diff --git a/internal/core/local_runtime/setup_python_environment.go b/internal/core/local_runtime/setup_python_environment.go
index 50324c491..05164f0c4 100644
--- a/internal/core/local_runtime/setup_python_environment.go
+++ b/internal/core/local_runtime/setup_python_environment.go
@@ -197,15 +197,7 @@ func (p *LocalPluginRuntime) installDependencies(
 	parent.SetAttributes(attribute.String("uv.path", uvPath), attribute.StringSlice("uv.args", args))
 	cmd.Env = append(cmd.Env, "VIRTUAL_ENV="+virtualEnvPath, "PATH="+os.Getenv("PATH"))
 	cmd.Env = append(cmd.Env, "UV_CACHE_DIR="+uvCacheDir)
-	if p.appConfig.HttpProxy != "" {
-		cmd.Env = append(cmd.Env, fmt.Sprintf("HTTP_PROXY=%s", p.appConfig.HttpProxy))
-	}
-	if p.appConfig.HttpsProxy != "" {
-		cmd.Env = append(cmd.Env, fmt.Sprintf("HTTPS_PROXY=%s", p.appConfig.HttpsProxy))
-	}
-	if p.appConfig.NoProxy != "" {
-		cmd.Env = append(cmd.Env, fmt.Sprintf("NO_PROXY=%s", p.appConfig.NoProxy))
-	}
+	cmd.Env = append(cmd.Env, p.appConfig.ProxyEnv()...)
 	cmd.Dir = p.State.WorkingPath
 
 	// get stdout and stderr
diff --git a/internal/core/local_runtime/subprocess.go b/internal/core/local_runtime/subprocess.go
index 37d9855ab..3f5e0d40b 100644
--- a/internal/core/local_runtime/subprocess.go
+++ b/internal/core/local_runtime/subprocess.go
@@ -33,15 +33,7 @@ func (r *LocalPluginRuntime) getInstanceCmd() (*exec.Cmd, error) {
 	}
 
 	cmd.Env = cmd.Environ()
-	if r.appConfig.HttpsProxy != "" {
-		cmd.Env = append(cmd.Env, fmt.Sprintf("HTTPS_PROXY=%s", r.appConfig.HttpsProxy))
-	}
-	if r.appConfig.HttpProxy != "" {
-		cmd.Env = append(cmd.Env, fmt.Sprintf("HTTP_PROXY=%s", r.appConfig.HttpProxy))
-	}
-	if r.appConfig.NoProxy != "" {
-		cmd.Env = append(cmd.Env, fmt.Sprintf("NO_PROXY=%s", r.appConfig.NoProxy))
-	}
+	cmd.Env = append(cmd.Env, r.appConfig.ProxyEnv()...)
 	cmd.Env = append(cmd.Env, "INSTALL_METHOD=local", "PATH="+os.Getenv("PATH"))
 	cmd.Dir = r.State.WorkingPath
 	return cmd, nil
diff --git a/internal/types/app/config_test.go b/internal/types/app/config_test.go
index b2592ffe8..d7790927b 100644
--- a/internal/types/app/config_test.go
+++ b/internal/types/app/config_test.go
@@ -4,6 +4,7 @@ import (
 	"crypto/tls"
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 
 	"github.com/kelseyhightower/envconfig"
@@ -86,6 +87,61 @@ func TestConfigRedisKeyPrefixField(t *testing.T) {
 	assert.Equal(t, "enterprise-a", cfg.RedisKeyPrefix)
 }
 
+func TestConfigProxyLowercaseFallbacks(t *testing.T) {
+	t.Setenv("HTTP_PROXY", "")
+	t.Setenv("HTTPS_PROXY", "")
+	t.Setenv("NO_PROXY", "")
+	t.Setenv("http_proxy", "http://lowercase-http:8080")
+	t.Setenv("https_proxy", "http://lowercase-https:8443")
+	t.Setenv("no_proxy", "localhost,127.0.0.1")
+
+	cfg := Config{}
+	require.NoError(t, envconfig.Process("", &cfg))
+	cfg.SetDefault()
+
+	assert.Equal(t, "http://lowercase-http:8080", cfg.HttpProxy)
+	assert.Equal(t, "http://lowercase-https:8443", cfg.HttpsProxy)
+	assert.Equal(t, "localhost,127.0.0.1", cfg.NoProxy)
+}
+
+func TestConfigProxyUppercaseTakesPrecedence(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("Windows environment variables are case-insensitive")
+	}
+
+	t.Setenv("HTTP_PROXY", "http://uppercase-http:8080")
+	t.Setenv("http_proxy", "http://lowercase-http:8080")
+	t.Setenv("HTTPS_PROXY", "http://uppercase-https:8443")
+	t.Setenv("https_proxy", "http://lowercase-https:8443")
+	t.Setenv("NO_PROXY", "internal")
+	t.Setenv("no_proxy", "localhost")
+
+	cfg := Config{}
+	require.NoError(t, envconfig.Process("", &cfg))
+	cfg.SetDefault()
+
+	assert.Equal(t, "http://uppercase-http:8080", cfg.HttpProxy)
+	assert.Equal(t, "http://uppercase-https:8443", cfg.HttpsProxy)
+	assert.Equal(t, "internal", cfg.NoProxy)
+}
+
+func TestConfigProxyEnvIncludesUppercaseAndLowercase(t *testing.T) {
+	cfg := Config{
+		HttpProxy:  "http://proxy-http:8080",
+		HttpsProxy: "http://proxy-https:8443",
+		NoProxy:    "localhost",
+	}
+
+	assert.ElementsMatch(t, []string{
+		"HTTP_PROXY=http://proxy-http:8080",
+		"http_proxy=http://proxy-http:8080",
+		"HTTPS_PROXY=http://proxy-https:8443",
+		"https_proxy=http://proxy-https:8443",
+		"NO_PROXY=localhost",
+		"no_proxy=localhost",
+	}, cfg.ProxyEnv())
+}
+
 func TestRedisTLSConfig(t *testing.T) {
 	tests := []struct {
 		name           string
diff --git a/internal/types/app/default.go b/internal/types/app/default.go
index eedaaa0c3..53d63618c 100644
--- a/internal/types/app/default.go
+++ b/internal/types/app/default.go
@@ -6,6 +6,7 @@ import (
 )
 
 func (config *Config) SetDefault() {
+	config.SetProxyEnvFallbacks()
 	switch config.DBType {
 	case DB_TYPE_OCEANBASE, DB_TYPE_SEEKDB:
 		config.DBType = DB_TYPE_MYSQL
diff --git a/internal/types/app/proxy.go b/internal/types/app/proxy.go
new file mode 100644
index 000000000..5d707dc31
--- /dev/null
+++ b/internal/types/app/proxy.go
@@ -0,0 +1,49 @@
+package app
+
+import (
+	"fmt"
+	"os"
+)
+
+func (config *Config) SetProxyEnvFallbacks() {
+	if config == nil {
+		return
+	}
+
+	if config.HttpProxy == "" {
+		config.HttpProxy = os.Getenv("http_proxy")
+	}
+	if config.HttpsProxy == "" {
+		config.HttpsProxy = os.Getenv("https_proxy")
+	}
+	if config.NoProxy == "" {
+		config.NoProxy = os.Getenv("no_proxy")
+	}
+}
+
+func (config *Config) ProxyEnv() []string {
+	if config == nil {
+		return nil
+	}
+
+	env := []string{}
+	if config.HttpProxy != "" {
+		env = append(env,
+			fmt.Sprintf("HTTP_PROXY=%s", config.HttpProxy),
+			fmt.Sprintf("http_proxy=%s", config.HttpProxy),
+		)
+	}
+	if config.HttpsProxy != "" {
+		env = append(env,
+			fmt.Sprintf("HTTPS_PROXY=%s", config.HttpsProxy),
+			fmt.Sprintf("https_proxy=%s", config.HttpsProxy),
+		)
+	}
+	if config.NoProxy != "" {
+		env = append(env,
+			fmt.Sprintf("NO_PROXY=%s", config.NoProxy),
+			fmt.Sprintf("no_proxy=%s", config.NoProxy),
+		)
+	}
+	return env
+}