Merge pull request #488 from router-for-me/gemini

Unify the Gemini executor style

internal/runtime/executor/aistudio_executor.go

@@ -1,3 +1,6 @@
+// Package executor provides runtime execution capabilities for various AI service providers.
+// This file implements the AI Studio executor that routes requests through a websocket-backed
+// transport for the AI Studio provider.
 package executor
 
 import (
@@ -26,19 +29,28 @@ type AIStudioExecutor struct {
 	cfg      *config.Config
 }
 
-// NewAIStudioExecutor constructs a websocket executor for the provider name.
+// NewAIStudioExecutor creates a new AI Studio executor instance.
+//
+// Parameters:
+//   - cfg: The application configuration
+//   - provider: The provider name
+//   - relay: The websocket relay manager
+//
+// Returns:
+//   - *AIStudioExecutor: A new AI Studio executor instance
 func NewAIStudioExecutor(cfg *config.Config, provider string, relay *wsrelay.Manager) *AIStudioExecutor {
 	return &AIStudioExecutor{provider: strings.ToLower(provider), relay: relay, cfg: cfg}
 }
 
-// Identifier returns the logical provider key for routing.
+// Identifier returns the executor identifier.
 func (e *AIStudioExecutor) Identifier() string { return "aistudio" }
 
-// PrepareRequest is a no-op because websocket transport already injects headers.
+// PrepareRequest prepares the HTTP request for execution (no-op for AI Studio).
 func (e *AIStudioExecutor) PrepareRequest(_ *http.Request, _ *cliproxyauth.Auth) error {
 	return nil
 }
 
+// Execute performs a non-streaming request to the AI Studio API.
 func (e *AIStudioExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
@@ -92,6 +104,7 @@ func (e *AIStudioExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth,
 	return resp, nil
 }
 
+// ExecuteStream performs a streaming request to the AI Studio API.
 func (e *AIStudioExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (stream <-chan cliproxyexecutor.StreamChunk, err error) {
 	reporter := newUsageReporter(ctx, e.Identifier(), req.Model, auth)
 	defer reporter.trackFailure(ctx, &err)
@@ -239,6 +252,7 @@ func (e *AIStudioExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth
 	return stream, nil
 }
 
+// CountTokens counts tokens for the given request using the AI Studio API.
 func (e *AIStudioExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
 	_, body, err := e.translateRequest(req, opts, false)
 	if err != nil {
@@ -293,8 +307,8 @@ func (e *AIStudioExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.A
 	return cliproxyexecutor.Response{Payload: []byte(translated)}, nil
 }
 
-func (e *AIStudioExecutor) Refresh(ctx context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
+// Refresh refreshes the authentication credentials (no-op for AI Studio).
-	_ = ctx
+func (e *AIStudioExecutor) Refresh(_ context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
 	return auth, nil
 }
 

internal/runtime/executor/antigravity_executor.go

@@ -1,3 +1,6 @@
+// Package executor provides runtime execution capabilities for various AI service providers.
+// This file implements the Antigravity executor that proxies requests to the antigravity
+// upstream using OAuth credentials.
 package executor
 
 import (
@@ -38,7 +41,6 @@ const (
 	defaultAntigravityAgent = "antigravity/1.11.5 windows/amd64"
 	antigravityAuthType     = "antigravity"
 	refreshSkew             = 3000 * time.Second
-	streamScannerBuffer     int = 52_428_800 // 50MB
 )
 
 var randSource = rand.New(rand.NewSource(time.Now().UnixNano()))
@@ -48,18 +50,24 @@ type AntigravityExecutor struct {
 	cfg *config.Config
 }
 
-// NewAntigravityExecutor constructs a new executor instance.
+// NewAntigravityExecutor creates a new Antigravity executor instance.
+//
+// Parameters:
+//   - cfg: The application configuration
+//
+// Returns:
+//   - *AntigravityExecutor: A new Antigravity executor instance
 func NewAntigravityExecutor(cfg *config.Config) *AntigravityExecutor {
 	return &AntigravityExecutor{cfg: cfg}
 }
 
-// Identifier implements ProviderExecutor.
+// Identifier returns the executor identifier.
 func (e *AntigravityExecutor) Identifier() string { return antigravityAuthType }
 
-// PrepareRequest implements ProviderExecutor.
+// PrepareRequest prepares the HTTP request for execution (no-op for Antigravity).
 func (e *AntigravityExecutor) PrepareRequest(_ *http.Request, _ *cliproxyauth.Auth) error { return nil }
 
-// Execute handles non-streaming requests via the antigravity generate endpoint.
+// Execute performs a non-streaming request to the Antigravity API.
 func (e *AntigravityExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
 	token, updatedAuth, errToken := e.ensureAccessToken(ctx, auth)
 	if errToken != nil {
@@ -152,7 +160,7 @@ func (e *AntigravityExecutor) Execute(ctx context.Context, auth *cliproxyauth.Au
 	return resp, err
 }
 
-// ExecuteStream handles streaming requests via the antigravity upstream.
+// ExecuteStream performs a streaming request to the Antigravity API.
 func (e *AntigravityExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (stream <-chan cliproxyexecutor.StreamChunk, err error) {
 	ctx = context.WithValue(ctx, "alt", "")
 
@@ -292,7 +300,7 @@ func (e *AntigravityExecutor) ExecuteStream(ctx context.Context, auth *cliproxya
 	return nil, err
 }
 
-// Refresh refreshes the OAuth token using the refresh token.
+// Refresh refreshes the authentication credentials using the refresh token.
 func (e *AntigravityExecutor) Refresh(ctx context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
 	if auth == nil {
 		return auth, nil
@@ -304,7 +312,7 @@ func (e *AntigravityExecutor) Refresh(ctx context.Context, auth *cliproxyauth.Au
 	return updated, nil
 }
 
-// CountTokens is not supported for the antigravity provider.
+// CountTokens counts tokens for the given request (not supported for Antigravity).
 func (e *AntigravityExecutor) CountTokens(context.Context, *cliproxyauth.Auth, cliproxyexecutor.Request, cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
 	return cliproxyexecutor.Response{}, statusErr{code: http.StatusNotImplemented, msg: "count tokens not supported"}
 }

internal/runtime/executor/gemini_cli_executor.go

@@ -1,3 +1,6 @@
+// Package executor provides runtime execution capabilities for various AI service providers.
+// This file implements the Gemini CLI executor that talks to Cloud Code Assist endpoints
+// using OAuth credentials from auth metadata.
 package executor
 
 import (
@@ -29,11 +32,11 @@ import (
 const (
 	codeAssistEndpoint      = "https://cloudcode-pa.googleapis.com"
 	codeAssistVersion       = "v1internal"
-	geminiOauthClientID     = "681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com"
+	geminiOAuthClientID     = "681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com"
-	geminiOauthClientSecret = "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"
+	geminiOAuthClientSecret = "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"
 )
 
-var geminiOauthScopes = []string{
+var geminiOAuthScopes = []string{
 	"https://www.googleapis.com/auth/cloud-platform",
 	"https://www.googleapis.com/auth/userinfo.email",
 	"https://www.googleapis.com/auth/userinfo.profile",
@@ -44,14 +47,24 @@ type GeminiCLIExecutor struct {
 	cfg *config.Config
 }
 
+// NewGeminiCLIExecutor creates a new Gemini CLI executor instance.
+//
+// Parameters:
+//   - cfg: The application configuration
+//
+// Returns:
+//   - *GeminiCLIExecutor: A new Gemini CLI executor instance
 func NewGeminiCLIExecutor(cfg *config.Config) *GeminiCLIExecutor {
 	return &GeminiCLIExecutor{cfg: cfg}
 }
 
+// Identifier returns the executor identifier.
 func (e *GeminiCLIExecutor) Identifier() string { return "gemini-cli" }
 
+// PrepareRequest prepares the HTTP request for execution (no-op for Gemini CLI).
 func (e *GeminiCLIExecutor) PrepareRequest(_ *http.Request, _ *cliproxyauth.Auth) error { return nil }
 
+// Execute performs a non-streaming request to the Gemini CLI API.
 func (e *GeminiCLIExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
 	tokenSource, baseTokenData, err := prepareGeminiCLITokenSource(ctx, e.cfg, auth)
 	if err != nil {
@@ -189,6 +202,7 @@ func (e *GeminiCLIExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth
 	return resp, err
 }
 
+// ExecuteStream performs a streaming request to the Gemini CLI API.
 func (e *GeminiCLIExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (stream <-chan cliproxyexecutor.StreamChunk, err error) {
 	tokenSource, baseTokenData, err := prepareGeminiCLITokenSource(ctx, e.cfg, auth)
 	if err != nil {
@@ -309,7 +323,7 @@ func (e *GeminiCLIExecutor) ExecuteStream(ctx context.Context, auth *cliproxyaut
 			}()
 			if opts.Alt == "" {
 				scanner := bufio.NewScanner(resp.Body)
-				scanner.Buffer(nil, 52_428_800) // 50MB
+				scanner.Buffer(nil, streamScannerBuffer)
 				var param any
 				for scanner.Scan() {
 					line := scanner.Bytes()
@@ -371,6 +385,7 @@ func (e *GeminiCLIExecutor) ExecuteStream(ctx context.Context, auth *cliproxyaut
 	return nil, err
 }
 
+// CountTokens counts tokens for the given request using the Gemini CLI API.
 func (e *GeminiCLIExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
 	tokenSource, baseTokenData, err := prepareGeminiCLITokenSource(ctx, e.cfg, auth)
 	if err != nil {
@@ -471,9 +486,8 @@ func (e *GeminiCLIExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.
 	return cliproxyexecutor.Response{}, newGeminiStatusErr(lastStatus, lastBody)
 }
 
-func (e *GeminiCLIExecutor) Refresh(ctx context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
+// Refresh refreshes the authentication credentials (no-op for Gemini CLI).
-	log.Debugf("gemini cli executor: refresh called")
+func (e *GeminiCLIExecutor) Refresh(_ context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
-	_ = ctx
 	return auth, nil
 }
 
@@ -515,9 +529,9 @@ func prepareGeminiCLITokenSource(ctx context.Context, cfg *config.Config, auth *
 	}
 
 	conf := &oauth2.Config{
-		ClientID:     geminiOauthClientID,
+		ClientID:     geminiOAuthClientID,
-		ClientSecret: geminiOauthClientSecret,
+		ClientSecret: geminiOAuthClientSecret,
-		Scopes:       geminiOauthScopes,
+		Scopes:       geminiOAuthScopes,
 		Endpoint:     google.Endpoint,
 	}
 

internal/runtime/executor/gemini_executor.go

@@ -11,7 +11,6 @@ import (
 	"io"
 	"net/http"
 	"strings"
-	"time"
 
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
@@ -21,8 +20,6 @@ import (
 	log "github.com/sirupsen/logrus"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
-	"golang.org/x/oauth2"
-	"golang.org/x/oauth2/google"
 )
 
 const (
@@ -31,6 +28,9 @@ const (
 
 	// glAPIVersion is the API version used for Gemini requests.
 	glAPIVersion = "v1beta"
+
+	// streamScannerBuffer is the buffer size for SSE stream scanning.
+	streamScannerBuffer = 52_428_800
 )
 
 // GeminiExecutor is a stateless executor for the official Gemini API using API keys.
@@ -48,9 +48,11 @@ type GeminiExecutor struct {
 //
 // Returns:
 //   - *GeminiExecutor: A new Gemini executor instance
-func NewGeminiExecutor(cfg *config.Config) *GeminiExecutor { return &GeminiExecutor{cfg: cfg} }
+func NewGeminiExecutor(cfg *config.Config) *GeminiExecutor {
+	return &GeminiExecutor{cfg: cfg}
+}
 
-// Identifier returns the executor identifier for Gemini.
+// Identifier returns the executor identifier.
 func (e *GeminiExecutor) Identifier() string { return "gemini" }
 
 // PrepareRequest prepares the HTTP request for execution (no-op for Gemini).
@@ -164,6 +166,7 @@ func (e *GeminiExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	return resp, nil
 }
 
+// ExecuteStream performs a streaming request to the Gemini API.
 func (e *GeminiExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (stream <-chan cliproxyexecutor.StreamChunk, err error) {
 	apiKey, bearer := geminiCreds(auth)
 
@@ -249,7 +252,7 @@ func (e *GeminiExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 			}
 		}()
 		scanner := bufio.NewScanner(httpResp.Body)
-		scanner.Buffer(nil, 52_428_800) // 50MB
+		scanner.Buffer(nil, streamScannerBuffer)
 		var param any
 		for scanner.Scan() {
 			line := scanner.Bytes()
@@ -280,6 +283,7 @@ func (e *GeminiExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 	return stream, nil
 }
 
+// CountTokens counts tokens for the given request using the Gemini API.
 func (e *GeminiExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
 	apiKey, bearer := geminiCreds(auth)
 
@@ -353,106 +357,8 @@ func (e *GeminiExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Aut
 	return cliproxyexecutor.Response{Payload: []byte(translated)}, nil
 }
 
-func (e *GeminiExecutor) Refresh(ctx context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
+// Refresh refreshes the authentication credentials (no-op for Gemini API key).
-	log.Debugf("gemini executor: refresh called")
+func (e *GeminiExecutor) Refresh(_ context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
-	// OAuth bearer token refresh for official Gemini API.
-	if auth == nil {
-		return nil, fmt.Errorf("gemini executor: auth is nil")
-	}
-	if auth.Metadata == nil {
-		return auth, nil
-	}
-	// Token data is typically nested under "token" map in Gemini files.
-	tokenMap, _ := auth.Metadata["token"].(map[string]any)
-	var refreshToken, accessToken, clientID, clientSecret, tokenURI, expiryStr string
-	if tokenMap != nil {
-		if v, ok := tokenMap["refresh_token"].(string); ok {
-			refreshToken = v
-		}
-		if v, ok := tokenMap["access_token"].(string); ok {
-			accessToken = v
-		}
-		if v, ok := tokenMap["client_id"].(string); ok {
-			clientID = v
-		}
-		if v, ok := tokenMap["client_secret"].(string); ok {
-			clientSecret = v
-		}
-		if v, ok := tokenMap["token_uri"].(string); ok {
-			tokenURI = v
-		}
-		if v, ok := tokenMap["expiry"].(string); ok {
-			expiryStr = v
-		}
-	} else {
-		// Fallback to top-level keys if present
-		if v, ok := auth.Metadata["refresh_token"].(string); ok {
-			refreshToken = v
-		}
-		if v, ok := auth.Metadata["access_token"].(string); ok {
-			accessToken = v
-		}
-		if v, ok := auth.Metadata["client_id"].(string); ok {
-			clientID = v
-		}
-		if v, ok := auth.Metadata["client_secret"].(string); ok {
-			clientSecret = v
-		}
-		if v, ok := auth.Metadata["token_uri"].(string); ok {
-			tokenURI = v
-		}
-		if v, ok := auth.Metadata["expiry"].(string); ok {
-			expiryStr = v
-		}
-	}
-	if refreshToken == "" {
-		// Nothing to do for API key or cookie based entries
-		return auth, nil
-	}
-
-	// Prepare oauth2 config; default to Google endpoints
-	endpoint := google.Endpoint
-	if tokenURI != "" {
-		endpoint.TokenURL = tokenURI
-	}
-	conf := &oauth2.Config{ClientID: clientID, ClientSecret: clientSecret, Endpoint: endpoint}
-
-	// Ensure proxy-aware HTTP client for token refresh
-	httpClient := util.SetProxy(&e.cfg.SDKConfig, &http.Client{})
-	ctx = context.WithValue(ctx, oauth2.HTTPClient, httpClient)
-
-	// Build base token
-	tok := &oauth2.Token{AccessToken: accessToken, RefreshToken: refreshToken}
-	if t, err := time.Parse(time.RFC3339, expiryStr); err == nil {
-		tok.Expiry = t
-	}
-	newTok, err := conf.TokenSource(ctx, tok).Token()
-	if err != nil {
-		return nil, err
-	}
-
-	// Persist back to metadata; prefer nested token map if present
-	if tokenMap == nil {
-		tokenMap = make(map[string]any)
-	}
-	tokenMap["access_token"] = newTok.AccessToken
-	tokenMap["refresh_token"] = newTok.RefreshToken
-	tokenMap["expiry"] = newTok.Expiry.Format(time.RFC3339)
-	if clientID != "" {
-		tokenMap["client_id"] = clientID
-	}
-	if clientSecret != "" {
-		tokenMap["client_secret"] = clientSecret
-	}
-	if tokenURI != "" {
-		tokenMap["token_uri"] = tokenURI
-	}
-	auth.Metadata["token"] = tokenMap
-
-	// Also mirror top-level access_token for compatibility if previously present
-	if _, ok := auth.Metadata["access_token"]; ok {
-		auth.Metadata["access_token"] = newTok.AccessToken
-	}
 	return auth, nil
 }
 

internal/runtime/executor/gemini_vertex_executor.go

@@ -1,6 +1,6 @@
-// Package executor contains provider executors. This file implements the Vertex AI
+// Package executor provides runtime execution capabilities for various AI service providers.
-// Gemini executor that talks to Google Vertex AI endpoints using service account
+// This file implements the Vertex AI Gemini executor that talks to Google Vertex AI
-// credentials imported by the CLI.
+// endpoints using service account credentials or API keys.
 package executor
 
 import (
@@ -36,20 +36,26 @@ type GeminiVertexExecutor struct {
 	cfg *config.Config
 }
 
-// NewGeminiVertexExecutor constructs the Vertex executor.
+// NewGeminiVertexExecutor creates a new Vertex AI Gemini executor instance.
+//
+// Parameters:
+//   - cfg: The application configuration
+//
+// Returns:
+//   - *GeminiVertexExecutor: A new Vertex AI Gemini executor instance
 func NewGeminiVertexExecutor(cfg *config.Config) *GeminiVertexExecutor {
 	return &GeminiVertexExecutor{cfg: cfg}
 }
 
-// Identifier returns provider key for manager routing.
+// Identifier returns the executor identifier.
 func (e *GeminiVertexExecutor) Identifier() string { return "vertex" }
 
-// PrepareRequest is a no-op for Vertex.
+// PrepareRequest prepares the HTTP request for execution (no-op for Vertex).
 func (e *GeminiVertexExecutor) PrepareRequest(_ *http.Request, _ *cliproxyauth.Auth) error {
 	return nil
 }
 
-// Execute handles non-streaming requests.
+// Execute performs a non-streaming request to the Vertex AI API.
 func (e *GeminiVertexExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
 	// Try API key authentication first
 	apiKey, baseURL := vertexAPICreds(auth)
@@ -67,7 +73,7 @@ func (e *GeminiVertexExecutor) Execute(ctx context.Context, auth *cliproxyauth.A
 	return e.executeWithAPIKey(ctx, auth, req, opts, apiKey, baseURL)
 }
 
-// ExecuteStream handles SSE streaming for Vertex.
+// ExecuteStream performs a streaming request to the Vertex AI API.
 func (e *GeminiVertexExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (stream <-chan cliproxyexecutor.StreamChunk, err error) {
 	// Try API key authentication first
 	apiKey, baseURL := vertexAPICreds(auth)
@@ -85,7 +91,7 @@ func (e *GeminiVertexExecutor) ExecuteStream(ctx context.Context, auth *cliproxy
 	return e.executeStreamWithAPIKey(ctx, auth, req, opts, apiKey, baseURL)
 }
 
-// CountTokens calls Vertex countTokens endpoint.
+// CountTokens counts tokens for the given request using the Vertex AI API.
 func (e *GeminiVertexExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
 	// Try API key authentication first
 	apiKey, baseURL := vertexAPICreds(auth)
@@ -103,185 +109,7 @@ func (e *GeminiVertexExecutor) CountTokens(ctx context.Context, auth *cliproxyau
 	return e.countTokensWithAPIKey(ctx, auth, req, opts, apiKey, baseURL)
 }
 
-// countTokensWithServiceAccount handles token counting using service account credentials.
+// Refresh refreshes the authentication credentials (no-op for Vertex).
-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.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
-		if budgetOverride != nil {
-			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
-			budgetOverride = &norm
-		}
-		translatedReq = util.ApplyGeminiThinkingConfig(translatedReq, budgetOverride, includeOverride)
-	}
-	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, upstreamModel, "countTokens")
-
-	httpReq, errNewReq := http.NewRequestWithContext(respCtx, http.MethodPost, url, bytes.NewReader(translatedReq))
-	if errNewReq != nil {
-		return cliproxyexecutor.Response{}, errNewReq
-	}
-	httpReq.Header.Set("Content-Type", "application/json")
-	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)
-		return cliproxyexecutor.Response{}, statusErr{code: 500, msg: "internal server error"}
-	}
-	applyGeminiHeaders(httpReq, auth)
-
-	var authID, authLabel, authType, authValue string
-	if auth != nil {
-		authID = auth.ID
-		authLabel = auth.Label
-		authType, authValue = auth.AccountInfo()
-	}
-	recordAPIRequest(ctx, e.cfg, upstreamRequestLog{
-		URL:       url,
-		Method:    http.MethodPost,
-		Headers:   httpReq.Header.Clone(),
-		Body:      translatedReq,
-		Provider:  e.Identifier(),
-		AuthID:    authID,
-		AuthLabel: authLabel,
-		AuthType:  authType,
-		AuthValue: authValue,
-	})
-
-	httpClient := newProxyAwareHTTPClient(ctx, e.cfg, auth, 0)
-	httpResp, errDo := httpClient.Do(httpReq)
-	if errDo != nil {
-		recordAPIResponseError(ctx, e.cfg, errDo)
-		return cliproxyexecutor.Response{}, errDo
-	}
-	defer func() {
-		if errClose := httpResp.Body.Close(); errClose != nil {
-			log.Errorf("vertex executor: close response body error: %v", errClose)
-		}
-	}()
-	recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
-	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
-		b, _ := io.ReadAll(httpResp.Body)
-		appendAPIResponseChunk(ctx, e.cfg, b)
-		log.Debugf("request error, error status: %d, error body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), b))
-		return cliproxyexecutor.Response{}, statusErr{code: httpResp.StatusCode, msg: string(b)}
-	}
-	data, errRead := io.ReadAll(httpResp.Body)
-	if errRead != nil {
-		recordAPIResponseError(ctx, e.cfg, errRead)
-		return cliproxyexecutor.Response{}, errRead
-	}
-	appendAPIResponseChunk(ctx, e.cfg, data)
-	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
-		log.Debugf("request error, error status: %d, error body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), data))
-		return cliproxyexecutor.Response{}, statusErr{code: httpResp.StatusCode, msg: string(data)}
-	}
-	count := gjson.GetBytes(data, "totalTokens").Int()
-	out := sdktranslator.TranslateTokenCount(ctx, to, from, count, data)
-	return cliproxyexecutor.Response{Payload: []byte(out)}, nil
-}
-
-// 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.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
-		if budgetOverride != nil {
-			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
-			budgetOverride = &norm
-		}
-		translatedReq = util.ApplyGeminiThinkingConfig(translatedReq, budgetOverride, includeOverride)
-	}
-	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")
-
-	// 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, "countTokens")
-
-	httpReq, errNewReq := http.NewRequestWithContext(respCtx, http.MethodPost, url, bytes.NewReader(translatedReq))
-	if errNewReq != nil {
-		return cliproxyexecutor.Response{}, errNewReq
-	}
-	httpReq.Header.Set("Content-Type", "application/json")
-	if apiKey != "" {
-		httpReq.Header.Set("x-goog-api-key", apiKey)
-	}
-	applyGeminiHeaders(httpReq, auth)
-
-	var authID, authLabel, authType, authValue string
-	if auth != nil {
-		authID = auth.ID
-		authLabel = auth.Label
-		authType, authValue = auth.AccountInfo()
-	}
-	recordAPIRequest(ctx, e.cfg, upstreamRequestLog{
-		URL:       url,
-		Method:    http.MethodPost,
-		Headers:   httpReq.Header.Clone(),
-		Body:      translatedReq,
-		Provider:  e.Identifier(),
-		AuthID:    authID,
-		AuthLabel: authLabel,
-		AuthType:  authType,
-		AuthValue: authValue,
-	})
-
-	httpClient := newProxyAwareHTTPClient(ctx, e.cfg, auth, 0)
-	httpResp, errDo := httpClient.Do(httpReq)
-	if errDo != nil {
-		recordAPIResponseError(ctx, e.cfg, errDo)
-		return cliproxyexecutor.Response{}, errDo
-	}
-	defer func() {
-		if errClose := httpResp.Body.Close(); errClose != nil {
-			log.Errorf("vertex executor: close response body error: %v", errClose)
-		}
-	}()
-	recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
-	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
-		b, _ := io.ReadAll(httpResp.Body)
-		appendAPIResponseChunk(ctx, e.cfg, b)
-		log.Debugf("request error, error status: %d, error body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), b))
-		return cliproxyexecutor.Response{}, statusErr{code: httpResp.StatusCode, msg: string(b)}
-	}
-	data, errRead := io.ReadAll(httpResp.Body)
-	if errRead != nil {
-		recordAPIResponseError(ctx, e.cfg, errRead)
-		return cliproxyexecutor.Response{}, errRead
-	}
-	appendAPIResponseChunk(ctx, e.cfg, data)
-	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
-		log.Debugf("request error, error status: %d, error body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), data))
-		return cliproxyexecutor.Response{}, statusErr{code: httpResp.StatusCode, msg: string(data)}
-	}
-	count := gjson.GetBytes(data, "totalTokens").Int()
-	out := sdktranslator.TranslateTokenCount(ctx, to, from, count, data)
-	return cliproxyexecutor.Response{Payload: []byte(out)}, nil
-}
-
-// Refresh is a no-op for service account based credentials.
 func (e *GeminiVertexExecutor) Refresh(_ context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
 	return auth, nil
 }
@@ -579,7 +407,7 @@ func (e *GeminiVertexExecutor) executeStreamWithServiceAccount(ctx context.Conte
 			}
 		}()
 		scanner := bufio.NewScanner(httpResp.Body)
-		scanner.Buffer(nil, 52_428_800) // 50MB
+		scanner.Buffer(nil, streamScannerBuffer)
 		var param any
 		for scanner.Scan() {
 			line := scanner.Bytes()
@@ -696,7 +524,7 @@ func (e *GeminiVertexExecutor) executeStreamWithAPIKey(ctx context.Context, auth
 			}
 		}()
 		scanner := bufio.NewScanner(httpResp.Body)
-		scanner.Buffer(nil, 52_428_800) // 50MB
+		scanner.Buffer(nil, streamScannerBuffer)
 		var param any
 		for scanner.Scan() {
 			line := scanner.Bytes()
@@ -722,6 +550,184 @@ func (e *GeminiVertexExecutor) executeStreamWithAPIKey(ctx context.Context, auth
 	return stream, nil
 }
 
+// countTokensWithServiceAccount counts tokens 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.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
+		if budgetOverride != nil {
+			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
+			budgetOverride = &norm
+		}
+		translatedReq = util.ApplyGeminiThinkingConfig(translatedReq, budgetOverride, includeOverride)
+	}
+	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, upstreamModel, "countTokens")
+
+	httpReq, errNewReq := http.NewRequestWithContext(respCtx, http.MethodPost, url, bytes.NewReader(translatedReq))
+	if errNewReq != nil {
+		return cliproxyexecutor.Response{}, errNewReq
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+	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)
+		return cliproxyexecutor.Response{}, statusErr{code: 500, msg: "internal server error"}
+	}
+	applyGeminiHeaders(httpReq, auth)
+
+	var authID, authLabel, authType, authValue string
+	if auth != nil {
+		authID = auth.ID
+		authLabel = auth.Label
+		authType, authValue = auth.AccountInfo()
+	}
+	recordAPIRequest(ctx, e.cfg, upstreamRequestLog{
+		URL:       url,
+		Method:    http.MethodPost,
+		Headers:   httpReq.Header.Clone(),
+		Body:      translatedReq,
+		Provider:  e.Identifier(),
+		AuthID:    authID,
+		AuthLabel: authLabel,
+		AuthType:  authType,
+		AuthValue: authValue,
+	})
+
+	httpClient := newProxyAwareHTTPClient(ctx, e.cfg, auth, 0)
+	httpResp, errDo := httpClient.Do(httpReq)
+	if errDo != nil {
+		recordAPIResponseError(ctx, e.cfg, errDo)
+		return cliproxyexecutor.Response{}, errDo
+	}
+	defer func() {
+		if errClose := httpResp.Body.Close(); errClose != nil {
+			log.Errorf("vertex executor: close response body error: %v", errClose)
+		}
+	}()
+	recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
+	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
+		b, _ := io.ReadAll(httpResp.Body)
+		appendAPIResponseChunk(ctx, e.cfg, b)
+		log.Debugf("request error, error status: %d, error body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), b))
+		return cliproxyexecutor.Response{}, statusErr{code: httpResp.StatusCode, msg: string(b)}
+	}
+	data, errRead := io.ReadAll(httpResp.Body)
+	if errRead != nil {
+		recordAPIResponseError(ctx, e.cfg, errRead)
+		return cliproxyexecutor.Response{}, errRead
+	}
+	appendAPIResponseChunk(ctx, e.cfg, data)
+	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
+		log.Debugf("request error, error status: %d, error body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), data))
+		return cliproxyexecutor.Response{}, statusErr{code: httpResp.StatusCode, msg: string(data)}
+	}
+	count := gjson.GetBytes(data, "totalTokens").Int()
+	out := sdktranslator.TranslateTokenCount(ctx, to, from, count, data)
+	return cliproxyexecutor.Response{Payload: []byte(out)}, nil
+}
+
+// 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.ResolveThinkingConfigFromMetadata(req.Model, req.Metadata); ok && util.ModelSupportsThinking(req.Model) {
+		if budgetOverride != nil {
+			norm := util.NormalizeThinkingBudget(req.Model, *budgetOverride)
+			budgetOverride = &norm
+		}
+		translatedReq = util.ApplyGeminiThinkingConfig(translatedReq, budgetOverride, includeOverride)
+	}
+	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")
+
+	// 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, "countTokens")
+
+	httpReq, errNewReq := http.NewRequestWithContext(respCtx, http.MethodPost, url, bytes.NewReader(translatedReq))
+	if errNewReq != nil {
+		return cliproxyexecutor.Response{}, errNewReq
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+	if apiKey != "" {
+		httpReq.Header.Set("x-goog-api-key", apiKey)
+	}
+	applyGeminiHeaders(httpReq, auth)
+
+	var authID, authLabel, authType, authValue string
+	if auth != nil {
+		authID = auth.ID
+		authLabel = auth.Label
+		authType, authValue = auth.AccountInfo()
+	}
+	recordAPIRequest(ctx, e.cfg, upstreamRequestLog{
+		URL:       url,
+		Method:    http.MethodPost,
+		Headers:   httpReq.Header.Clone(),
+		Body:      translatedReq,
+		Provider:  e.Identifier(),
+		AuthID:    authID,
+		AuthLabel: authLabel,
+		AuthType:  authType,
+		AuthValue: authValue,
+	})
+
+	httpClient := newProxyAwareHTTPClient(ctx, e.cfg, auth, 0)
+	httpResp, errDo := httpClient.Do(httpReq)
+	if errDo != nil {
+		recordAPIResponseError(ctx, e.cfg, errDo)
+		return cliproxyexecutor.Response{}, errDo
+	}
+	defer func() {
+		if errClose := httpResp.Body.Close(); errClose != nil {
+			log.Errorf("vertex executor: close response body error: %v", errClose)
+		}
+	}()
+	recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
+	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
+		b, _ := io.ReadAll(httpResp.Body)
+		appendAPIResponseChunk(ctx, e.cfg, b)
+		log.Debugf("request error, error status: %d, error body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), b))
+		return cliproxyexecutor.Response{}, statusErr{code: httpResp.StatusCode, msg: string(b)}
+	}
+	data, errRead := io.ReadAll(httpResp.Body)
+	if errRead != nil {
+		recordAPIResponseError(ctx, e.cfg, errRead)
+		return cliproxyexecutor.Response{}, errRead
+	}
+	appendAPIResponseChunk(ctx, e.cfg, data)
+	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
+		log.Debugf("request error, error status: %d, error body: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), data))
+		return cliproxyexecutor.Response{}, statusErr{code: httpResp.StatusCode, msg: string(data)}
+	}
+	count := gjson.GetBytes(data, "totalTokens").Int()
+	out := sdktranslator.TranslateTokenCount(ctx, to, from, count, data)
+	return cliproxyexecutor.Response{Payload: []byte(out)}, nil
+}
+
 // vertexCreds extracts project, location and raw service account JSON from auth metadata.
 func vertexCreds(a *cliproxyauth.Auth) (projectID, location string, serviceAccountJSON []byte, err error) {
 	if a == nil || a.Metadata == nil {