diff --git a/internal/api/handlers/management/auth_files.go b/internal/api/handlers/management/auth_files.go
index 4318b972..a0bff059 100644
--- a/internal/api/handlers/management/auth_files.go
+++ b/internal/api/handlers/management/auth_files.go
@@ -508,6 +508,10 @@ func (h *Handler) DeleteAuthFile(c *gin.Context) {
 				}
 			}
 			if err = os.Remove(full); err == nil {
+				if errDel := h.deleteTokenRecord(ctx, full); errDel != nil {
+					c.JSON(500, gin.H{"error": errDel.Error()})
+					return
+				}
 				deleted++
 				h.disableAuth(ctx, full)
 			}
@@ -534,6 +538,10 @@ func (h *Handler) DeleteAuthFile(c *gin.Context) {
 		}
 		return
 	}
+	if err := h.deleteTokenRecord(ctx, full); err != nil {
+		c.JSON(500, gin.H{"error": err.Error()})
+		return
+	}
 	h.disableAuth(ctx, full)
 	c.JSON(200, gin.H{"status": "ok"})
 }
@@ -640,9 +648,20 @@ func (h *Handler) disableAuth(ctx context.Context, id string) {
 	}
 }
 
-func (h *Handler) saveTokenRecord(ctx context.Context, record *coreauth.Auth) (string, error) {
-	if record == nil {
-		return "", fmt.Errorf("token record is nil")
+func (h *Handler) deleteTokenRecord(ctx context.Context, path string) error {
+	if strings.TrimSpace(path) == "" {
+		return fmt.Errorf("auth path is empty")
+	}
+	store := h.tokenStoreWithBaseDir()
+	if store == nil {
+		return fmt.Errorf("token store unavailable")
+	}
+	return store.Delete(ctx, path)
+}
+
+func (h *Handler) tokenStoreWithBaseDir() coreauth.Store {
+	if h == nil {
+		return nil
 	}
 	store := h.tokenStore
 	if store == nil {
@@ -654,6 +673,17 @@ func (h *Handler) saveTokenRecord(ctx context.Context, record *coreauth.Auth) (s
 			dirSetter.SetBaseDir(h.cfg.AuthDir)
 		}
 	}
+	return store
+}
+
+func (h *Handler) saveTokenRecord(ctx context.Context, record *coreauth.Auth) (string, error) {
+	if record == nil {
+		return "", fmt.Errorf("token record is nil")
+	}
+	store := h.tokenStoreWithBaseDir()
+	if store == nil {
+		return "", fmt.Errorf("token store unavailable")
+	}
 	return store.Save(ctx, record)
 }
 
diff --git a/internal/runtime/executor/gemini_vertex_executor.go b/internal/runtime/executor/gemini_vertex_executor.go
index 4e606390..94be62cb 100644
--- a/internal/runtime/executor/gemini_vertex_executor.go
+++ b/internal/runtime/executor/gemini_vertex_executor.go
@@ -22,6 +22,7 @@ import (
 	log "github.com/sirupsen/logrus"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
+	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 )
 
@@ -89,7 +90,7 @@ func (e *GeminiVertexExecutor) Execute(ctx context.Context, auth *cliproxyauth.A
 		return resp, errNewReq
 	}
 	httpReq.Header.Set("Content-Type", "application/json")
-	if token, errTok := vertexAccessToken(ctx, saJSON); errTok == nil && token != "" {
+	if token, errTok := vertexAccessToken(ctx, e.cfg, auth, saJSON); errTok == nil && token != "" {
 		httpReq.Header.Set("Authorization", "Bearer "+token)
 	} else if errTok != nil {
 		log.Errorf("vertex executor: access token error: %v", errTok)
@@ -184,7 +185,7 @@ func (e *GeminiVertexExecutor) ExecuteStream(ctx context.Context, auth *cliproxy
 		return nil, errNewReq
 	}
 	httpReq.Header.Set("Content-Type", "application/json")
-	if token, errTok := vertexAccessToken(ctx, saJSON); errTok == nil && token != "" {
+	if token, errTok := vertexAccessToken(ctx, e.cfg, auth, saJSON); errTok == nil && token != "" {
 		httpReq.Header.Set("Authorization", "Bearer "+token)
 	} else if errTok != nil {
 		log.Errorf("vertex executor: access token error: %v", errTok)
@@ -295,7 +296,7 @@ func (e *GeminiVertexExecutor) CountTokens(ctx context.Context, auth *cliproxyau
 		return cliproxyexecutor.Response{}, errNewReq
 	}
 	httpReq.Header.Set("Content-Type", "application/json")
-	if token, errTok := vertexAccessToken(ctx, saJSON); errTok == nil && token != "" {
+	if token, errTok := vertexAccessToken(ctx, e.cfg, auth, saJSON); errTok == nil && token != "" {
 		httpReq.Header.Set("Authorization", "Bearer "+token)
 	} else if errTok != nil {
 		log.Errorf("vertex executor: access token error: %v", errTok)
@@ -407,7 +408,10 @@ func vertexBaseURL(location string) string {
 	return fmt.Sprintf("https://%s-aiplatform.googleapis.com", loc)
 }
 
-func vertexAccessToken(ctx context.Context, saJSON []byte) (string, error) {
+func vertexAccessToken(ctx context.Context, cfg *config.Config, auth *cliproxyauth.Auth, saJSON []byte) (string, error) {
+	if httpClient := newProxyAwareHTTPClient(ctx, cfg, auth, 0); httpClient != nil {
+		ctx = context.WithValue(ctx, oauth2.HTTPClient, httpClient)
+	}
 	// Use cloud-platform scope for Vertex AI.
 	creds, errCreds := google.CredentialsFromJSON(ctx, saJSON, "https://www.googleapis.com/auth/cloud-platform")
 	if errCreds != nil {