diff --git a/internal/runtime/executor/helps/proxy_helpers.go b/internal/runtime/executor/helps/proxy_helpers.go
index 022bc65c17..8a3f7ab19b 100644
--- a/internal/runtime/executor/helps/proxy_helpers.go
+++ b/internal/runtime/executor/helps/proxy_helpers.go
@@ -12,6 +12,22 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+func init() {
+	if transport, ok := http.DefaultTransport.(*http.Transport); ok && transport != nil {
+		applyTransportTuning(transport)
+	}
+}
+
+func applyTransportTuning(t *http.Transport) {
+	if t == nil {
+		return
+	}
+	t.MaxIdleConns = 200
+	t.MaxIdleConnsPerHost = 20
+	t.IdleConnTimeout = 90 * time.Second
+	t.ForceAttemptHTTP2 = true
+}
+
 // NewProxyAwareHTTPClient creates an HTTP client with proper proxy configuration priority:
 // 1. Use auth.ProxyURL if configured (highest priority)
 // 2. Use cfg.ProxyURL if auth proxy is not configured
@@ -46,6 +62,7 @@ func NewProxyAwareHTTPClient(ctx context.Context, cfg *config.Config, auth *clip
 	if proxyURL != "" {
 		transport := buildProxyTransport(proxyURL)
 		if transport != nil {
+			applyTransportTuning(transport)
 			httpClient.Transport = transport
 			return httpClient
 		}
diff --git a/internal/runtime/executor/helps/proxy_helpers_test.go b/internal/runtime/executor/helps/proxy_helpers_test.go
index 3311716765..6d29d249a4 100644
--- a/internal/runtime/executor/helps/proxy_helpers_test.go
+++ b/internal/runtime/executor/helps/proxy_helpers_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"net/http"
 	"testing"
+	"time"
 
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
 	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
@@ -28,3 +29,58 @@ func TestNewProxyAwareHTTPClientDirectBypassesGlobalProxy(t *testing.T) {
 		t.Fatal("expected direct transport to disable proxy function")
 	}
 }
+
+func assertTransportTuned(t *testing.T, transport *http.Transport, label string) {
+	t.Helper()
+	if transport.MaxIdleConns != 200 {
+		t.Errorf("%s: MaxIdleConns = %d, want 200", label, transport.MaxIdleConns)
+	}
+	if transport.MaxIdleConnsPerHost != 20 {
+		t.Errorf("%s: MaxIdleConnsPerHost = %d, want 20", label, transport.MaxIdleConnsPerHost)
+	}
+	if transport.IdleConnTimeout != 90*time.Second {
+		t.Errorf("%s: IdleConnTimeout = %v, want 90s", label, transport.IdleConnTimeout)
+	}
+	if !transport.ForceAttemptHTTP2 {
+		t.Errorf("%s: ForceAttemptHTTP2 = false, want true", label)
+	}
+}
+
+func TestNewProxyAwareHTTPClient_DefaultTransportTuned(t *testing.T) {
+	t.Parallel()
+
+	transport, ok := http.DefaultTransport.(*http.Transport)
+	if !ok {
+		t.Skip("http.DefaultTransport is not *http.Transport")
+	}
+
+	assertTransportTuned(t, transport, "global tuned transport")
+
+	client := NewProxyAwareHTTPClient(context.Background(), nil, nil, 0)
+	if client.Transport != nil {
+		t.Error("expected NewProxyAwareHTTPClient to return nil transport when no proxy is configured to use http.DefaultTransport")
+	}
+}
+
+func TestNewProxyAwareHTTPClient_ContextRoundTripperReused(t *testing.T) {
+	t.Parallel()
+
+	original := &http.Transport{
+		MaxIdleConns:        1,
+		MaxIdleConnsPerHost: 1,
+		IdleConnTimeout:     time.Second,
+		ForceAttemptHTTP2:   false,
+	}
+
+	ctx := context.WithValue(context.Background(), "cliproxy.roundtripper", original)
+	client := NewProxyAwareHTTPClient(ctx, nil, nil, 0)
+
+	if client.Transport != original {
+		t.Error("expected original context RoundTripper to be reused without cloning")
+	}
+
+	// Verify the original transport was NOT mutated by NewProxyAwareHTTPClient
+	if original.MaxIdleConns != 1 || original.MaxIdleConnsPerHost != 1 {
+		t.Error("original transport was mutated, but it should be preserved as-is when provided via context")
+	}
+}