie
 	}
 
 	if projectID == "" {
-		return "", fmt.Errorf("no cloudaicompanionProject in response")
+		tierID := "legacy-tier"
+		if tiers, okTiers := loadResp["allowedTiers"].([]any); okTiers {
+			for _, rawTier := range tiers {
+				tier, okTier := rawTier.(map[string]any)
+				if !okTier {
+					continue
+				}
+				if isDefault, okDefault := tier["isDefault"].(bool); okDefault && isDefault {
+					if id, okID := tier["id"].(string); okID && strings.TrimSpace(id) != "" {
+						tierID = strings.TrimSpace(id)
+						break
+					}
+				}
+			}
+		}
+
+		projectID, err = antigravityOnboardUser(ctx, accessToken, tierID, httpClient)
+		if err != nil {
+			return "", err
+		}
+		return projectID, nil
 	}
 
 	return projectID, nil
 }
+
+// antigravityOnboardUser attempts to fetch the project ID via onboardUser by polling for completion.
+// It returns an empty string when the operation times out or completes without a project ID.
+func antigravityOnboardUser(ctx context.Context, accessToken, tierID string, httpClient *http.Client) (string, error) {
+	if httpClient == nil {
+		httpClient = http.DefaultClient
+	}
+	fmt.Println("Antigravity: onboarding user...", tierID)
+	requestBody := map[string]any{
+		"tierId": tierID,
+		"metadata": map[string]string{
+			"ideType":    "ANTIGRAVITY",
+			"platform":   "PLATFORM_UNSPECIFIED",
+			"pluginType": "GEMINI",
+		},
+	}
+
+	rawBody, errMarshal := json.Marshal(requestBody)
+	if errMarshal != nil {
+		return "", fmt.Errorf("marshal request body: %w", errMarshal)
+	}
+
+	maxAttempts := 5
+	for attempt := 1; attempt <= maxAttempts; attempt++ {
+		log.Debugf("Polling attempt %d/%d", attempt, maxAttempts)
+
+		reqCtx := ctx
+		var cancel context.CancelFunc
+		if reqCtx == nil {
+			reqCtx = context.Background()
+		}
+		reqCtx, cancel = context.WithTimeout(reqCtx, 30*time.Second)
+
+		endpointURL := fmt.Sprintf("%s/%s:onboardUser", antigravityAPIEndpoint, antigravityAPIVersion)
+		req, errRequest := http.NewRequestWithContext(reqCtx, http.MethodPost, endpointURL, strings.NewReader(string(rawBody)))
+		if errRequest != nil {
+			cancel()
+			return "", fmt.Errorf("create request: %w", errRequest)
+		}
+		req.Header.Set("Authorization", "Bearer "+accessToken)
+		req.Header.Set("Content-Type", "application/json")
+		req.Header.Set("User-Agent", antigravityAPIUserAgent)
+		req.Header.Set("X-Goog-Api-Client", antigravityAPIClient)
+		req.Header.Set("Client-Metadata", antigravityClientMetadata)
+
+		resp, errDo := httpClient.Do(req)
+		if errDo != nil {
+			cancel()
+			return "", fmt.Errorf("execute request: %w", errDo)
+		}
+
+		bodyBytes, errRead := io.ReadAll(resp.Body)
+		if errClose := resp.Body.Close(); errClose != nil {
+			log.Errorf("close body error: %v", errClose)
+		}
+		cancel()
+
+		if errRead != nil {
+			return "", fmt.Errorf("read response: %w", errRead)
+		}
+
+		if resp.StatusCode == http.StatusOK {
+			var data map[string]any
+			if errDecode := json.Unmarshal(bodyBytes, &data); errDecode != nil {
+				return "", fmt.Errorf("decode response: %w", errDecode)
+			}
+
+			if done, okDone := data["done"].(bool); okDone && done {
+				projectID := ""
+				if responseData, okResp := data["response"].(map[string]any); okResp {
+					switch projectValue := responseData["cloudaicompanionProject"].(type) {
+					case map[string]any:
+						if id, okID := projectValue["id"].(string); okID {
+							projectID = strings.TrimSpace(id)
+						}
+					case string:
+						projectID = strings.TrimSpace(projectValue)
+					}
+				}
+
+				if projectID != "" {
+					log.Infof("Successfully fetched project_id: %s", projectID)
+					return projectID, nil
+				}
+
+				return "", fmt.Errorf("no project_id in response")
+			}
+
+			time.Sleep(2 * time.Second)
+			continue
+		}
+
+		responsePreview := strings.TrimSpace(string(bodyBytes))
+		if len(responsePreview) > 500 {
+			responsePreview = responsePreview[:500]
+		}
+
+		responseErr := responsePreview
+		if len(responseErr) > 200 {
+			responseErr = responseErr[:200]
+		}
+		return "", fmt.Errorf("http %d: %s", resp.StatusCode, responseErr)
+	}
+
+	return "", nil
+}

sdk/auth/claude.go

@@ -47,6 +47,11 @@ func (a *ClaudeAuthenticator) Login(ctx context.Context, cfg *config.Config, opt
 		opts = &LoginOptions{}
 	}
 
+	callbackPort := a.CallbackPort
+	if opts.CallbackPort > 0 {
+		callbackPort = opts.CallbackPort
+	}
+
 	pkceCodes, err := claude.GeneratePKCECodes()
 	if err != nil {
 		return nil, fmt.Errorf("claude pkce generation failed: %w", err)
@@ -57,7 +62,7 @@ func (a *ClaudeAuthenticator) Login(ctx context.Context, cfg *config.Config, opt
 		return nil, fmt.Errorf("claude state generation failed: %w", err)
 	}
 
-	oauthServer := claude.NewOAuthServer(a.CallbackPort)
+	oauthServer := claude.NewOAuthServer(callbackPort)
 	if err = oauthServer.Start(); err != nil {
 		if strings.Contains(err.Error(), "already in use") {
 			return nil, claude.NewAuthenticationError(claude.ErrPortInUse, err)
@@ -84,15 +89,15 @@ func (a *ClaudeAuthenticator) Login(ctx context.Context, cfg *config.Config, opt
 		fmt.Println("Opening browser for Claude authentication")
 		if !browser.IsAvailable() {
 			log.Warn("No browser available; please open the URL manually")
-			util.PrintSSHTunnelInstructions(a.CallbackPort)
+			util.PrintSSHTunnelInstructions(callbackPort)
 			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		} else if err = browser.OpenURL(authURL); err != nil {
 			log.Warnf("Failed to open browser automatically: %v", err)
-			util.PrintSSHTunnelInstructions(a.CallbackPort)
+			util.PrintSSHTunnelInstructions(callbackPort)
 			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		}
 	} else {
-		util.PrintSSHTunnelInstructions(a.CallbackPort)
+		util.PrintSSHTunnelInstructions(callbackPort)
 		fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 	}
 

sdk/auth/codex.go

@@ -47,6 +47,11 @@ func (a *CodexAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 		opts = &LoginOptions{}
 	}
 
+	callbackPort := a.CallbackPort
+	if opts.CallbackPort > 0 {
+		callbackPort = opts.CallbackPort
+	}
+
 	pkceCodes, err := codex.GeneratePKCECodes()
 	if err != nil {
 		return nil, fmt.Errorf("codex pkce generation failed: %w", err)
@@ -57,7 +62,7 @@ func (a *CodexAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 		return nil, fmt.Errorf("codex state generation failed: %w", err)
 	}
 
-	oauthServer := codex.NewOAuthServer(a.CallbackPort)
+	oauthServer := codex.NewOAuthServer(callbackPort)
 	if err = oauthServer.Start(); err != nil {
 		if strings.Contains(err.Error(), "already in use") {
 			return nil, codex.NewAuthenticationError(codex.ErrPortInUse, err)
@@ -83,15 +88,15 @@ func (a *CodexAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 		fmt.Println("Opening browser for Codex authentication")
 		if !browser.IsAvailable() {
 			log.Warn("No browser available; please open the URL manually")
-			util.PrintSSHTunnelInstructions(a.CallbackPort)
+			util.PrintSSHTunnelInstructions(callbackPort)
 			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		} else if err = browser.OpenURL(authURL); err != nil {
 			log.Warnf("Failed to open browser automatically: %v", err)
-			util.PrintSSHTunnelInstructions(a.CallbackPort)
+			util.PrintSSHTunnelInstructions(callbackPort)
 			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		}
 	} else {
-		util.PrintSSHTunnelInstructions(a.CallbackPort)
+		util.PrintSSHTunnelInstructions(callbackPort)
 		fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 	}
 

sdk/auth/filestore.go

@@ -5,8 +5,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/fs"
+	"net/http"
 	"os"
 	"path/filepath"
+	"reflect"
 	"strings"
 	"sync"
 	"time"
@@ -77,15 +79,23 @@ func (s *FileTokenStore) Save(ctx context.Context, auth *cliproxyauth.Auth) (str
 			if metadataEqualIgnoringTimestamps(existing, raw) {
 				return path, nil
 			}
-		} else if errRead != nil && !os.IsNotExist(errRead) {
+			file, errOpen := os.OpenFile(path, os.O_WRONLY|os.O_TRUNC, 0o600)
+			if errOpen != nil {
+				return "", fmt.Errorf("auth filestore: open existing failed: %w", errOpen)
+			}
+			if _, errWrite := file.Write(raw); errWrite != nil {
+				_ = file.Close()
+				return "", fmt.Errorf("auth filestore: write existing failed: %w", errWrite)
+			}
+			if errClose := file.Close(); errClose != nil {
+				return "", fmt.Errorf("auth filestore: close existing failed: %w", errClose)
+			}
+			return path, nil
+		} else if !os.IsNotExist(errRead) {
 			return "", fmt.Errorf("auth filestore: read existing failed: %w", errRead)
 		}
-		tmp := path + ".tmp"
+		if errWrite := os.WriteFile(path, raw, 0o600); errWrite != nil {
-		if errWrite := os.WriteFile(tmp, raw, 0o600); errWrite != nil {
+			return "", fmt.Errorf("auth filestore: write file failed: %w", errWrite)
-			return "", fmt.Errorf("auth filestore: write temp failed: %w", errWrite)
-		}
-		if errRename := os.Rename(tmp, path); errRename != nil {
-			return "", fmt.Errorf("auth filestore: rename failed: %w", errRename)
 		}
 	default:
 		return "", fmt.Errorf("auth filestore: nothing to persist for %s", auth.ID)
@@ -178,6 +188,30 @@ func (s *FileTokenStore) readAuthFile(path, baseDir string) (*cliproxyauth.Auth,
 	if provider == "" {
 		provider = "unknown"
 	}
+	if provider == "antigravity" {
+		projectID := ""
+		if pid, ok := metadata["project_id"].(string); ok {
+			projectID = strings.TrimSpace(pid)
+		}
+		if projectID == "" {
+			accessToken := ""
+			if token, ok := metadata["access_token"].(string); ok {
+				accessToken = strings.TrimSpace(token)
+			}
+			if accessToken != "" {
+				fetchedProjectID, errFetch := FetchAntigravityProjectID(context.Background(), accessToken, http.DefaultClient)
+				if errFetch == nil && strings.TrimSpace(fetchedProjectID) != "" {
+					metadata["project_id"] = strings.TrimSpace(fetchedProjectID)
+					if raw, errMarshal := json.Marshal(metadata); errMarshal == nil {
+						if file, errOpen := os.OpenFile(path, os.O_WRONLY|os.O_TRUNC, 0o600); errOpen == nil {
+							_, _ = file.Write(raw)
+							_ = file.Close()
+						}
+					}
+				}
+			}
+		}
+	}
 	info, err := os.Stat(path)
 	if err != nil {
 		return nil, fmt.Errorf("stat file: %w", err)
@@ -266,92 +300,28 @@ func (s *FileTokenStore) baseDirSnapshot() string {
 	return s.baseDir
 }
 
-// DEPRECATED: Use metadataEqualIgnoringTimestamps for comparing auth metadata.
+// metadataEqualIgnoringTimestamps compares two metadata JSON blobs, ignoring volatile fields that
-// This function is kept for backward compatibility but can cause refresh loops.
+// change on every refresh but don't affect authentication logic.
-func jsonEqual(a, b []byte) bool {
-	var objA any
-	var objB any
-	if err := json.Unmarshal(a, &objA); err != nil {
-		return false
-	}
-	if err := json.Unmarshal(b, &objB); err != nil {
-		return false
-	}
-	return deepEqualJSON(objA, objB)
-}
-
-// metadataEqualIgnoringTimestamps compares two metadata JSON blobs,
-// ignoring fields that change on every refresh but don't affect functionality.
-// This prevents unnecessary file writes that would trigger watcher events and
-// create refresh loops.
 func metadataEqualIgnoringTimestamps(a, b []byte) bool {
-	var objA, objB map[string]any
+	var objA map[string]any
-	if err := json.Unmarshal(a, &objA); err != nil {
+	var objB map[string]any
+	if errUnmarshalA := json.Unmarshal(a, &objA); errUnmarshalA != nil {
 		return false
 	}
-	if err := json.Unmarshal(b, &objB); err != nil {
+	if errUnmarshalB := json.Unmarshal(b, &objB); errUnmarshalB != nil {
 		return false
 	}
-
+	stripVolatileMetadataFields(objA)
-	// Fields to ignore: these change on every refresh but don't affect authentication logic.
+	stripVolatileMetadataFields(objB)
-	// - timestamp, expired, expires_in, last_refresh: time-related fields that change on refresh
+	return reflect.DeepEqual(objA, objB)
-	// - access_token: Google OAuth returns a new access_token on each refresh, this is expected
-	//   and shouldn't trigger file writes (the new token will be fetched again when needed)
-	ignoredFields := []string{"timestamp", "expired", "expires_in", "last_refresh", "access_token"}
-	for _, field := range ignoredFields {
-		delete(objA, field)
-		delete(objB, field)
-	}
-
-	return deepEqualJSON(objA, objB)
 }
 
-func deepEqualJSON(a, b any) bool {
+func stripVolatileMetadataFields(metadata map[string]any) {
-	switch valA := a.(type) {
+	if metadata == nil {
-	case map[string]any:
+		return
-		valB, ok := b.(map[string]any)
+	}
-		if !ok || len(valA) != len(valB) {
+	// These fields change on refresh and would otherwise trigger watcher reload loops.
-			return false
+	for _, field := range []string{"timestamp", "expired", "expires_in", "last_refresh", "access_token"} {
-		}
+		delete(metadata, field)
-		for key, subA := range valA {
-			subB, ok1 := valB[key]
-			if !ok1 || !deepEqualJSON(subA, subB) {
-				return false
-			}
-		}
-		return true
-	case []any:
-		sliceB, ok := b.([]any)
-		if !ok || len(valA) != len(sliceB) {
-			return false
-		}
-		for i := range valA {
-			if !deepEqualJSON(valA[i], sliceB[i]) {
-				return false
-			}
-		}
-		return true
-	case float64:
-		valB, ok := b.(float64)
-		if !ok {
-			return false
-		}
-		return valA == valB
-	case string:
-		valB, ok := b.(string)
-		if !ok {
-			return false
-		}
-		return valA == valB
-	case bool:
-		valB, ok := b.(bool)
-		if !ok {
-			return false
-		}
-		return valA == valB
-	case nil:
-		return b == nil
-	default:
-		return false
 	}
 }

sdk/auth/gemini.go

@@ -45,8 +45,9 @@ func (a *GeminiAuthenticator) Login(ctx context.Context, cfg *config.Config, opt
 
 	geminiAuth := gemini.NewGeminiAuth()
 	_, err := geminiAuth.GetAuthenticatedClient(ctx, &ts, cfg, &gemini.WebLoginOptions{
-		NoBrowser: opts.NoBrowser,
+		NoBrowser:    opts.NoBrowser,
-		Prompt:    opts.Prompt,
+		CallbackPort: opts.CallbackPort,
+		Prompt:       opts.Prompt,
 	})
 	if err != nil {
 		return nil, fmt.Errorf("gemini authentication failed: %w", err)

sdk/auth/iflow.go

@@ -42,9 +42,14 @@ func (a *IFlowAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 		opts = &LoginOptions{}
 	}
 
+	callbackPort := iflow.CallbackPort
+	if opts.CallbackPort > 0 {
+		callbackPort = opts.CallbackPort
+	}
+
 	authSvc := iflow.NewIFlowAuth(cfg)
 
-	oauthServer := iflow.NewOAuthServer(iflow.CallbackPort)
+	oauthServer := iflow.NewOAuthServer(callbackPort)
 	if err := oauthServer.Start(); err != nil {
 		if strings.Contains(err.Error(), "already in use") {
 			return nil, fmt.Errorf("iflow authentication server port in use: %w", err)
@@ -64,21 +69,21 @@ func (a *IFlowAuthenticator) Login(ctx context.Context, cfg *config.Config, opts
 		return nil, fmt.Errorf("iflow auth: failed to generate state: %w", err)
 	}
 
-	authURL, redirectURI := authSvc.AuthorizationURL(state, iflow.CallbackPort)
+	authURL, redirectURI := authSvc.AuthorizationURL(state, callbackPort)
 
 	if !opts.NoBrowser {
 		fmt.Println("Opening browser for iFlow authentication")
 		if !browser.IsAvailable() {
 			log.Warn("No browser available; please open the URL manually")
-			util.PrintSSHTunnelInstructions(iflow.CallbackPort)
+			util.PrintSSHTunnelInstructions(callbackPort)
 			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		} else if err = browser.OpenURL(authURL); err != nil {
 			log.Warnf("Failed to open browser automatically: %v", err)
-			util.PrintSSHTunnelInstructions(iflow.CallbackPort)
+			util.PrintSSHTunnelInstructions(callbackPort)
 			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 		}
 	} else {
-		util.PrintSSHTunnelInstructions(iflow.CallbackPort)
+		util.PrintSSHTunnelInstructions(callbackPort)
 		fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
 	}
 

sdk/auth/interfaces.go

@@ -14,10 +14,11 @@ var ErrRefreshNotSupported = errors.New("cliproxy auth: refresh not supported")
 // LoginOptions captures generic knobs shared across authenticators.
 // Provider-specific logic can inspect Metadata for extra parameters.
 type LoginOptions struct {
-	NoBrowser bool
+	NoBrowser    bool
-	ProjectID string
+	ProjectID    string
-	Metadata  map[string]string
+	CallbackPort int
-	Prompt    func(prompt string) (string, error)
+	Metadata     map[string]string
+	Prompt       func(prompt string) (string, error)
 }
 
 // Authenticator manages login and optional refresh flows for a provider.

sdk/cliproxy/auth/conductor.go

@@ -271,7 +271,6 @@ func (m *Manager) Execute(ctx context.Context, providers []string, req cliproxye
 	if len(normalized) == 0 {
 		return cliproxyexecutor.Response{}, &Error{Code: "provider_not_found", Message: "no provider supplied"}
 	}
-	rotated := m.rotateProviders(req.Model, normalized)
 
 	retryTimes, maxWait := m.retrySettings()
 	attempts := retryTimes + 1
@@ -281,14 +280,12 @@ func (m *Manager) Execute(ctx context.Context, providers []string, req cliproxye
 
 	var lastErr error
 	for attempt := 0; attempt < attempts; attempt++ {
-		resp, errExec := m.executeProvidersOnce(ctx, rotated, func(execCtx context.Context, provider string) (cliproxyexecutor.Response, error) {
+		resp, errExec := m.executeMixedOnce(ctx, normalized, req, opts)
-			return m.executeWithProvider(execCtx, provider, req, opts)
-		})
 		if errExec == nil {
 			return resp, nil
 		}
 		lastErr = errExec
-		wait, shouldRetry := m.shouldRetryAfterError(errExec, attempt, attempts, rotated, req.Model, maxWait)
+		wait, shouldRetry := m.shouldRetryAfterError(errExec, attempt, attempts, normalized, req.Model, maxWait)
 		if !shouldRetry {
 			break
 		}
@@ -309,7 +306,6 @@ func (m *Manager) ExecuteCount(ctx context.Context, providers []string, req clip
 	if len(normalized) == 0 {
 		return cliproxyexecutor.Response{}, &Error{Code: "provider_not_found", Message: "no provider supplied"}
 	}
-	rotated := m.rotateProviders(req.Model, normalized)
 
 	retryTimes, maxWait := m.retrySettings()
 	attempts := retryTimes + 1
@@ -319,14 +315,12 @@ func (m *Manager) ExecuteCount(ctx context.Context, providers []string, req clip
 
 	var lastErr error
 	for attempt := 0; attempt < attempts; attempt++ {
-		resp, errExec := m.executeProvidersOnce(ctx, rotated, func(execCtx context.Context, provider string) (cliproxyexecutor.Response, error) {
+		resp, errExec := m.executeCountMixedOnce(ctx, normalized, req, opts)
-			return m.executeCountWithProvider(execCtx, provider, req, opts)
-		})
 		if errExec == nil {
 			return resp, nil
 		}
 		lastErr = errExec
-		wait, shouldRetry := m.shouldRetryAfterError(errExec, attempt, attempts, rotated, req.Model, maxWait)
+		wait, shouldRetry := m.shouldRetryAfterError(errExec, attempt, attempts, normalized, req.Model, maxWait)
 		if !shouldRetry {
 			break
 		}
@@ -347,7 +341,6 @@ func (m *Manager) ExecuteStream(ctx context.Context, providers []string, req cli
 	if len(normalized) == 0 {
 		return nil, &Error{Code: "provider_not_found", Message: "no provider supplied"}
 	}
-	rotated := m.rotateProviders(req.Model, normalized)
 
 	retryTimes, maxWait := m.retrySettings()
 	attempts := retryTimes + 1
@@ -357,14 +350,12 @@ func (m *Manager) ExecuteStream(ctx context.Context, providers []string, req cli
 
 	var lastErr error
 	for attempt := 0; attempt < attempts; attempt++ {
-		chunks, errStream := m.executeStreamProvidersOnce(ctx, rotated, func(execCtx context.Context, provider string) (<-chan cliproxyexecutor.StreamChunk, error) {
+		chunks, errStream := m.executeStreamMixedOnce(ctx, normalized, req, opts)
-			return m.executeStreamWithProvider(execCtx, provider, req, opts)
-		})
 		if errStream == nil {
 			return chunks, nil
 		}
 		lastErr = errStream
-		wait, shouldRetry := m.shouldRetryAfterError(errStream, attempt, attempts, rotated, req.Model, maxWait)
+		wait, shouldRetry := m.shouldRetryAfterError(errStream, attempt, attempts, normalized, req.Model, maxWait)
 		if !shouldRetry {
 			break
 		}
@@ -378,6 +369,167 @@ func (m *Manager) ExecuteStream(ctx context.Context, providers []string, req cli
 	return nil, &Error{Code: "auth_not_found", Message: "no auth available"}
 }
 
+func (m *Manager) executeMixedOnce(ctx context.Context, providers []string, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
+	if len(providers) == 0 {
+		return cliproxyexecutor.Response{}, &Error{Code: "provider_not_found", Message: "no provider supplied"}
+	}
+	routeModel := req.Model
+	tried := make(map[string]struct{})
+	var lastErr error
+	for {
+		auth, executor, provider, errPick := m.pickNextMixed(ctx, providers, routeModel, opts, tried)
+		if errPick != nil {
+			if lastErr != nil {
+				return cliproxyexecutor.Response{}, lastErr
+			}
+			return cliproxyexecutor.Response{}, errPick
+		}
+
+		entry := logEntryWithRequestID(ctx)
+		debugLogAuthSelection(entry, auth, provider, req.Model)
+
+		tried[auth.ID] = struct{}{}
+		execCtx := ctx
+		if rt := m.roundTripperFor(auth); rt != nil {
+			execCtx = context.WithValue(execCtx, roundTripperContextKey{}, rt)
+			execCtx = context.WithValue(execCtx, "cliproxy.roundtripper", rt)
+		}
+		execReq := req
+		execReq.Model, execReq.Metadata = rewriteModelForAuth(routeModel, req.Metadata, auth)
+		execReq.Model, execReq.Metadata = m.applyOAuthModelMapping(auth, execReq.Model, execReq.Metadata)
+		resp, errExec := executor.Execute(execCtx, auth, execReq, opts)
+		result := Result{AuthID: auth.ID, Provider: provider, Model: routeModel, Success: errExec == nil}
+		if errExec != nil {
+			result.Error = &Error{Message: errExec.Error()}
+			var se cliproxyexecutor.StatusError
+			if errors.As(errExec, &se) && se != nil {
+				result.Error.HTTPStatus = se.StatusCode()
+			}
+			if ra := retryAfterFromError(errExec); ra != nil {
+				result.RetryAfter = ra
+			}
+			m.MarkResult(execCtx, result)
+			lastErr = errExec
+			continue
+		}
+		m.MarkResult(execCtx, result)
+		return resp, nil
+	}
+}
+
+func (m *Manager) executeCountMixedOnce(ctx context.Context, providers []string, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
+	if len(providers) == 0 {
+		return cliproxyexecutor.Response{}, &Error{Code: "provider_not_found", Message: "no provider supplied"}
+	}
+	routeModel := req.Model
+	tried := make(map[string]struct{})
+	var lastErr error
+	for {
+		auth, executor, provider, errPick := m.pickNextMixed(ctx, providers, routeModel, opts, tried)
+		if errPick != nil {
+			if lastErr != nil {
+				return cliproxyexecutor.Response{}, lastErr
+			}
+			return cliproxyexecutor.Response{}, errPick
+		}
+
+		entry := logEntryWithRequestID(ctx)
+		debugLogAuthSelection(entry, auth, provider, req.Model)
+
+		tried[auth.ID] = struct{}{}
+		execCtx := ctx
+		if rt := m.roundTripperFor(auth); rt != nil {
+			execCtx = context.WithValue(execCtx, roundTripperContextKey{}, rt)
+			execCtx = context.WithValue(execCtx, "cliproxy.roundtripper", rt)
+		}
+		execReq := req
+		execReq.Model, execReq.Metadata = rewriteModelForAuth(routeModel, req.Metadata, auth)
+		execReq.Model, execReq.Metadata = m.applyOAuthModelMapping(auth, execReq.Model, execReq.Metadata)
+		resp, errExec := executor.CountTokens(execCtx, auth, execReq, opts)
+		result := Result{AuthID: auth.ID, Provider: provider, Model: routeModel, Success: errExec == nil}
+		if errExec != nil {
+			result.Error = &Error{Message: errExec.Error()}
+			var se cliproxyexecutor.StatusError
+			if errors.As(errExec, &se) && se != nil {
+				result.Error.HTTPStatus = se.StatusCode()
+			}
+			if ra := retryAfterFromError(errExec); ra != nil {
+				result.RetryAfter = ra
+			}
+			m.MarkResult(execCtx, result)
+			lastErr = errExec
+			continue
+		}
+		m.MarkResult(execCtx, result)
+		return resp, nil
+	}
+}
+
+func (m *Manager) executeStreamMixedOnce(ctx context.Context, providers []string, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (<-chan cliproxyexecutor.StreamChunk, error) {
+	if len(providers) == 0 {
+		return nil, &Error{Code: "provider_not_found", Message: "no provider supplied"}
+	}
+	routeModel := req.Model
+	tried := make(map[string]struct{})
+	var lastErr error
+	for {
+		auth, executor, provider, errPick := m.pickNextMixed(ctx, providers, routeModel, opts, tried)
+		if errPick != nil {
+			if lastErr != nil {
+				return nil, lastErr
+			}
+			return nil, errPick
+		}
+
+		entry := logEntryWithRequestID(ctx)
+		debugLogAuthSelection(entry, auth, provider, req.Model)
+
+		tried[auth.ID] = struct{}{}
+		execCtx := ctx
+		if rt := m.roundTripperFor(auth); rt != nil {
+			execCtx = context.WithValue(execCtx, roundTripperContextKey{}, rt)
+			execCtx = context.WithValue(execCtx, "cliproxy.roundtripper", rt)
+		}
+		execReq := req
+		execReq.Model, execReq.Metadata = rewriteModelForAuth(routeModel, req.Metadata, auth)
+		execReq.Model, execReq.Metadata = m.applyOAuthModelMapping(auth, execReq.Model, execReq.Metadata)
+		chunks, errStream := executor.ExecuteStream(execCtx, auth, execReq, opts)
+		if errStream != nil {
+			rerr := &Error{Message: errStream.Error()}
+			var se cliproxyexecutor.StatusError
+			if errors.As(errStream, &se) && se != nil {
+				rerr.HTTPStatus = se.StatusCode()
+			}
+			result := Result{AuthID: auth.ID, Provider: provider, Model: routeModel, Success: false, Error: rerr}
+			result.RetryAfter = retryAfterFromError(errStream)
+			m.MarkResult(execCtx, result)
+			lastErr = errStream
+			continue
+		}
+		out := make(chan cliproxyexecutor.StreamChunk)
+		go func(streamCtx context.Context, streamAuth *Auth, streamProvider string, streamChunks <-chan cliproxyexecutor.StreamChunk) {
+			defer close(out)
+			var failed bool
+			for chunk := range streamChunks {
+				if chunk.Err != nil && !failed {
+					failed = true
+					rerr := &Error{Message: chunk.Err.Error()}
+					var se cliproxyexecutor.StatusError
+					if errors.As(chunk.Err, &se) && se != nil {
+						rerr.HTTPStatus = se.StatusCode()
+					}
+					m.MarkResult(streamCtx, Result{AuthID: streamAuth.ID, Provider: streamProvider, Model: routeModel, Success: false, Error: rerr})
+				}
+				out <- chunk
+			}
+			if !failed {
+				m.MarkResult(streamCtx, Result{AuthID: streamAuth.ID, Provider: streamProvider, Model: routeModel, Success: true})
+			}
+		}(execCtx, auth.Clone(), provider, chunks)
+		return out, nil
+	}
+}
+
 func (m *Manager) executeWithProvider(ctx context.Context, provider string, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
 	if provider == "" {
 		return cliproxyexecutor.Response{}, &Error{Code: "provider_not_found", Message: "provider identifier is empty"}
@@ -1191,6 +1343,77 @@ func (m *Manager) pickNext(ctx context.Context, provider, model string, opts cli
 	return authCopy, executor, nil
 }
 
+func (m *Manager) pickNextMixed(ctx context.Context, providers []string, model string, opts cliproxyexecutor.Options, tried map[string]struct{}) (*Auth, ProviderExecutor, string, error) {
+	providerSet := make(map[string]struct{}, len(providers))
+	for _, provider := range providers {
+		p := strings.TrimSpace(strings.ToLower(provider))
+		if p == "" {
+			continue
+		}
+		providerSet[p] = struct{}{}
+	}
+	if len(providerSet) == 0 {
+		return nil, nil, "", &Error{Code: "provider_not_found", Message: "no provider supplied"}
+	}
+
+	m.mu.RLock()
+	candidates := make([]*Auth, 0, len(m.auths))
+	modelKey := strings.TrimSpace(model)
+	registryRef := registry.GetGlobalRegistry()
+	for _, candidate := range m.auths {
+		if candidate == nil || candidate.Disabled {
+			continue
+		}
+		providerKey := strings.TrimSpace(strings.ToLower(candidate.Provider))
+		if providerKey == "" {
+			continue
+		}
+		if _, ok := providerSet[providerKey]; !ok {
+			continue
+		}
+		if _, used := tried[candidate.ID]; used {
+			continue
+		}
+		if _, ok := m.executors[providerKey]; !ok {
+			continue
+		}
+		if modelKey != "" && registryRef != nil && !registryRef.ClientSupportsModel(candidate.ID, modelKey) {
+			continue
+		}
+		candidates = append(candidates, candidate)
+	}
+	if len(candidates) == 0 {
+		m.mu.RUnlock()
+		return nil, nil, "", &Error{Code: "auth_not_found", Message: "no auth available"}
+	}
+	selected, errPick := m.selector.Pick(ctx, "mixed", model, opts, candidates)
+	if errPick != nil {
+		m.mu.RUnlock()
+		return nil, nil, "", errPick
+	}
+	if selected == nil {
+		m.mu.RUnlock()
+		return nil, nil, "", &Error{Code: "auth_not_found", Message: "selector returned no auth"}
+	}
+	providerKey := strings.TrimSpace(strings.ToLower(selected.Provider))
+	executor, okExecutor := m.executors[providerKey]
+	if !okExecutor {
+		m.mu.RUnlock()
+		return nil, nil, "", &Error{Code: "executor_not_found", Message: "executor not registered"}
+	}
+	authCopy := selected.Clone()
+	m.mu.RUnlock()
+	if !selected.indexAssigned {
+		m.mu.Lock()
+		if current := m.auths[authCopy.ID]; current != nil && !current.indexAssigned {
+			current.EnsureIndex()
+			authCopy = current.Clone()
+		}
+		m.mu.Unlock()
+	}
+	return authCopy, executor, providerKey, nil
+}
+
 func (m *Manager) persist(ctx context.Context, auth *Auth) error {
 	if m.store == nil || auth == nil {
 		return nil

sdk/cliproxy/auth/selector.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"sort"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -103,13 +104,29 @@ func (e *modelCooldownError) Headers() http.Header {
 	return headers
 }
 
-func collectAvailable(auths []*Auth, model string, now time.Time) (available []*Auth, cooldownCount int, earliest time.Time) {
+func authPriority(auth *Auth) int {
-	available = make([]*Auth, 0, len(auths))
+	if auth == nil || auth.Attributes == nil {
+		return 0
+	}
+	raw := strings.TrimSpace(auth.Attributes["priority"])
+	if raw == "" {
+		return 0
+	}
+	parsed, err := strconv.Atoi(raw)
+	if err != nil {
+		return 0
+	}
+	return parsed
+}
+
+func collectAvailableByPriority(auths []*Auth, model string, now time.Time) (available map[int][]*Auth, cooldownCount int, earliest time.Time) {
+	available = make(map[int][]*Auth)
 	for i := 0; i < len(auths); i++ {
 		candidate := auths[i]
 		blocked, reason, next := isAuthBlockedForModel(candidate, model, now)
 		if !blocked {
-			available = append(available, candidate)
+			priority := authPriority(candidate)
+			available[priority] = append(available[priority], candidate)
 			continue
 		}
 		if reason == blockReasonCooldown {
@@ -119,9 +136,6 @@ func collectAvailable(auths []*Auth, model string, now time.Time) (available []*
 			}
 		}
 	}
-	if len(available) > 1 {
-		sort.Slice(available, func(i, j int) bool { return available[i].ID < available[j].ID })
-	}
 	return available, cooldownCount, earliest
 }
 
@@ -130,18 +144,35 @@ func getAvailableAuths(auths []*Auth, provider, model string, now time.Time) ([]
 		return nil, &Error{Code: "auth_not_found", Message: "no auth candidates"}
 	}
 
-	available, cooldownCount, earliest := collectAvailable(auths, model, now)
+	availableByPriority, cooldownCount, earliest := collectAvailableByPriority(auths, model, now)
-	if len(available) == 0 {
+	if len(availableByPriority) == 0 {
 		if cooldownCount == len(auths) && !earliest.IsZero() {
+			providerForError := provider
+			if providerForError == "mixed" {
+				providerForError = ""
+			}
 			resetIn := earliest.Sub(now)
 			if resetIn < 0 {
 				resetIn = 0
 			}
-			return nil, newModelCooldownError(model, provider, resetIn)
+			return nil, newModelCooldownError(model, providerForError, resetIn)
 		}
 		return nil, &Error{Code: "auth_unavailable", Message: "no auth available"}
 	}
 
+	bestPriority := 0
+	found := false
+	for priority := range availableByPriority {
+		if !found || priority > bestPriority {
+			bestPriority = priority
+			found = true
+		}
+	}
+
+	available := availableByPriority[bestPriority]
+	if len(available) > 1 {
+		sort.Slice(available, func(i, j int) bool { return available[i].ID < available[j].ID })
+	}
 	return available, nil
 }
 

sdk/cliproxy/auth/selector_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"sync"
 	"testing"
+	"time"
 
 	cliproxyexecutor "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/executor"
 )
@@ -56,6 +57,69 @@ func TestRoundRobinSelectorPick_CyclesDeterministic(t *testing.T) {
 	}
 }
 
+func TestRoundRobinSelectorPick_PriorityBuckets(t *testing.T) {
+	t.Parallel()
+
+	selector := &RoundRobinSelector{}
+	auths := []*Auth{
+		{ID: "c", Attributes: map[string]string{"priority": "0"}},
+		{ID: "a", Attributes: map[string]string{"priority": "10"}},
+		{ID: "b", Attributes: map[string]string{"priority": "10"}},
+	}
+
+	want := []string{"a", "b", "a", "b"}
+	for i, id := range want {
+		got, err := selector.Pick(context.Background(), "mixed", "", cliproxyexecutor.Options{}, auths)
+		if err != nil {
+			t.Fatalf("Pick() #%d error = %v", i, err)
+		}
+		if got == nil {
+			t.Fatalf("Pick() #%d auth = nil", i)
+		}
+		if got.ID != id {
+			t.Fatalf("Pick() #%d auth.ID = %q, want %q", i, got.ID, id)
+		}
+		if got.ID == "c" {
+			t.Fatalf("Pick() #%d unexpectedly selected lower priority auth", i)
+		}
+	}
+}
+
+func TestFillFirstSelectorPick_PriorityFallbackCooldown(t *testing.T) {
+	t.Parallel()
+
+	selector := &FillFirstSelector{}
+	now := time.Now()
+	model := "test-model"
+
+	high := &Auth{
+		ID:         "high",
+		Attributes: map[string]string{"priority": "10"},
+		ModelStates: map[string]*ModelState{
+			model: {
+				Status:         StatusActive,
+				Unavailable:    true,
+				NextRetryAfter: now.Add(30 * time.Minute),
+				Quota: QuotaState{
+					Exceeded: true,
+				},
+			},
+		},
+	}
+	low := &Auth{ID: "low", Attributes: map[string]string{"priority": "0"}}
+
+	got, err := selector.Pick(context.Background(), "mixed", model, cliproxyexecutor.Options{}, []*Auth{high, low})
+	if err != nil {
+		t.Fatalf("Pick() error = %v", err)
+	}
+	if got == nil {
+		t.Fatalf("Pick() auth = nil")
+	}
+	if got.ID != "low" {
+		t.Fatalf("Pick() auth.ID = %q, want %q", got.ID, "low")
+	}
+}
+
 func TestRoundRobinSelectorPick_Concurrent(t *testing.T) {
 	selector := &RoundRobinSelector{}
 	auths := []*Auth{