feat: Add Support for Proxy Based Npm Interceptor (#87)

* feat: Add experimental proxy based npm interceptor

* refactor: Analysis cache

* ci: Add E2E for npm proxy

* fix: Handle dry-run in proxy flow

* fix: Handle special case for scope package name

* fix: Misc fixes

* fix: Code review fixes

* fix: Code review fixes

* refactor: Reusable code into base registry interceptor

* Pause npm process during user confirmation (#90)

* pause npm process when prompting user for confirmation

* disable progress bar

* fix logging and close chan on return

* update use of deprecated field

* refactor: Separation of concerns for handling process state

* fix: Safe permission for cert file

* fix: Handle nil check for interaction hook

* fix: Add test for base registry

* Fix goreleaser for windows build (#93)

* introduce platform specific process control

* rename common.go to common_flow.go

* feat: Add support for pause resume on windows

* fix: Code review fixes

* test: Add confirmation handler tests

---------

Co-authored-by: Sahil Bansal <bansalsahil315@gmail.com>

.github/workflows/ci.yml

@@ -35,6 +35,24 @@ jobs:
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
 
+  test-windows:
+    timeout-minutes: 15
+    runs-on: windows-latest
+    steps:
+      - name: Checkout Source
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+
+      - name: Set up Go
+        uses: actions/setup-go@0aaccfd150d50ccaeb58ebd88d36e91967a5f35b # v5
+        with:
+          go-version-file: go.mod
+
+      - name: Build and Test
+        run: |
+          go mod tidy
+          go build -o pmg.exe main.go
+          go test -v ./internal/flows/...
+
   e2e-test:
     runs-on: ubuntu-latest
     timeout-minutes: 15

.github/workflows/pmg-e2e.yml

@@ -101,6 +101,49 @@ jobs:
           test -d node_modules/lodash
           cd .. && rm -rf npm-test
 
+      - name: Test NPM - Experimental Proxy Mode
+        run: |
+          echo "Testing NPM with experimental proxy-based interception..."
+          mkdir npm-proxy-test && cd npm-proxy-test
+          pmg npm init -y
+
+          echo "Testing proxy mode single package installation..."
+          pmg --experimental-proxy-mode npm install express@5.2.1
+          pmg --experimental-proxy-mode npm install lodash@4.17.21
+
+          # Verification: packages installed via proxy mode
+          test -d node_modules/express
+          test -d node_modules/lodash
+          grep -q '"express"' package.json
+          grep -q '"lodash"' package.json
+
+          echo "Testing proxy mode manifest installation..."
+          rm -rf node_modules package-lock.json
+          pmg --experimental-proxy-mode npm install
+
+          # Verification: manifest install via proxy mode works
+          test -f package-lock.json
+          test -d node_modules/express
+          test -d node_modules/lodash
+
+          echo "Testing proxy mode with scoped package..."
+          pmg --experimental-proxy-mode npm install @types/node@18.0.0
+
+          # Verification: scoped package installed via proxy
+          test -d node_modules/@types
+          test -d node_modules/@types/node
+          grep -q '"@types/node"' package.json
+
+          echo "Testing proxy mode dry-run (should not create files)..."
+          rm -rf node_modules package-lock.json
+          pmg --experimental-proxy-mode --dry-run npm install
+
+          # Verification: dry-run doesn't create files even in proxy mode
+          test ! -d node_modules
+          test ! -f package-lock.json
+
+          cd .. && rm -rf npm-proxy-test
+
       - name: Test PNPM - Single Package & Manifest
         run: |
           echo "Testing PNPM single package installation..."

README.md

@@ -64,13 +64,16 @@ uv pip install <package-name>
     - [Recommended: Automated Setup](#recommended-automated-setup)
     - [Alternative: Manual Commands](#alternative-manual-commands)
     - [Lockfile Installation](#lockfile-installation)
+    - [Active Scanning](#active-scanning)
     - [Silent Mode](#silent-mode)
     - [Dry Run](#dry-run)
     - [Verbose Mode](#verbose-mode)
     - [Debugging](#debugging)
   - [Environment Variables](#environment-variables)
+    - [PMG\_INSECURE\_INSTALLATION](#pmg_insecure_installation)
   - [🤝 Contributing](#-contributing)
   - [🚫 Limitations](#-limitations)
+  - [Telemetry](#telemetry)
 
 ## 🔥 Features
 
@@ -85,7 +88,7 @@ uv pip install <package-name>
 PMG supports the following package managers:
 
 | Package Manager | Status   | Command                                                  |
-| --------------- | --------- | -------------------------------------------------------- |
+| --------------- | -------- | -------------------------------------------------------- |
 | `npm`           | ✅ Active | `pmg npm install <package>`                              |
 | `pnpm`          | ✅ Active | `pmg pnpm add <package>`                                 |
 | `bun`           | ✅ Active | `pmg bun add <package>`                                  |
@@ -309,6 +312,28 @@ from non-PyPI locations.
 
 </details>
 
+<details>
+<summary>Windows support for experimental proxy mode</summary>
+
+PMG's experimental proxy mode (enabled with `--experimental-proxy-mode` flag) is supported on Windows
+with the following considerations:
+
+**Process Suspension**: PMG uses the Windows NT API (NtSuspendProcess/NtResumeProcess) to pause the
+package manager during security prompts. This prevents console output from being mixed with interactive
+prompts. While this API is widely used by tools like Process Explorer and is stable, it has some known
+limitations:
+
+- **Race condition**: Threads created during suspension are not suspended (very unlikely for brief suspensions)
+- **Permission requirements**: Requires Windows Vista or later (all currently supported Windows versions)
+- **Antivirus detection**: Some antivirus software may flag the use of NtSuspendProcess as suspicious behavior,
+  which is a false positive (PMG only uses it to pause its own child processes during user interaction)
+
+**Fallback Behavior**: If process suspension fails (e.g., due to insufficient permissions), PMG continues
+with the security prompt but console output from the package manager may be mixed with the prompt text.
+This doesn't affect security functionality.
+
+</details>
+
 ## Telemetry
 
 `pmg` collects anonymous telemetry to help us understand how it is used and

cmd/npm/npm.go

@@ -51,5 +51,9 @@ func executeNpmFlow(ctx context.Context, args []string) error {
 		return fmt.Errorf("failed to create dependency resolver: %w", err)
 	}
 
+	if config.Config.ExperimentalProxyMode {
+		return flows.ProxyFlow(packageManager, packageResolver).Run(ctx, args, parsedCommand)
+	}
+
 	return flows.Common(packageManager, packageResolver).Run(ctx, args, parsedCommand)
 }

config/cobra.go

@@ -19,4 +19,6 @@ func ApplyCobraFlags(cmd *cobra.Command) {
 		globalConfig.Config.Paranoid, "Perform active scanning of unknown packages (slow)")
 	cmd.PersistentFlags().BoolVar(&globalConfig.Config.SkipEventLogging, "skip-event-log",
 		globalConfig.Config.SkipEventLogging, "Skip event logging")
+	cmd.PersistentFlags().BoolVar(&globalConfig.Config.ExperimentalProxyMode, "experimental-proxy-mode",
+		globalConfig.Config.ExperimentalProxyMode, "Use experimental proxy-based interception (EXPERIMENTAL)")
 }

config/config.go

@@ -52,6 +52,10 @@ type Config struct {
 
 	// EventLogRetentionDays is the number of days to retain event logs.
 	EventLogRetentionDays int `mapstructure:"event_log_retention_days"`
+
+	// ExperimentalProxyMode enables experimental proxy-based package interception.
+	// When enabled, PMG starts a proxy server and intercepts package manager requests in real-time.
+	ExperimentalProxyMode bool `mapstructure:"experimental_proxy_mode"`
 }
 
 // TrustedPackage is a package that is trusted by the user and will be ignored by the security guardrails.
@@ -106,6 +110,7 @@ func DefaultConfig() RuntimeConfig {
 			Paranoid:               false,
 			EventLogRetentionDays:  7,
 			SkipEventLogging:       false,
+			ExperimentalProxyMode:  false,
 			TrustedPackages:        []TrustedPackage{},
 		},
 		DryRun:               false,

config/config.template.yml

@@ -23,6 +23,13 @@ skip_event_logging: false
 # This is the number of days to retain event logs.
 event_log_retention_days: 7
 
+# Experimental proxy mode. Default is false.
+# When enabled, PMG uses an experimental proxy-based interception approach instead of the
+# default guard-based analysis. The proxy intercepts package manager requests in real-time
+# and analyzes packages as they are downloaded. This is an experimental feature and may not
+# work in all environments.
+experimental_proxy_mode: false
+
 # Trusted packages are packages that are trusted by the user and will be ignored by the security guardrails.
 # This is useful for packages that are known to be safe and are used in the application.
 # Example:

internal/eventlog/eventlog_test.go

@@ -26,21 +26,17 @@ func TestLoggerInitialization(t *testing.T) {
 
 	// Initialize logger
 	err := InitializeWithDir(logDir)
-	if err != nil {
+	assert.NoError(t, err, "Failed to initialize logger")
-		t.Fatalf("Failed to initialize logger: %v", err)
-	}
 	defer Close()
 
 	// Check that directory was created
-	if _, err := os.Stat(logDir); os.IsNotExist(err) {
+	_, err = os.Stat(logDir)
-		t.Errorf("Log directory was not created: %s", logDir)
+	assert.False(t, os.IsNotExist(err), "Log directory was not created: %s", logDir)
-	}
 
 	// Check that log file was created
 	expectedLogFile := filepath.Join(logDir, time.Now().Format("20060102")+"-pmg.log")
-	if _, err := os.Stat(expectedLogFile); os.IsNotExist(err) {
+	_, err = os.Stat(expectedLogFile)
-		t.Errorf("Log file was not created: %s", expectedLogFile)
+	assert.False(t, os.IsNotExist(err), "Log file was not created: %s", expectedLogFile)
-	}
 }
 
 func TestLogEvent(t *testing.T) {
@@ -50,9 +46,7 @@ func TestLogEvent(t *testing.T) {
 
 	// Initialize logger
 	err := reinitializeForTest(logDir)
-	if err != nil {
+	assert.NoError(t, err, "Failed to initialize logger")
-		t.Fatalf("Failed to initialize logger: %v", err)
-	}
 	defer Close()
 
 	// Log an event
@@ -68,31 +62,21 @@ func TestLogEvent(t *testing.T) {
 	}
 
 	err = LogEvent(event)
-	if err != nil {
+	assert.NoError(t, err, "Failed to log event")
-		t.Fatalf("Failed to log event: %v", err)
-	}
 
 	// Read the log file and verify the event was written
 	logFilePath := filepath.Join(logDir, time.Now().Format("20060102")+"-pmg.log")
 	data, err := os.ReadFile(logFilePath)
-	if err != nil {
+	assert.NoError(t, err, "Failed to read log file")
-		t.Fatalf("Failed to read log file: %v", err)
-	}
 
 	// Parse the JSON
 	var loggedEvent Event
 	err = json.Unmarshal(data, &loggedEvent)
-	if err != nil {
+	assert.NoError(t, err, "Failed to parse logged event")
-		t.Fatalf("Failed to parse logged event: %v", err)
-	}
 
 	// Verify the event
-	if loggedEvent.EventType != EventTypeMalwareBlocked {
+	assert.Equal(t, EventTypeMalwareBlocked, loggedEvent.EventType)
-		t.Errorf("Expected event type %s, got %s", EventTypeMalwareBlocked, loggedEvent.EventType)
+	assert.Equal(t, "evil-package", loggedEvent.PackageName)
-	}
-	if loggedEvent.PackageName != "evil-package" {
-		t.Errorf("Expected package name 'evil-package', got '%s'", loggedEvent.PackageName)
-	}
 }
 
 func TestLogMalwareBlocked(t *testing.T) {
@@ -102,9 +86,7 @@ func TestLogMalwareBlocked(t *testing.T) {
 
 	// Initialize logger
 	err := reinitializeForTest(logDir)
-	if err != nil {
+	assert.NoError(t, err, "Failed to initialize logger")
-		t.Fatalf("Failed to initialize logger: %v", err)
-	}
 	defer Close()
 
 	// Log malware blocked event
@@ -113,25 +95,15 @@ func TestLogMalwareBlocked(t *testing.T) {
 	// Read and verify
 	logFilePath := filepath.Join(logDir, time.Now().Format("20060102")+"-pmg.log")
 	data, err := os.ReadFile(logFilePath)
-	if err != nil {
+	assert.NoError(t, err, "Failed to read log file")
-		t.Fatalf("Failed to read log file: %v", err)
-	}
 
 	var event Event
 	err = json.Unmarshal(data, &event)
-	if err != nil {
+	assert.NoError(t, err, "Failed to parse event")
-		t.Fatalf("Failed to parse event: %v", err)
-	}
 
-	if event.EventType != EventTypeMalwareBlocked {
+	assert.Equal(t, EventTypeMalwareBlocked, event.EventType)
-		t.Errorf("Expected event type %s, got %s", EventTypeMalwareBlocked, event.EventType)
+	assert.Equal(t, "malicious-pkg", event.PackageName)
-	}
+	assert.Equal(t, "pypi", event.Ecosystem)
-	if event.PackageName != "malicious-pkg" {
-		t.Errorf("Expected package 'malicious-pkg', got '%s'", event.PackageName)
-	}
-	if event.Ecosystem != "pypi" {
-		t.Errorf("Expected ecosystem 'pypi', got '%s'", event.Ecosystem)
-	}
 }
 
 func TestInitializeWithFile(t *testing.T) {
@@ -148,9 +120,7 @@ func TestInitializeWithFile(t *testing.T) {
 	// Reset for custom file
 	once = sync.Once{}
 	err = InitializeWithFile(logFile)
-	if err != nil {
+	assert.NoError(t, err, "Failed to initialize logger with file")
-		t.Fatalf("Failed to initialize logger with file: %v", err)
-	}
 	defer Close()
 
 	// Log an event
@@ -163,33 +133,20 @@ func TestInitializeWithFile(t *testing.T) {
 	}
 
 	err = LogEvent(event)
-	if err != nil {
+	assert.NoError(t, err, "Failed to log event")
-		t.Fatalf("Failed to log event: %v", err)
-	}
 
 	// Verify the custom log file was created and contains the event
-	if _, err := os.Stat(logFile); os.IsNotExist(err) {
+	_, err = os.Stat(logFile)
-		t.Errorf("Custom log file was not created: %s", logFile)
+	assert.False(t, os.IsNotExist(err), "Custom log file was not created: %s", logFile)
-	}
 
 	data, err := os.ReadFile(logFile)
-	if err != nil {
+	assert.NoError(t, err, "Failed to read custom log file")
-		t.Fatalf("Failed to read custom log file: %v", err)
+	assert.NotEmpty(t, data, "Custom log file is empty")
-	}
-
-	if len(data) == 0 {
-		t.Error("Custom log file is empty")
-	}
 
 	var loggedEvent Event
 	err = json.Unmarshal(data, &loggedEvent)
-	if err != nil {
+	assert.NoError(t, err, "Failed to parse logged event")
-		t.Fatalf("Failed to parse logged event: %v", err)
+	assert.Equal(t, "test-package", loggedEvent.PackageName)
-	}
-
-	if loggedEvent.PackageName != "test-package" {
-		t.Errorf("Expected package 'test-package', got '%s'", loggedEvent.PackageName)
-	}
 }
 
 func TestCleanupOldLogs(t *testing.T) {
@@ -197,38 +154,28 @@ func TestCleanupOldLogs(t *testing.T) {
 	tmpDir := t.TempDir()
 	logDir := filepath.Join(tmpDir, ".pmg", "logs")
 	err := os.MkdirAll(logDir, 0755)
-	if err != nil {
+	assert.NoError(t, err, "Failed to create log directory")
-		t.Fatalf("Failed to create log directory: %v", err)
-	}
 
 	// Create old log files
 	oldDate := time.Now().AddDate(0, 0, -10)
 	oldLogFile := filepath.Join(logDir, oldDate.Format("20060102")+"-pmg.log")
 	err = os.WriteFile(oldLogFile, []byte("old log"), 0644)
-	if err != nil {
+	assert.NoError(t, err, "Failed to create old log file")
-		t.Fatalf("Failed to create old log file: %v", err)
-	}
 
 	// Change the modification time to make it appear old
 	oldTime := time.Now().AddDate(0, 0, -10)
 	err = os.Chtimes(oldLogFile, oldTime, oldTime)
-	if err != nil {
+	assert.NoError(t, err, "Failed to change file time")
-		t.Fatalf("Failed to change file time: %v", err)
-	}
 
 	// Create a recent log file
 	recentLogFile := filepath.Join(logDir, time.Now().Format("20060102")+"-pmg.log")
 	err = os.WriteFile(recentLogFile, []byte("recent log"), 0644)
-	if err != nil {
+	assert.NoError(t, err, "Failed to create recent log file")
-		t.Fatalf("Failed to create recent log file: %v", err)
-	}
 
 	// Initialize logger (which triggers cleanup)
 	logger := &fileWithRotationLogger{}
 	err = logger.init(logDir)
-	if err != nil {
+	assert.NoError(t, err, "Failed to initialize logger")
-		t.Fatalf("Failed to initialize logger: %v", err)
-	}
 
 	defer logger.Close()
 
@@ -236,12 +183,10 @@ func TestCleanupOldLogs(t *testing.T) {
 	time.Sleep(100 * time.Millisecond)
 
 	// Check that old file was deleted
-	if _, err := os.Stat(oldLogFile); !os.IsNotExist(err) {
+	_, err = os.Stat(oldLogFile)
-		t.Error("Old log file should have been deleted")
+	assert.True(t, os.IsNotExist(err), "Old log file should have been deleted")
-	}
 
 	// Check that recent file still exists
-	if _, err := os.Stat(recentLogFile); os.IsNotExist(err) {
+	_, err = os.Stat(recentLogFile)
-		t.Error("Recent log file should still exist")
+	assert.False(t, os.IsNotExist(err), "Recent log file should still exist")
-	}
 }

internal/flows/process_control_unix.go

@@ -0,0 +1,33 @@
+//go:build !windows
+// +build !windows
+
+package flows
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func platformPauseProcess(cmd *exec.Cmd) error {
+	if cmd == nil || cmd.Process == nil {
+		return nil
+	}
+
+	if err := cmd.Process.Signal(syscall.SIGSTOP); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func platformResumeProcess(cmd *exec.Cmd) error {
+	if cmd == nil || cmd.Process == nil {
+		return nil
+	}
+
+	if err := cmd.Process.Signal(syscall.SIGCONT); err != nil {
+		return err
+	}
+
+	return nil
+}

internal/flows/process_control_windows.go

@@ -0,0 +1,78 @@
+//go:build windows
+// +build windows
+
+package flows
+
+import (
+	"fmt"
+	"os/exec"
+
+	"golang.org/x/sys/windows"
+)
+
+var (
+	modntdll             = windows.NewLazySystemDLL("ntdll.dll")
+	procNtSuspendProcess = modntdll.NewProc("NtSuspendProcess")
+	procNtResumeProcess  = modntdll.NewProc("NtResumeProcess")
+)
+
+// platformPauseProcess suspends the process using Windows NT API.
+//
+// Known limitations:
+// - Race condition: threads created during suspension are not suspended
+// - Remote thread injection still possible (very rare)
+//
+// For PMG's use case (brief suspension during user prompts), these limitations
+// are acceptable.
+//
+// References:
+// - gopsutil: https://github.com/shirou/gopsutil/blob/master/process/process_windows.go
+// - Analysis: https://github.com/diversenok/Suspending-Techniques
+func platformPauseProcess(cmd *exec.Cmd) error {
+	if cmd == nil || cmd.Process == nil {
+		return nil
+	}
+
+	handle, err := windows.OpenProcess(
+		windows.PROCESS_SUSPEND_RESUME,
+		false,
+		uint32(cmd.Process.Pid),
+	)
+	if err != nil {
+		return fmt.Errorf("failed to open process for suspension: %w", err)
+	}
+
+	defer windows.CloseHandle(handle)
+
+	r1, _, _ := procNtSuspendProcess.Call(uintptr(handle))
+	if r1 != 0 {
+		return fmt.Errorf("NtSuspendProcess failed with NTSTATUS=0x%.8X", r1)
+	}
+
+	return nil
+}
+
+// platformResumeProcess resumes a suspended process using Windows NT API.
+func platformResumeProcess(cmd *exec.Cmd) error {
+	if cmd == nil || cmd.Process == nil {
+		return nil
+	}
+
+	handle, err := windows.OpenProcess(
+		windows.PROCESS_SUSPEND_RESUME,
+		false,
+		uint32(cmd.Process.Pid),
+	)
+	if err != nil {
+		return fmt.Errorf("failed to open process for resumption: %w", err)
+	}
+
+	defer windows.CloseHandle(handle)
+
+	r1, _, _ := procNtResumeProcess.Call(uintptr(handle))
+	if r1 != 0 {
+		return fmt.Errorf("NtResumeProcess failed with NTSTATUS=0x%.8X", r1)
+	}
+
+	return nil
+}

internal/flows/process_control_windows_test.go

@@ -0,0 +1,114 @@
+//go:build windows
+// +build windows
+
+package flows
+
+import (
+	"os/exec"
+	"runtime"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPlatformPauseResumeProcess(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		t.Skip("Windows-only test")
+	}
+
+	cmd := exec.Command("ping", "127.0.0.1", "-n", "60")
+	err := cmd.Start()
+	assert.NoError(t, err)
+
+	defer cmd.Process.Kill()
+
+	time.Sleep(100 * time.Millisecond)
+
+	err = platformPauseProcess(cmd)
+	assert.NoError(t, err)
+
+	time.Sleep(500 * time.Millisecond)
+
+	err = platformResumeProcess(cmd)
+	assert.NoError(t, err)
+}
+
+func TestPlatformPauseProcessNil(t *testing.T) {
+	err := platformPauseProcess(nil)
+	assert.NoError(t, err)
+}
+
+func TestPlatformResumeProcessNil(t *testing.T) {
+	err := platformResumeProcess(nil)
+	assert.NoError(t, err)
+}
+
+func TestPlatformPauseProcessNilProcess(t *testing.T) {
+	cmd := exec.Command("ping", "127.0.0.1")
+	err := platformPauseProcess(cmd)
+	assert.NoError(t, err)
+}
+
+func TestPlatformResumeProcessNilProcess(t *testing.T) {
+	cmd := exec.Command("ping", "127.0.0.1")
+
+	err := platformResumeProcess(cmd)
+	assert.NoError(t, err)
+}
+
+func TestPlatformPauseProcessExited(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		t.Skip("Windows-only test")
+	}
+
+	cmd := exec.Command("cmd", "/c", "exit 0")
+	err := cmd.Start()
+	assert.NoError(t, err)
+
+	defer cmd.Process.Kill()
+
+	err = platformPauseProcess(cmd)
+	assert.NoError(t, err)
+}
+
+func TestPlatformResumeProcessExited(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		t.Skip("Windows-only test")
+	}
+
+	cmd := exec.Command("cmd", "/c", "exit 0")
+	err := cmd.Start()
+	assert.NoError(t, err)
+
+	defer cmd.Process.Kill()
+
+	err = platformResumeProcess(cmd)
+	assert.NoError(t, err)
+}
+
+func TestPlatformPauseResumeMultipleTimes(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		t.Skip("Windows-only test")
+	}
+
+	cmd := exec.Command("ping", "127.0.0.1", "-n", "60")
+	err := cmd.Start()
+	assert.NoError(t, err)
+
+	defer cmd.Process.Kill()
+
+	time.Sleep(100 * time.Millisecond)
+
+	for i := 0; i < 3; i++ {
+		err = platformPauseProcess(cmd)
+		assert.NoError(t, err)
+
+		time.Sleep(100 * time.Millisecond)
+
+		err = platformResumeProcess(cmd)
+		assert.NoError(t, err)
+
+		time.Sleep(100 * time.Millisecond)
+	}
+}

internal/flows/proxy_flow.go

@@ -0,0 +1,279 @@
+package flows
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"time"
+
+	"github.com/safedep/dry/log"
+	"github.com/safedep/pmg/analyzer"
+	"github.com/safedep/pmg/config"
+	"github.com/safedep/pmg/guard"
+	"github.com/safedep/pmg/internal/ui"
+	"github.com/safedep/pmg/packagemanager"
+	"github.com/safedep/pmg/proxy"
+	"github.com/safedep/pmg/proxy/certmanager"
+	"github.com/safedep/pmg/proxy/interceptors"
+)
+
+type proxyFlow struct {
+	pm              packagemanager.PackageManager
+	packageResolver packagemanager.PackageResolver
+}
+
+// ProxyFlow creates a new proxy-based flow for package manager protection
+func ProxyFlow(pm packagemanager.PackageManager, packageResolver packagemanager.PackageResolver) *proxyFlow {
+	return &proxyFlow{
+		pm:              pm,
+		packageResolver: packageResolver,
+	}
+}
+
+// Run executes the proxy-based flow
+func (f *proxyFlow) Run(ctx context.Context, args []string, parsedCmd *packagemanager.ParsedCommand) error {
+	cfg := config.Get()
+
+	// Check if dry-run mode is enabled
+	if cfg.DryRun {
+		ui.SetStatus("Running in dry-run mode (proxy mode)")
+		log.Infof("Dry-run mode: Would execute %s with experimental proxy protection", f.pm.Name())
+		log.Infof("Dry-run mode: Command would be: %s %v", parsedCmd.Command.Exe, parsedCmd.Command.Args)
+		ui.ClearStatus()
+		return nil
+	}
+
+	ui.SetStatus("Initializing experimental proxy mode...")
+
+	// Setup CA certificate for MITM
+	caCert, caCertPath, err := f.setupCACertificate()
+	if err != nil {
+		return fmt.Errorf("failed to setup CA certificate for proxy mode: %w", err)
+	}
+
+	defer func() {
+		// Clean up temporary CA certificate file
+		if caCertPath != "" {
+			if err := os.Remove(caCertPath); err != nil {
+				log.Errorf("Failed to remove CA certificate file: %v", err)
+			}
+		}
+	}()
+
+	// Create certificate manager
+	certMgr, err := f.createCertificateManager(caCert)
+	if err != nil {
+		return fmt.Errorf("failed to create certificate manager: %w", err)
+	}
+
+	// Create analyzer
+	malysisAnalyzer, err := f.createAnalyzer()
+	if err != nil {
+		return fmt.Errorf("failed to create analyzer: %w", err)
+	}
+
+	// Create analysis cache
+	cache := interceptors.NewInMemoryAnalysisCache()
+
+	// Create confirmation channel and start confirmation handler
+	confirmationChan := make(chan *interceptors.ConfirmationRequest, 10)
+	defer close(confirmationChan)
+
+	// Create interaction callbacks for user prompts
+	interaction := guard.PackageManagerGuardInteraction{
+		SetStatus:                ui.SetStatus,
+		ClearStatus:              ui.ClearStatus,
+		ShowWarning:              ui.ShowWarning,
+		GetConfirmationOnMalware: ui.GetConfirmationOnMalware,
+		Block:                    ui.Block,
+	}
+
+	// Get the ecosystem from the package manager
+	ecosystem := f.pm.Ecosystem()
+
+	// Check if proxy mode is supported for this ecosystem
+	if !interceptors.IsSupported(ecosystem) {
+		return fmt.Errorf("proxy mode is not supported for %s", ecosystem.String())
+	}
+
+	// Create ecosystem-specific interceptor using factory
+	factory := interceptors.NewInterceptorFactory(malysisAnalyzer, cache, confirmationChan, interaction)
+	interceptor, err := factory.CreateInterceptor(ecosystem)
+	if err != nil {
+		return fmt.Errorf("failed to create interceptor for %s: %w", ecosystem.String(), err)
+	}
+
+	log.Debugf("Created %s interceptor for ecosystem %s", interceptor.Name(), ecosystem.String())
+
+	// Create and start proxy server
+	proxyServer, proxyAddr, err := f.createAndStartProxyServer(certMgr, interceptor)
+	if err != nil {
+		return fmt.Errorf("failed to start proxy server: %w", err)
+	}
+
+	// Ensure proxy is stopped on exit
+	defer func() {
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+
+		if err := proxyServer.Stop(shutdownCtx); err != nil {
+			log.Errorf("Failed to stop proxy server: %v", err)
+		}
+	}()
+
+	ui.ClearStatus()
+	log.Infof("Proxy server started on %s", proxyAddr)
+	log.Infof("Running %s with proxy protection enabled", f.pm.Name())
+
+	// Execute the package manager command with proxy environment variables
+	return f.executeWithProxy(ctx, parsedCmd, proxyAddr, caCertPath, confirmationChan, interaction)
+}
+
+// setupCACertificate generates or loads a CA certificate for MITM
+func (f *proxyFlow) setupCACertificate() (*certmanager.Certificate, string, error) {
+	log.Debugf("Generating CA certificate for proxy MITM")
+
+	// Generate CA certificate
+	caConfig := certmanager.DefaultCertManagerConfig()
+	caCert, err := certmanager.GenerateCA(caConfig)
+	if err != nil {
+		return nil, "", fmt.Errorf("failed to generate CA certificate: %w", err)
+	}
+
+	// Write CA certificate to temporary file for package managers to trust
+	tempDir := os.TempDir()
+	caCertPath := filepath.Join(tempDir, fmt.Sprintf("pmg-ca-cert-%d.pem", os.Getpid()))
+
+	if err := os.WriteFile(caCertPath, caCert.Certificate, 0600); err != nil {
+		return nil, "", fmt.Errorf("failed to write CA certificate to %s: %w", caCertPath, err)
+	}
+
+	log.Debugf("CA certificate written to %s", caCertPath)
+
+	return caCert, caCertPath, nil
+}
+
+// createCertificateManager creates a certificate manager with the given CA certificate
+func (f *proxyFlow) createCertificateManager(caCert *certmanager.Certificate) (certmanager.CertificateManager, error) {
+	caConfig := certmanager.DefaultCertManagerConfig()
+	certMgr, err := certmanager.NewCertificateManagerWithCA(caCert, caConfig)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create certificate manager: %w", err)
+	}
+
+	return certMgr, nil
+}
+
+// createAnalyzer creates the malysis query analyzer
+func (f *proxyFlow) createAnalyzer() (analyzer.PackageVersionAnalyzer, error) {
+	cfg := config.Get()
+
+	// Use paranoid mode (active scan) if enabled, otherwise use query mode
+	if cfg.Config.Paranoid {
+		log.Debugf("Creating malysis active scan analyzer (paranoid mode)")
+		return analyzer.NewMalysisActiveScanAnalyzer(analyzer.DefaultMalysisActiveScanAnalyzerConfig())
+	}
+
+	log.Debugf("Creating malysis query analyzer")
+	return analyzer.NewMalysisQueryAnalyzer(analyzer.MalysisQueryAnalyzerConfig{})
+}
+
+// createAndStartProxyServer creates and starts the proxy server with the given interceptor
+func (f *proxyFlow) createAndStartProxyServer(
+	certMgr certmanager.CertificateManager,
+	interceptor proxy.Interceptor,
+) (proxy.ProxyServer, string, error) {
+	proxyConfig := &proxy.ProxyConfig{
+		ListenAddr:     "127.0.0.1:0",
+		CertManager:    certMgr,
+		EnableMITM:     true,
+		Interceptors:   []proxy.Interceptor{interceptor},
+		ConnectTimeout: 30 * time.Second,
+		RequestTimeout: 5 * time.Minute,
+	}
+
+	proxyServer, err := proxy.NewProxyServer(proxyConfig)
+	if err != nil {
+		return nil, "", fmt.Errorf("failed to create proxy server: %w", err)
+	}
+
+	if err := proxyServer.Start(); err != nil {
+		return nil, "", fmt.Errorf("failed to start proxy server: %w", err)
+	}
+
+	proxyAddr := proxyServer.Address()
+	if proxyAddr == "" {
+		return nil, "", fmt.Errorf("proxy server started but address is empty")
+	}
+
+	return proxyServer, proxyAddr, nil
+}
+
+// executeWithProxy executes the package manager command with proxy environment variables
+func (f *proxyFlow) executeWithProxy(ctx context.Context, parsedCmd *packagemanager.ParsedCommand,
+	proxyAddr, caCertPath string, confirmationChan chan *interceptors.ConfirmationRequest,
+	interaction guard.PackageManagerGuardInteraction,
+) error {
+	// Build proxy URL
+	proxyURL := fmt.Sprintf("http://%s", proxyAddr)
+
+	// Create command
+	cmd := exec.CommandContext(ctx, parsedCmd.Command.Exe, parsedCmd.Command.Args...)
+
+	// Set proxy environment variables. This is what tells the executed command to use the proxy for communication.
+	// However, every package manager has its nuances and may require additional environment variables to be set.
+	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env,
+		fmt.Sprintf("HTTP_PROXY=%s", proxyURL),
+		fmt.Sprintf("HTTPS_PROXY=%s", proxyURL),
+		fmt.Sprintf("NODE_EXTRA_CA_CERTS=%s", caCertPath),
+		fmt.Sprintf("http_proxy=%s", proxyURL),
+		fmt.Sprintf("https_proxy=%s", proxyURL),
+		fmt.Sprintf("SSL_CERT_FILE=%s", caCertPath),
+		fmt.Sprintf("REQUESTS_CA_BUNDLE=%s", caCertPath),
+		fmt.Sprintf("PIP_CERT=%s", caCertPath),
+		fmt.Sprintf("PIP_PROXY=%s", proxyURL),
+		"NPM_CONFIG_PROGRESS=false",
+	)
+
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	log.Debugf("Executing command: %s %v", parsedCmd.Command.Exe, parsedCmd.Command.Args)
+	log.Debugf("Proxy environment: HTTP_PROXY=%s, HTTPS_PROXY=%s, NODE_EXTRA_CA_CERTS=%s", proxyURL, proxyURL, caCertPath)
+
+	// Start confirmation handler in goroutine. Use confirmation hooks to pause and resume the executed
+	// process to prevent stdout and stderr from being mixed up. Pause / resume is on a best effort basis.
+	// We do not consider it a critical error if pause / resume fails.
+	go interceptors.HandleConfirmationRequests(confirmationChan, interaction, &interceptors.ConfirmationHook{
+		BeforeInteraction: func([]*analyzer.PackageVersionAnalysisResult) error {
+			if err := platformPauseProcess(cmd); err != nil {
+				log.Warnf("Failed to pause process for user interaction: %v", err)
+			}
+
+			return nil
+		},
+		AfterInteraction: func([]*analyzer.PackageVersionAnalysisResult, bool) error {
+			if err := platformResumeProcess(cmd); err != nil {
+				log.Warnf("Failed to resume process after user interaction: %v", err)
+			}
+
+			return nil
+		},
+	})
+
+	err := cmd.Run()
+	if err != nil {
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			os.Exit(exitErr.ExitCode())
+		}
+
+		return fmt.Errorf("failed to execute %s: %w", f.pm.Name(), err)
+	}
+
+	log.Debugf("Command completed successfully")
+	return nil
+}

packagemanager/npm.go

@@ -80,10 +80,12 @@ func (npm *npmPackageManager) ParseCommand(args []string) (*ParsedCommand, error
 				ManifestFiles:     []string{},
 			}, nil
 		}
+
 		return &ParsedCommand{
 			Command: command,
 		}, nil
 	}
+
 	// Find the install command position
 	var installCmdIndex = -1
 	for idx, arg := range args {
@@ -108,7 +110,7 @@ func (npm *npmPackageManager) ParseCommand(args []string) (*ParsedCommand, error
 
 	flagSet := pflag.NewFlagSet(npm.Config.CommandName, pflag.ContinueOnError)
 	flagSet.SetOutput(io.Discard)
-	flagSet.ParseErrorsWhitelist.UnknownFlags = true
+	flagSet.ParseErrorsAllowlist.UnknownFlags = true
 
 	switch npm.Config.CommandName {
 	case "npm", "pnpm":

proxy/interceptors/base_registry.go

@@ -0,0 +1,168 @@
+package interceptors
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"time"
+
+	packagev1 "buf.build/gen/go/safedep/api/protocolbuffers/go/safedep/messages/package/v1"
+	"github.com/safedep/dry/log"
+	"github.com/safedep/pmg/analyzer"
+	"github.com/safedep/pmg/guard"
+	"github.com/safedep/pmg/proxy"
+)
+
+// baseRegistryInterceptor provides common functionality for registry interceptors
+// It contains ecosystem-agnostic methods that can be reused by specific registry implementations
+type baseRegistryInterceptor struct {
+	analyzer         analyzer.PackageVersionAnalyzer
+	cache            AnalysisCache
+	confirmationChan chan *ConfirmationRequest
+	interaction      guard.PackageManagerGuardInteraction
+}
+
+var _ proxy.Interceptor = (*baseRegistryInterceptor)(nil)
+
+// Name returns a default name - should be overridden by specific implementations
+func (b *baseRegistryInterceptor) Name() string {
+	return "base-registry-interceptor"
+}
+
+// ShouldIntercept returns false by default - must be overridden by specific implementations
+func (b *baseRegistryInterceptor) ShouldIntercept(ctx *proxy.RequestContext) bool {
+	return false
+}
+
+// HandleRequest returns allow by default - should be overridden by specific implementations
+func (b *baseRegistryInterceptor) HandleRequest(ctx *proxy.RequestContext) (*proxy.InterceptorResponse, error) {
+	return &proxy.InterceptorResponse{Action: proxy.ActionAllow}, nil
+}
+
+// analyzePackage analyzes a package using the configured analyzer with caching
+// This method is ecosystem-agnostic and can be used by any registry interceptor
+func (b *baseRegistryInterceptor) analyzePackage(
+	ctx *proxy.RequestContext,
+	ecosystem packagev1.Ecosystem,
+	packageName string,
+	packageVersion string,
+) (*analyzer.PackageVersionAnalysisResult, error) {
+	if cached, ok := b.cache.Get(ecosystem.String(), packageName, packageVersion); ok {
+		log.Debugf("[%s] Using cached analysis result for %s@%s", ctx.RequestID, packageName, packageVersion)
+		return cached, nil
+	}
+
+	pkgVersion := &packagev1.PackageVersion{
+		Package: &packagev1.Package{
+			Ecosystem: ecosystem,
+			Name:      packageName,
+		},
+		Version: packageVersion,
+	}
+
+	log.Debugf("[%s] Analyzing package %s@%s", ctx.RequestID, packageName, packageVersion)
+
+	analysisCtx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	result, err := b.analyzer.Analyze(analysisCtx, pkgVersion)
+	if err != nil {
+		return nil, fmt.Errorf("analyzer failed: %w", err)
+	}
+
+	b.cache.Set(ecosystem.String(), packageName, packageVersion, result)
+
+	log.Debugf("[%s] Analysis complete for %s@%s: action=%d", ctx.RequestID, packageName, packageVersion, result.Action)
+
+	return result, nil
+}
+
+// handleAnalysisResult processes the analysis result and returns appropriate response action
+// This method is ecosystem agnostic and handles the analysis result uniformly
+func (b *baseRegistryInterceptor) handleAnalysisResult(
+	ctx *proxy.RequestContext,
+	ecosystem packagev1.Ecosystem,
+	packageName string,
+	packageVersion string,
+	result *analyzer.PackageVersionAnalysisResult,
+) (*proxy.InterceptorResponse, error) {
+	switch result.Action {
+	case analyzer.ActionBlock:
+		log.Warnf("[%s] Blocking malicious package %s@%s", ctx.RequestID, packageName, packageVersion)
+
+		message := fmt.Sprintf("Malicious package blocked: %s/%s@%s\n\nReason: %s\n\nReference: %s",
+			ecosystem.String(),
+			packageName, packageVersion,
+			result.Summary,
+			result.ReferenceURL)
+
+		return &proxy.InterceptorResponse{
+			Action:       proxy.ActionBlock,
+			BlockCode:    http.StatusForbidden,
+			BlockMessage: message,
+		}, nil
+
+	case analyzer.ActionConfirm:
+		log.Warnf("[%s] Package %s/%s@%s is suspicious, requesting user confirmation", ctx.RequestID, ecosystem.String(), packageName, packageVersion)
+
+		confirmed, err := b.requestUserConfirmation(ctx, result)
+		if err != nil {
+			log.Errorf("[%s] Failed to get user confirmation: %v", ctx.RequestID, err)
+			return &proxy.InterceptorResponse{
+				Action:       proxy.ActionBlock,
+				BlockCode:    http.StatusForbidden,
+				BlockMessage: fmt.Sprintf("Failed to get user confirmation for suspicious package %s/%s@%s", ecosystem.String(), packageName, packageVersion),
+			}, nil
+		}
+
+		if !confirmed {
+			log.Infof("[%s] User declined installation of suspicious package %s/%s@%s", ctx.RequestID, ecosystem.String(), packageName, packageVersion)
+
+			message := fmt.Sprintf("Installation blocked by user: %s/%s@%s\n\nReason: %s\n\nReference: %s",
+				ecosystem.String(),
+				packageName, packageVersion,
+				result.Summary,
+				result.ReferenceURL)
+
+			return &proxy.InterceptorResponse{
+				Action:       proxy.ActionBlock,
+				BlockCode:    http.StatusForbidden,
+				BlockMessage: message,
+			}, nil
+		}
+
+		log.Infof("[%s] User confirmed installation of suspicious package %s/%s@%s", ctx.RequestID, ecosystem.String(), packageName, packageVersion)
+		return &proxy.InterceptorResponse{Action: proxy.ActionAllow}, nil
+
+	case analyzer.ActionAllow:
+		log.Debugf("[%s] Package %s/%s@%s is safe, allowing request", ctx.RequestID, ecosystem.String(), packageName, packageVersion)
+		return &proxy.InterceptorResponse{Action: proxy.ActionAllow}, nil
+
+	default:
+		log.Warnf("[%s] Unknown analysis action %d for package %s/%s@%s, allowing by default", ctx.RequestID, result.Action, ecosystem.String(), packageName, packageVersion)
+		return &proxy.InterceptorResponse{Action: proxy.ActionAllow}, nil
+	}
+}
+
+// requestUserConfirmation sends a confirmation request and blocks waiting for user response
+func (b *baseRegistryInterceptor) requestUserConfirmation(
+	ctx *proxy.RequestContext,
+	result *analyzer.PackageVersionAnalysisResult,
+) (bool, error) {
+	req := NewConfirmationRequest(result.PackageVersion, result)
+
+	select {
+	case b.confirmationChan <- req:
+	case <-time.After(5 * time.Second):
+		return false, fmt.Errorf("timeout sending confirmation request")
+	}
+
+	// Block waiting for user response
+	// Producer is responsible for closing the response channel to prevent goroutine leaks.
+	select {
+	case confirmed := <-req.ResponseChan:
+		return confirmed, nil
+	case <-time.After(5 * time.Minute):
+		return false, fmt.Errorf("timeout waiting for user confirmation")
+	}
+}

proxy/interceptors/base_registry_test.go

@@ -0,0 +1,161 @@
+package interceptors
+
+import (
+	"net/http"
+	"net/url"
+	"testing"
+	"time"
+
+	packagev1 "buf.build/gen/go/safedep/api/protocolbuffers/go/safedep/messages/package/v1"
+	"github.com/safedep/pmg/analyzer"
+	"github.com/safedep/pmg/guard"
+	"github.com/safedep/pmg/proxy"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBaseRegistryInterceptor_HandleAnalysisResult(t *testing.T) {
+	tests := []struct {
+		name               string
+		ecosystem          packagev1.Ecosystem
+		packageName        string
+		packageVersion     string
+		analysisResult     *analyzer.PackageVersionAnalysisResult
+		userConfirms       bool
+		expectedAction     proxy.ResponseAction
+		expectedBlockCode  int
+		expectBlockMessage bool
+	}{
+		{
+			name:           "ActionBlock - malicious package",
+			ecosystem:      packagev1.Ecosystem_ECOSYSTEM_NPM,
+			packageName:    "malicious-pkg",
+			packageVersion: "1.0.0",
+			analysisResult: &analyzer.PackageVersionAnalysisResult{
+				Action:       analyzer.ActionBlock,
+				Summary:      "Contains known malware",
+				ReferenceURL: "https://example.com/malware-report",
+			},
+			expectedAction:     proxy.ActionBlock,
+			expectedBlockCode:  http.StatusForbidden,
+			expectBlockMessage: true,
+		},
+		{
+			name:           "ActionConfirm - user confirms installation",
+			ecosystem:      packagev1.Ecosystem_ECOSYSTEM_NPM,
+			packageName:    "suspicious-pkg",
+			packageVersion: "2.0.0",
+			analysisResult: &analyzer.PackageVersionAnalysisResult{
+				Action:       analyzer.ActionConfirm,
+				Summary:      "Suspicious behavior detected",
+				ReferenceURL: "https://example.com/suspicious-report",
+			},
+			userConfirms:       true,
+			expectedAction:     proxy.ActionAllow,
+			expectedBlockCode:  0,
+			expectBlockMessage: false,
+		},
+		{
+			name:           "ActionConfirm - user declines installation",
+			ecosystem:      packagev1.Ecosystem_ECOSYSTEM_NPM,
+			packageName:    "suspicious-pkg",
+			packageVersion: "2.0.0",
+			analysisResult: &analyzer.PackageVersionAnalysisResult{
+				Action:       analyzer.ActionConfirm,
+				Summary:      "Suspicious behavior detected",
+				ReferenceURL: "https://example.com/suspicious-report",
+			},
+			userConfirms:       false,
+			expectedAction:     proxy.ActionBlock,
+			expectedBlockCode:  http.StatusForbidden,
+			expectBlockMessage: true,
+		},
+		// Note: Timeout test case is skipped as it would require waiting 5 minutes
+		// The timeout behavior is covered by the implementation but not tested here
+		// to keep tests fast
+		{
+			name:           "ActionAllow - safe package",
+			ecosystem:      packagev1.Ecosystem_ECOSYSTEM_NPM,
+			packageName:    "safe-pkg",
+			packageVersion: "3.0.0",
+			analysisResult: &analyzer.PackageVersionAnalysisResult{
+				Action:       analyzer.ActionAllow,
+				Summary:      "Package is safe",
+				ReferenceURL: "https://example.com/safe-report",
+			},
+			expectedAction:     proxy.ActionAllow,
+			expectedBlockCode:  0,
+			expectBlockMessage: false,
+		},
+		{
+			name:           "ActionUnknown - default to allow",
+			ecosystem:      packagev1.Ecosystem_ECOSYSTEM_NPM,
+			packageName:    "unknown-pkg",
+			packageVersion: "4.0.0",
+			analysisResult: &analyzer.PackageVersionAnalysisResult{
+				Action:       analyzer.ActionUnknown,
+				Summary:      "Unknown action",
+				ReferenceURL: "https://example.com/unknown-report",
+			},
+			expectedAction:     proxy.ActionAllow,
+			expectedBlockCode:  0,
+			expectBlockMessage: false,
+		},
+		{
+			name:           "ActionBlock - pypi ecosystem",
+			ecosystem:      packagev1.Ecosystem_ECOSYSTEM_PYPI,
+			packageName:    "malicious-pypi-pkg",
+			packageVersion: "5.0.0",
+			analysisResult: &analyzer.PackageVersionAnalysisResult{
+				Action:       analyzer.ActionBlock,
+				Summary:      "Malicious PyPI package",
+				ReferenceURL: "https://example.com/pypi-malware",
+			},
+			expectedAction:     proxy.ActionBlock,
+			expectedBlockCode:  http.StatusForbidden,
+			expectBlockMessage: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			confirmationChan := make(chan *ConfirmationRequest, 1)
+			interaction := guard.PackageManagerGuardInteraction{}
+
+			base := &baseRegistryInterceptor{
+				confirmationChan: confirmationChan,
+				interaction:      interaction,
+			}
+
+			parsedURL, _ := url.Parse("https://registry.npmjs.org/test")
+			ctx := &proxy.RequestContext{
+				URL:       parsedURL,
+				Method:    "GET",
+				Headers:   make(http.Header),
+				RequestID: "test-request-id",
+				StartTime: time.Now(),
+				Data:      make(map[string]interface{}),
+			}
+
+			if tt.analysisResult.Action == analyzer.ActionConfirm {
+				go func() {
+					req := <-confirmationChan
+					req.ResponseChan <- tt.userConfirms
+					close(req.ResponseChan)
+				}()
+			}
+
+			response, err := base.handleAnalysisResult(
+				ctx,
+				tt.ecosystem,
+				tt.packageName,
+				tt.packageVersion,
+				tt.analysisResult,
+			)
+
+			assert.NoError(t, err)
+			assert.Equal(t, tt.expectedAction, response.Action)
+			assert.Equal(t, tt.expectedBlockCode, response.BlockCode)
+			assert.Equal(t, tt.expectBlockMessage, response.BlockMessage != "")
+		})
+	}
+}

proxy/interceptors/cache.go

@@ -0,0 +1,90 @@
+package interceptors
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/safedep/pmg/analyzer"
+)
+
+type AnalysisCache interface {
+	// Get retrieves a cached analysis result
+	Get(ecosystem, name, version string) (*analyzer.PackageVersionAnalysisResult, bool)
+
+	// Set stores an analysis result in the cache
+	Set(ecosystem, name, version string, result *analyzer.PackageVersionAnalysisResult)
+}
+
+type inMemoryAnalysisCache struct {
+	mu    sync.RWMutex
+	cache map[string]*analyzer.PackageVersionAnalysisResult
+}
+
+var _ AnalysisCache = (*inMemoryAnalysisCache)(nil)
+
+// NewInMemoryAnalysisCache creates a new in-memory analysis cache
+func NewInMemoryAnalysisCache() *inMemoryAnalysisCache {
+	return &inMemoryAnalysisCache{
+		cache: make(map[string]*analyzer.PackageVersionAnalysisResult),
+	}
+}
+
+// cacheKey generates a cache key from ecosystem, name, and version
+func (c *inMemoryAnalysisCache) cacheKey(ecosystem, name, version string) string {
+	return fmt.Sprintf("%s:%s:%s", ecosystem, name, version)
+}
+
+// Get retrieves a cached analysis result
+// Returns the result and true if found, nil and false if not found
+func (c *inMemoryAnalysisCache) Get(ecosystem, name, version string) (*analyzer.PackageVersionAnalysisResult, bool) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	key := c.cacheKey(ecosystem, name, version)
+	result, ok := c.cache[key]
+	return result, ok
+}
+
+// Set stores an analysis result in the cache
+func (c *inMemoryAnalysisCache) Set(ecosystem, name, version string, result *analyzer.PackageVersionAnalysisResult) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	key := c.cacheKey(ecosystem, name, version)
+	c.cache[key] = result
+}
+
+// Clear removes all entries from the cache
+func (c *inMemoryAnalysisCache) Clear() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.cache = make(map[string]*analyzer.PackageVersionAnalysisResult)
+}
+
+// Size returns the number of entries in the cache
+func (c *inMemoryAnalysisCache) Size() int {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	return len(c.cache)
+}
+
+// Has checks if a cache entry exists for the given package
+func (c *inMemoryAnalysisCache) Has(ecosystem, name, version string) bool {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	key := c.cacheKey(ecosystem, name, version)
+	_, ok := c.cache[key]
+	return ok
+}
+
+// Delete removes a specific entry from the cache
+func (c *inMemoryAnalysisCache) Delete(ecosystem, name, version string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	key := c.cacheKey(ecosystem, name, version)
+	delete(c.cache, key)
+}

proxy/interceptors/cache_test.go

@@ -0,0 +1,334 @@
+package interceptors
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/safedep/pmg/analyzer"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewInMemoryAnalysisCache(t *testing.T) {
+	cache := NewInMemoryAnalysisCache()
+	assert.NotNil(t, cache)
+	assert.NotNil(t, cache.cache)
+	assert.Equal(t, 0, cache.Size())
+}
+
+func TestInMemoryAnalysisCache_SetAndGet(t *testing.T) {
+	tests := []struct {
+		name      string
+		ecosystem string
+		pkgName   string
+		version   string
+		result    *analyzer.PackageVersionAnalysisResult
+	}{
+		{
+			name:      "npm package",
+			ecosystem: "npm",
+			pkgName:   "lodash",
+			version:   "4.17.21",
+			result:    &analyzer.PackageVersionAnalysisResult{},
+		},
+		{
+			name:      "pypi package",
+			ecosystem: "pypi",
+			pkgName:   "requests",
+			version:   "2.28.0",
+			result:    &analyzer.PackageVersionAnalysisResult{},
+		},
+		{
+			name:      "package with special characters",
+			ecosystem: "npm",
+			pkgName:   "@babel/core",
+			version:   "7.20.0",
+			result:    &analyzer.PackageVersionAnalysisResult{},
+		},
+		{
+			name:      "package with empty version",
+			ecosystem: "npm",
+			pkgName:   "test-pkg",
+			version:   "",
+			result:    &analyzer.PackageVersionAnalysisResult{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cache := NewInMemoryAnalysisCache()
+
+			// Set value
+			cache.Set(tt.ecosystem, tt.pkgName, tt.version, tt.result)
+
+			// Get value
+			result, ok := cache.Get(tt.ecosystem, tt.pkgName, tt.version)
+			assert.True(t, ok)
+			assert.Equal(t, tt.result, result)
+		})
+	}
+}
+
+func TestInMemoryAnalysisCache_GetNonExistent(t *testing.T) {
+	cache := NewInMemoryAnalysisCache()
+
+	result, ok := cache.Get("npm", "nonexistent", "1.0.0")
+	assert.False(t, ok)
+	assert.Nil(t, result)
+}
+
+func TestInMemoryAnalysisCache_Has(t *testing.T) {
+	tests := []struct {
+		name      string
+		setup     func(*inMemoryAnalysisCache)
+		ecosystem string
+		pkgName   string
+		version   string
+		want      bool
+	}{
+		{
+			name: "existing entry",
+			setup: func(c *inMemoryAnalysisCache) {
+				c.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+			},
+			ecosystem: "npm",
+			pkgName:   "lodash",
+			version:   "4.17.21",
+			want:      true,
+		},
+		{
+			name:      "non-existing entry",
+			setup:     func(c *inMemoryAnalysisCache) {},
+			ecosystem: "npm",
+			pkgName:   "nonexistent",
+			version:   "1.0.0",
+			want:      false,
+		},
+		{
+			name: "different version",
+			setup: func(c *inMemoryAnalysisCache) {
+				c.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+			},
+			ecosystem: "npm",
+			pkgName:   "lodash",
+			version:   "4.17.20",
+			want:      false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cache := NewInMemoryAnalysisCache()
+			tt.setup(cache)
+
+			got := cache.Has(tt.ecosystem, tt.pkgName, tt.version)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func TestInMemoryAnalysisCache_Delete(t *testing.T) {
+	tests := []struct {
+		name         string
+		setup        func(*inMemoryAnalysisCache)
+		deleteEco    string
+		deletePkg    string
+		deleteVer    string
+		expectedSize int
+		shouldExist  bool
+	}{
+		{
+			name: "delete existing entry",
+			setup: func(c *inMemoryAnalysisCache) {
+				c.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+				c.Set("npm", "axios", "1.0.0", &analyzer.PackageVersionAnalysisResult{})
+			},
+			deleteEco:    "npm",
+			deletePkg:    "lodash",
+			deleteVer:    "4.17.21",
+			expectedSize: 1,
+			shouldExist:  false,
+		},
+		{
+			name: "delete non-existing entry",
+			setup: func(c *inMemoryAnalysisCache) {
+				c.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+			},
+			deleteEco:    "npm",
+			deletePkg:    "nonexistent",
+			deleteVer:    "1.0.0",
+			expectedSize: 1,
+			shouldExist:  false,
+		},
+		{
+			name:         "delete from empty cache",
+			setup:        func(c *inMemoryAnalysisCache) {},
+			deleteEco:    "npm",
+			deletePkg:    "lodash",
+			deleteVer:    "4.17.21",
+			expectedSize: 0,
+			shouldExist:  false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cache := NewInMemoryAnalysisCache()
+			tt.setup(cache)
+
+			cache.Delete(tt.deleteEco, tt.deletePkg, tt.deleteVer)
+
+			assert.Equal(t, tt.expectedSize, cache.Size())
+			assert.Equal(t, tt.shouldExist, cache.Has(tt.deleteEco, tt.deletePkg, tt.deleteVer))
+		})
+	}
+}
+
+func TestInMemoryAnalysisCache_Clear(t *testing.T) {
+	cache := NewInMemoryAnalysisCache()
+
+	// Add multiple entries
+	cache.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+	cache.Set("npm", "axios", "1.0.0", &analyzer.PackageVersionAnalysisResult{})
+	cache.Set("pypi", "requests", "2.28.0", &analyzer.PackageVersionAnalysisResult{})
+
+	assert.Equal(t, 3, cache.Size())
+
+	// Clear cache
+	cache.Clear()
+
+	assert.Equal(t, 0, cache.Size())
+	assert.False(t, cache.Has("npm", "lodash", "4.17.21"))
+	assert.False(t, cache.Has("npm", "axios", "1.0.0"))
+	assert.False(t, cache.Has("pypi", "requests", "2.28.0"))
+}
+
+func TestInMemoryAnalysisCache_Size(t *testing.T) {
+	tests := []struct {
+		name     string
+		setup    func(*inMemoryAnalysisCache)
+		wantSize int
+	}{
+		{
+			name:     "empty cache",
+			setup:    func(c *inMemoryAnalysisCache) {},
+			wantSize: 0,
+		},
+		{
+			name: "single entry",
+			setup: func(c *inMemoryAnalysisCache) {
+				c.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+			},
+			wantSize: 1,
+		},
+		{
+			name: "multiple entries",
+			setup: func(c *inMemoryAnalysisCache) {
+				c.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+				c.Set("npm", "axios", "1.0.0", &analyzer.PackageVersionAnalysisResult{})
+				c.Set("pypi", "requests", "2.28.0", &analyzer.PackageVersionAnalysisResult{})
+			},
+			wantSize: 3,
+		},
+		{
+			name: "overwrite same entry",
+			setup: func(c *inMemoryAnalysisCache) {
+				c.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+				c.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+			},
+			wantSize: 1,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cache := NewInMemoryAnalysisCache()
+			tt.setup(cache)
+
+			assert.Equal(t, tt.wantSize, cache.Size())
+		})
+	}
+}
+
+func TestInMemoryAnalysisCache_CacheKeyUniqueness(t *testing.T) {
+	cache := NewInMemoryAnalysisCache()
+
+	// Add entries with different combinations
+	cache.Set("npm", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+	cache.Set("npm", "lodash", "4.17.20", &analyzer.PackageVersionAnalysisResult{})
+	cache.Set("pypi", "lodash", "4.17.21", &analyzer.PackageVersionAnalysisResult{})
+
+	// All should be unique entries
+	assert.Equal(t, 3, cache.Size())
+	assert.True(t, cache.Has("npm", "lodash", "4.17.21"))
+	assert.True(t, cache.Has("npm", "lodash", "4.17.20"))
+	assert.True(t, cache.Has("pypi", "lodash", "4.17.21"))
+}
+
+func TestInMemoryAnalysisCache_Concurrent(t *testing.T) {
+	cache := NewInMemoryAnalysisCache()
+	const numGoroutines = 100
+	const numOperations = 10
+
+	var wg sync.WaitGroup
+	wg.Add(numGoroutines)
+
+	// Run concurrent operations
+	for i := 0; i < numGoroutines; i++ {
+		go func(id int) {
+			defer wg.Done()
+
+			for j := 0; j < numOperations; j++ {
+				ecosystem := "npm"
+				pkgName := "pkg"
+				version := string(rune('0' + (id % 10)))
+
+				// Mix of operations
+				cache.Set(ecosystem, pkgName, version, &analyzer.PackageVersionAnalysisResult{})
+				cache.Get(ecosystem, pkgName, version)
+				cache.Has(ecosystem, pkgName, version)
+				cache.Size()
+
+				if j%5 == 0 {
+					cache.Delete(ecosystem, pkgName, version)
+				}
+			}
+		}(i)
+	}
+
+	wg.Wait()
+
+	// Cache should be in a valid state (no race conditions)
+	size := cache.Size()
+	assert.GreaterOrEqual(t, size, 0)
+	assert.LessOrEqual(t, size, numGoroutines*numOperations)
+}
+
+func TestInMemoryAnalysisCache_UpdateExistingEntry(t *testing.T) {
+	cache := NewInMemoryAnalysisCache()
+
+	// Set initial value
+	result1 := &analyzer.PackageVersionAnalysisResult{
+		Summary: "First analysis",
+	}
+	cache.Set("npm", "lodash", "4.17.21", result1)
+
+	// Get and verify
+	got1, ok := cache.Get("npm", "lodash", "4.17.21")
+	assert.True(t, ok)
+	assert.Equal(t, result1, got1)
+
+	// Update with new value
+	result2 := &analyzer.PackageVersionAnalysisResult{
+		Summary: "Updated analysis",
+	}
+	cache.Set("npm", "lodash", "4.17.21", result2)
+
+	// Verify updated value
+	got2, ok := cache.Get("npm", "lodash", "4.17.21")
+	assert.True(t, ok)
+	assert.Equal(t, result2, got2)
+	assert.NotEqual(t, result1, result2) // Should be different objects with different values
+
+	// Size should still be 1
+	assert.Equal(t, 1, cache.Size())
+}

proxy/interceptors/confirmation.go

@@ -0,0 +1,95 @@
+package interceptors
+
+import (
+	packagev1 "buf.build/gen/go/safedep/api/protocolbuffers/go/safedep/messages/package/v1"
+	"github.com/safedep/dry/log"
+	"github.com/safedep/pmg/analyzer"
+	"github.com/safedep/pmg/guard"
+)
+
+// ConfirmationRequest represents a request for user confirmation on a suspicious package
+type ConfirmationRequest struct {
+	PackageVersion *packagev1.PackageVersion
+	AnalysisResult *analyzer.PackageVersionAnalysisResult
+
+	// ResponseChan is used to send the user's response back.
+	ResponseChan chan bool
+}
+
+// ConfirmationHook is a set of hooks that can be used to customize the confirmation process.
+type ConfirmationHook struct {
+	// BeforeInteraction is called before the user interaction is started.
+	BeforeInteraction func([]*analyzer.PackageVersionAnalysisResult) error
+
+	// AfterInteraction is called after the user interaction is finished.
+	AfterInteraction func([]*analyzer.PackageVersionAnalysisResult, bool) error
+}
+
+// HandleConfirmationRequests processes confirmation requests sequentially
+// This function should be run in a goroutine and will process requests
+// from the confirmation channel one at a time, blocking on user input.
+//
+// The function will exit when the confirmation channel is closed.
+func HandleConfirmationRequests(confirmationChan chan *ConfirmationRequest,
+	interaction guard.PackageManagerGuardInteraction, hooks *ConfirmationHook) {
+	if hooks == nil {
+		hooks = &ConfirmationHook{}
+	}
+
+	for req := range confirmationChan {
+		func() {
+			// The default response is false ie. user did not confirm the installation.
+			// The code here falls through and eventually sets this flag to true if user
+			// confirms the installation.
+			responseVal := false
+
+			// We must make sure to close the response channel to prevent goroutine leaks.
+			// Idiomatic go suggests that the writer should close the channel.
+			defer func() {
+				req.ResponseChan <- responseVal
+				close(req.ResponseChan)
+			}()
+
+			packageName := req.PackageVersion.GetPackage().GetName()
+			log.Debugf("Processing confirmation request for package %s", packageName)
+
+			// Hook to allow the caller to customize the confirmation process.
+			// Hook failures are non-fatal and will not break the confirmation process.
+			if hooks.BeforeInteraction != nil {
+				if err := hooks.BeforeInteraction([]*analyzer.PackageVersionAnalysisResult{req.AnalysisResult}); err != nil {
+					log.Errorf("Error before interaction for package %s: %v", packageName, err)
+				}
+			}
+
+			// Call the user interaction handler to get confirmation
+			// This blocks waiting for stdin input
+			confirmed, confirmationErr := interaction.GetConfirmationOnMalware([]*analyzer.PackageVersionAnalysisResult{req.AnalysisResult})
+
+			// Must guarantee to call the after interaction hook regardless of the confirmation error.
+			if hooks.AfterInteraction != nil {
+				if err := hooks.AfterInteraction([]*analyzer.PackageVersionAnalysisResult{req.AnalysisResult}, confirmed); err != nil {
+					log.Errorf("Error after interaction for package %s: %v", packageName, err)
+				}
+			}
+
+			if confirmationErr != nil {
+				log.Errorf("Error getting confirmation for package %s: %v", packageName, confirmationErr)
+				return
+			}
+
+			// Set the response value to the user's confirmation
+			responseVal = confirmed
+		}()
+	}
+
+	log.Debugf("Confirmation handler exiting (channel closed)")
+}
+
+// NewConfirmationRequest creates a new confirmation request with a response channel
+func NewConfirmationRequest(pkgVersion *packagev1.PackageVersion, result *analyzer.PackageVersionAnalysisResult) *ConfirmationRequest {
+	return &ConfirmationRequest{
+		PackageVersion: pkgVersion,
+		AnalysisResult: result,
+		ResponseChan:   make(chan bool, 1),
+	}
+}

proxy/interceptors/confirmation_test.go

@@ -0,0 +1,208 @@
+package interceptors
+
+import (
+	"errors"
+	"testing"
+
+	packagev1 "buf.build/gen/go/safedep/api/protocolbuffers/go/safedep/messages/package/v1"
+	"github.com/safedep/pmg/analyzer"
+	"github.com/safedep/pmg/guard"
+	"github.com/stretchr/testify/assert"
+)
+
+func mockPackageVersion(name, version string) *packagev1.PackageVersion {
+	return &packagev1.PackageVersion{
+		Package: &packagev1.Package{Name: name},
+		Version: version,
+	}
+}
+
+func mockAnalysisResult() *analyzer.PackageVersionAnalysisResult {
+	return &analyzer.PackageVersionAnalysisResult{
+		Action:  analyzer.ActionConfirm,
+		Summary: "Test suspicious package",
+	}
+}
+
+func TestHandleConfirmationRequests(t *testing.T) {
+	tests := []struct {
+		name                 string
+		confirmationResponse bool
+		confirmationError    error
+		beforeInteractionErr error
+		afterInteractionErr  error
+		useNilHooks          bool
+		expectedResponse     bool
+		verifyHooksCalled    bool
+	}{
+		{
+			name:                 "user confirms installation",
+			confirmationResponse: true,
+			confirmationError:    nil,
+			useNilHooks:          false,
+			expectedResponse:     true,
+			verifyHooksCalled:    true,
+		},
+		{
+			name:                 "user denies installation",
+			confirmationResponse: false,
+			confirmationError:    nil,
+			useNilHooks:          false,
+			expectedResponse:     false,
+			verifyHooksCalled:    true,
+		},
+		{
+			name:                 "confirmation error returns false",
+			confirmationResponse: false,
+			confirmationError:    errors.New("confirmation failed"),
+			useNilHooks:          false,
+			expectedResponse:     false,
+			verifyHooksCalled:    true,
+		},
+		{
+			name:                 "before interaction hook error is non-fatal",
+			confirmationResponse: true,
+			confirmationError:    nil,
+			beforeInteractionErr: errors.New("before hook failed"),
+			useNilHooks:          false,
+			expectedResponse:     true,
+			verifyHooksCalled:    true,
+		},
+		{
+			name:                 "after interaction hook error is non-fatal",
+			confirmationResponse: true,
+			confirmationError:    nil,
+			afterInteractionErr:  errors.New("after hook failed"),
+			useNilHooks:          false,
+			expectedResponse:     true,
+			verifyHooksCalled:    true,
+		},
+		{
+			name:                 "nil hooks does not panic",
+			confirmationResponse: true,
+			confirmationError:    nil,
+			useNilHooks:          true,
+			expectedResponse:     true,
+			verifyHooksCalled:    false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			beforeCalled := false
+			afterCalled := false
+			var afterConfirmedParam bool
+
+			interaction := guard.PackageManagerGuardInteraction{
+				GetConfirmationOnMalware: func(results []*analyzer.PackageVersionAnalysisResult) (bool, error) {
+					assert.Len(t, results, 1)
+					return tt.confirmationResponse, tt.confirmationError
+				},
+			}
+
+			var hooks *ConfirmationHook
+			if !tt.useNilHooks {
+				hooks = &ConfirmationHook{
+					BeforeInteraction: func(results []*analyzer.PackageVersionAnalysisResult) error {
+						beforeCalled = true
+						assert.Len(t, results, 1)
+						return tt.beforeInteractionErr
+					},
+					AfterInteraction: func(results []*analyzer.PackageVersionAnalysisResult, confirmed bool) error {
+						afterCalled = true
+						afterConfirmedParam = confirmed
+						assert.Len(t, results, 1)
+						return tt.afterInteractionErr
+					},
+				}
+			}
+
+			confirmationChan := make(chan *ConfirmationRequest, 1)
+			go HandleConfirmationRequests(confirmationChan, interaction, hooks)
+
+			pkgVersion := mockPackageVersion("test-package", "1.0.0")
+			analysisResult := mockAnalysisResult()
+			analysisResult.PackageVersion = pkgVersion
+			req := NewConfirmationRequest(pkgVersion, analysisResult)
+			confirmationChan <- req
+
+			response := <-req.ResponseChan
+
+			assert.Equal(t, tt.expectedResponse, response)
+
+			if tt.verifyHooksCalled {
+				assert.True(t, beforeCalled, "BeforeInteraction hook should be called")
+				assert.True(t, afterCalled, "AfterInteraction hook should be called")
+				if tt.confirmationError == nil {
+					assert.Equal(t, tt.confirmationResponse, afterConfirmedParam,
+						"AfterInteraction should receive correct confirmation status")
+				}
+			} else {
+				assert.False(t, beforeCalled, "BeforeInteraction hook should not be called when hooks are nil")
+				assert.False(t, afterCalled, "AfterInteraction hook should not be called when hooks are nil")
+			}
+
+			close(confirmationChan)
+		})
+	}
+}
+
+func TestHandleConfirmationRequests_MultipleSequential(t *testing.T) {
+	processedPackages := []string{}
+
+	interaction := guard.PackageManagerGuardInteraction{
+		GetConfirmationOnMalware: func(results []*analyzer.PackageVersionAnalysisResult) (bool, error) {
+			pkgName := results[0].PackageVersion.GetPackage().GetName()
+			processedPackages = append(processedPackages, pkgName)
+			return true, nil
+		},
+	}
+
+	confirmationChan := make(chan *ConfirmationRequest, 3)
+	go HandleConfirmationRequests(confirmationChan, interaction, nil)
+
+	pkgVersion1 := mockPackageVersion("package-1", "1.0.0")
+	analysisResult1 := mockAnalysisResult()
+	analysisResult1.PackageVersion = pkgVersion1
+	req1 := NewConfirmationRequest(pkgVersion1, analysisResult1)
+
+	pkgVersion2 := mockPackageVersion("package-2", "1.0.0")
+	analysisResult2 := mockAnalysisResult()
+	analysisResult2.PackageVersion = pkgVersion2
+	req2 := NewConfirmationRequest(pkgVersion2, analysisResult2)
+
+	pkgVersion3 := mockPackageVersion("package-3", "1.0.0")
+	analysisResult3 := mockAnalysisResult()
+	analysisResult3.PackageVersion = pkgVersion3
+	req3 := NewConfirmationRequest(pkgVersion3, analysisResult3)
+
+	confirmationChan <- req1
+	confirmationChan <- req2
+	confirmationChan <- req3
+
+	response1 := <-req1.ResponseChan
+	response2 := <-req2.ResponseChan
+	response3 := <-req3.ResponseChan
+
+	assert.True(t, response1)
+	assert.True(t, response2)
+	assert.True(t, response3)
+
+	assert.Equal(t, []string{"package-1", "package-2", "package-3"}, processedPackages)
+
+	close(confirmationChan)
+}
+
+func TestNewConfirmationRequest(t *testing.T) {
+	pkgVersion := mockPackageVersion("test-package", "1.0.0")
+	analysisResult := mockAnalysisResult()
+	analysisResult.PackageVersion = pkgVersion
+
+	req := NewConfirmationRequest(pkgVersion, analysisResult)
+
+	assert.NotNil(t, req)
+	assert.Equal(t, pkgVersion, req.PackageVersion)
+	assert.Equal(t, analysisResult, req.AnalysisResult)
+	assert.NotNil(t, req.ResponseChan)
+	assert.Equal(t, 1, cap(req.ResponseChan), "ResponseChan should have buffer size of 1")
+}

proxy/interceptors/factory.go

@@ -0,0 +1,68 @@
+package interceptors
+
+import (
+	"fmt"
+
+	packagev1 "buf.build/gen/go/safedep/api/protocolbuffers/go/safedep/messages/package/v1"
+	"github.com/safedep/pmg/analyzer"
+	"github.com/safedep/pmg/guard"
+	"github.com/safedep/pmg/proxy"
+)
+
+// InterceptorFactory creates ecosystem-specific interceptors for the proxy
+type InterceptorFactory struct {
+	analyzer         analyzer.PackageVersionAnalyzer
+	cache            AnalysisCache
+	confirmationChan chan *ConfirmationRequest
+	interaction      guard.PackageManagerGuardInteraction
+}
+
+// NewInterceptorFactory creates a new interceptor factory with shared dependencies
+func NewInterceptorFactory(
+	analyzer analyzer.PackageVersionAnalyzer,
+	cache AnalysisCache,
+	confirmationChan chan *ConfirmationRequest,
+	interaction guard.PackageManagerGuardInteraction,
+) *InterceptorFactory {
+	return &InterceptorFactory{
+		analyzer:         analyzer,
+		cache:            cache,
+		confirmationChan: confirmationChan,
+		interaction:      interaction,
+	}
+}
+
+// CreateInterceptor creates an interceptor for the specified ecosystem
+// Returns an error if the ecosystem is not supported for proxy-based interception
+func (f *InterceptorFactory) CreateInterceptor(ecosystem packagev1.Ecosystem) (proxy.Interceptor, error) {
+	switch ecosystem {
+	case packagev1.Ecosystem_ECOSYSTEM_NPM:
+		return NewNpmRegistryInterceptor(
+			f.analyzer,
+			f.cache,
+			f.confirmationChan,
+			f.interaction,
+		), nil
+
+	default:
+		return nil, fmt.Errorf("proxy-based interception not yet supported for ecosystem: %s", ecosystem.String())
+	}
+}
+
+// SupportedEcosystems returns a list of ecosystems that support proxy-based interception
+func SupportedEcosystems() []packagev1.Ecosystem {
+	return []packagev1.Ecosystem{
+		packagev1.Ecosystem_ECOSYSTEM_NPM,
+	}
+}
+
+// IsSupported checks if an ecosystem supports proxy-based interception
+func IsSupported(ecosystem packagev1.Ecosystem) bool {
+	for _, supported := range SupportedEcosystems() {
+		if ecosystem == supported {
+			return true
+		}
+	}
+
+	return false
+}

proxy/interceptors/npm_registry.go

@@ -0,0 +1,91 @@
+package interceptors
+
+import (
+	"strings"
+
+	packagev1 "buf.build/gen/go/safedep/api/protocolbuffers/go/safedep/messages/package/v1"
+	"github.com/safedep/dry/log"
+	"github.com/safedep/pmg/analyzer"
+	"github.com/safedep/pmg/guard"
+	"github.com/safedep/pmg/proxy"
+)
+
+var (
+	npmRegistryDomains = []string{
+		"registry.npmjs.org",
+		"registry.yarnpkg.com",
+	}
+)
+
+// NpmRegistryInterceptor intercepts NPM registry requests and analyzes packages for malware
+// It embeds baseRegistryInterceptor to reuse ecosystem agnostic functionality
+type NpmRegistryInterceptor struct {
+	baseRegistryInterceptor
+}
+
+var _ proxy.Interceptor = (*NpmRegistryInterceptor)(nil)
+
+// NewNpmRegistryInterceptor creates a new NPM registry interceptor
+func NewNpmRegistryInterceptor(
+	analyzer analyzer.PackageVersionAnalyzer,
+	cache AnalysisCache,
+	confirmationChan chan *ConfirmationRequest,
+	interaction guard.PackageManagerGuardInteraction,
+) *NpmRegistryInterceptor {
+	return &NpmRegistryInterceptor{
+		baseRegistryInterceptor: baseRegistryInterceptor{
+			analyzer:         analyzer,
+			cache:            cache,
+			confirmationChan: confirmationChan,
+			interaction:      interaction,
+		},
+	}
+}
+
+// Name returns the interceptor name for logging
+func (i *NpmRegistryInterceptor) Name() string {
+	return "npm-registry-interceptor"
+}
+
+// ShouldIntercept determines if this interceptor should handle the given request
+func (i *NpmRegistryInterceptor) ShouldIntercept(ctx *proxy.RequestContext) bool {
+	for _, domain := range npmRegistryDomains {
+		if ctx.Hostname == domain || strings.HasSuffix(ctx.Hostname, "."+domain) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// HandleRequest processes the request and returns response action
+// We take a fail-open approach here, allowing requests that we can't parse the package information from the URL.
+func (i *NpmRegistryInterceptor) HandleRequest(ctx *proxy.RequestContext) (*proxy.InterceptorResponse, error) {
+	log.Debugf("[%s] Handling NPM registry request: %s", ctx.RequestID, ctx.URL.Path)
+
+	pkgInfo, err := parseNpmRegistryURL(ctx.URL.Path)
+	if err != nil {
+		log.Warnf("[%s] Failed to parse NPM registry URL %s: %v", ctx.RequestID, ctx.URL.Path, err)
+		return &proxy.InterceptorResponse{Action: proxy.ActionAllow}, nil
+	}
+
+	// Only analyze tarball downloads (these have a specific version)
+	// Metadata requests (without version) are allowed through
+	if !pkgInfo.IsTarball {
+		log.Debugf("[%s] Skipping analysis for metadata request: %s", ctx.RequestID, pkgInfo.Name)
+		return &proxy.InterceptorResponse{Action: proxy.ActionAllow}, nil
+	}
+
+	result, err := i.baseRegistryInterceptor.analyzePackage(
+		ctx,
+		packagev1.Ecosystem_ECOSYSTEM_NPM,
+		pkgInfo.Name,
+		pkgInfo.Version,
+	)
+	if err != nil {
+		log.Errorf("[%s] Failed to analyze package %s@%s: %v", ctx.RequestID, pkgInfo.Name, pkgInfo.Version, err)
+		return &proxy.InterceptorResponse{Action: proxy.ActionAllow}, nil
+	}
+
+	return i.baseRegistryInterceptor.handleAnalysisResult(ctx, packagev1.Ecosystem_ECOSYSTEM_NPM, pkgInfo.Name, pkgInfo.Version, result)
+}

proxy/interceptors/npm_url_parser.go

@@ -0,0 +1,205 @@
+package interceptors
+
+import (
+	"fmt"
+	"strings"
+)
+
+// npmPackageInfo represents parsed package information from an NPM registry URL
+type npmPackageInfo struct {
+	Name      string
+	Version   string
+	IsTarball bool
+	IsScoped  bool
+}
+
+// parseNpmRegistryURL parses an NPM registry URL path to extract package information
+//
+// Supported URL patterns:
+// - /package                               -> {Name: "package", Version: ""}
+// - /package/1.0.0                         -> {Name: "package", Version: "1.0.0"}
+// - /@scope/package                        -> {Name: "@scope/package", Version: "", IsScoped: true}
+// - /@scope/package/1.0.0                  -> {Name: "@scope/package", Version: "1.0.0", IsScoped: true}
+// - /package/-/package-1.0.0.tgz          -> {Name: "package", Version: "1.0.0", IsTarball: true}
+// - /@scope/package/-/@scope-package-1.0.0.tgz -> {Name: "@scope/package", Version: "1.0.0", IsTarball: true, IsScoped: true}
+func parseNpmRegistryURL(urlPath string) (*npmPackageInfo, error) {
+	// Remove leading and trailing slashes
+	urlPath = strings.Trim(urlPath, "/")
+
+	if urlPath == "" {
+		return nil, fmt.Errorf("empty URL path")
+	}
+
+	// Split path into segments
+	segments := strings.Split(urlPath, "/")
+
+	// Check if this is a scoped package (starts with @)
+	isScoped := len(segments) > 0 && strings.HasPrefix(segments[0], "@")
+
+	if isScoped {
+		return parseScopedPackageURL(segments)
+	}
+
+	return parseUnscopedPackageURL(segments)
+}
+
+// parseScopedPackageURL parses a scoped package URL
+// Patterns:
+// - [@scope, package]                    -> @scope/package
+// - [@scope, package, version]           -> @scope/package@version
+// - [@scope, package, -, tarball.tgz]    -> @scope/package@version (extract from tarball)
+func parseScopedPackageURL(segments []string) (*npmPackageInfo, error) {
+	if len(segments) < 2 {
+		return nil, fmt.Errorf("invalid scoped package URL: not enough segments")
+	}
+
+	scope := segments[0]
+	packageName := segments[1]
+	fullName := scope + "/" + packageName
+
+	info := &npmPackageInfo{
+		Name:     fullName,
+		IsScoped: true,
+	}
+
+	// Just the scoped package name: /@scope/package
+	if len(segments) == 2 {
+		return info, nil
+	}
+
+	// Check if this is a tarball download: /@scope/package/-/tarball.tgz
+	if len(segments) == 4 && segments[2] == "-" {
+		tarballName := segments[3]
+
+		// Extract version from tarball filename
+		// Format: @scope-package-1.0.0.tgz
+		version, err := extractVersionFromScopedTarball(scope, packageName, tarballName)
+		if err != nil {
+			return nil, fmt.Errorf("failed to extract version from tarball %s: %w", tarballName, err)
+		}
+
+		info.Version = version
+		info.IsTarball = true
+		return info, nil
+	}
+
+	// Version metadata: /@scope/package/1.0.0
+	if len(segments) == 3 {
+		info.Version = segments[2]
+		return info, nil
+	}
+
+	return nil, fmt.Errorf("invalid scoped package URL format: unexpected number of segments %d", len(segments))
+}
+
+// parseUnscopedPackageURL parses an unscoped package URL
+// Patterns:
+// - [package]                -> package
+// - [package, version]       -> package@version
+// - [package, -, tarball.tgz] -> package@version (extract from tarball)
+func parseUnscopedPackageURL(segments []string) (*npmPackageInfo, error) {
+	if len(segments) == 0 {
+		return nil, fmt.Errorf("invalid unscoped package URL: no segments")
+	}
+
+	packageName := segments[0]
+
+	info := &npmPackageInfo{
+		Name:     packageName,
+		IsScoped: false,
+	}
+
+	// Just the package name: /package
+	if len(segments) == 1 {
+		return info, nil
+	}
+
+	// Check if this is a tarball download: /package/-/package-1.0.0.tgz
+	if len(segments) == 3 && segments[1] == "-" {
+		tarballName := segments[2]
+
+		// Extract version from tarball filename
+		// Format: package-1.0.0.tgz
+		version, err := extractVersionFromTarball(packageName, tarballName)
+		if err != nil {
+			return nil, fmt.Errorf("failed to extract version from tarball %s: %w", tarballName, err)
+		}
+
+		info.Version = version
+		info.IsTarball = true
+		return info, nil
+	}
+
+	// Version metadata: /package/1.0.0
+	if len(segments) == 2 {
+		info.Version = segments[1]
+		return info, nil
+	}
+
+	return nil, fmt.Errorf("invalid unscoped package URL format: unexpected number of segments %d", len(segments))
+}
+
+// extractVersionFromTarball extracts version from a tarball filename
+// Expected format: package-name-1.0.0.tgz
+func extractVersionFromTarball(packageName, tarballName string) (string, error) {
+	// Expected format: {packageName}-{version}.tgz
+	expectedPrefix := packageName + "-"
+
+	if !strings.HasPrefix(tarballName, expectedPrefix) {
+		return "", fmt.Errorf("tarball name %s does not match package name %s", tarballName, packageName)
+	}
+
+	if !strings.HasSuffix(tarballName, ".tgz") {
+		return "", fmt.Errorf("tarball name %s does not end with .tgz", tarballName)
+	}
+
+	// Extract version by removing prefix and suffix
+	version := strings.TrimPrefix(tarballName, expectedPrefix)
+	version = strings.TrimSuffix(version, ".tgz")
+
+	if version == "" {
+		return "", fmt.Errorf("could not extract version from tarball %s", tarballName)
+	}
+
+	return version, nil
+}
+
+// extractVersionFromScopedTarball extracts version from a scoped package tarball filename
+// NPM registry uses two different formats for scoped package tarballs:
+// Format 1: {scope}-{package}-{version}.tgz (e.g., types-node-18.0.0.tgz for @types/node)
+// Format 2: {package}-{version}.tgz (e.g., studio-core-licensed-0.0.0.tgz for @prisma/studio-core-licensed)
+func extractVersionFromScopedTarball(scope, packageName, tarballName string) (string, error) {
+	if !strings.HasSuffix(tarballName, ".tgz") {
+		return "", fmt.Errorf("tarball name %s does not end with .tgz", tarballName)
+	}
+
+	scopeWithoutAt := strings.TrimPrefix(scope, "@")
+
+	// Try Format 1: {scope}-{packageName}-{version}.tgz
+	expectedPrefixWithScope := scopeWithoutAt + "-" + packageName + "-"
+	if strings.HasPrefix(tarballName, expectedPrefixWithScope) {
+		version := strings.TrimPrefix(tarballName, expectedPrefixWithScope)
+		version = strings.TrimSuffix(version, ".tgz")
+
+		if version == "" {
+			return "", fmt.Errorf("could not extract version from tarball %s", tarballName)
+		}
+
+		return version, nil
+	}
+
+	// Try Format 2: {packageName}-{version}.tgz
+	expectedPrefixWithoutScope := packageName + "-"
+	if strings.HasPrefix(tarballName, expectedPrefixWithoutScope) {
+		version := strings.TrimPrefix(tarballName, expectedPrefixWithoutScope)
+		version = strings.TrimSuffix(version, ".tgz")
+
+		if version == "" {
+			return "", fmt.Errorf("could not extract version from tarball %s", tarballName)
+		}
+
+		return version, nil
+	}
+
+	return "", fmt.Errorf("tarball name %s does not match expected formats for scoped package %s/%s", tarballName, scope, packageName)
+}

proxy/interceptors/npm_url_parser_test.go

@@ -0,0 +1,282 @@
+package interceptors
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseNpmRegistryURL(t *testing.T) {
+	tests := []struct {
+		name          string
+		urlPath       string
+		wantName      string
+		wantVersion   string
+		wantIsTarball bool
+		wantIsScoped  bool
+		wantErr       bool
+	}{
+		// Unscoped packages - metadata requests
+		{
+			name:          "unscoped package without version",
+			urlPath:       "/lodash",
+			wantName:      "lodash",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+		{
+			name:          "unscoped package with version",
+			urlPath:       "/lodash/4.17.21",
+			wantName:      "lodash",
+			wantVersion:   "4.17.21",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+		{
+			name:          "unscoped package with leading slash",
+			urlPath:       "/express",
+			wantName:      "express",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+		{
+			name:          "unscoped package with trailing slash",
+			urlPath:       "/react/",
+			wantName:      "react",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+
+		// Unscoped packages - tarball downloads
+		{
+			name:          "unscoped package tarball",
+			urlPath:       "/lodash/-/lodash-4.17.21.tgz",
+			wantName:      "lodash",
+			wantVersion:   "4.17.21",
+			wantIsTarball: true,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+		{
+			name:          "unscoped package tarball with prerelease",
+			urlPath:       "/react/-/react-18.0.0-rc.1.tgz",
+			wantName:      "react",
+			wantVersion:   "18.0.0-rc.1",
+			wantIsTarball: true,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+		{
+			name:          "unscoped package tarball with build metadata",
+			urlPath:       "/vue/-/vue-3.2.0+build123.tgz",
+			wantName:      "vue",
+			wantVersion:   "3.2.0+build123",
+			wantIsTarball: true,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+
+		// Scoped packages - metadata requests
+		{
+			name:          "scoped package without version",
+			urlPath:       "/@types/node",
+			wantName:      "@types/node",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  true,
+			wantErr:       false,
+		},
+		{
+			name:          "scoped package with version",
+			urlPath:       "/@types/node/18.0.0",
+			wantName:      "@types/node",
+			wantVersion:   "18.0.0",
+			wantIsTarball: false,
+			wantIsScoped:  true,
+			wantErr:       false,
+		},
+		{
+			name:          "scoped package with complex scope",
+			urlPath:       "/@babel/core",
+			wantName:      "@babel/core",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  true,
+			wantErr:       false,
+		},
+
+		// Scoped packages - tarball downloads
+		{
+			name:          "scoped package tarball",
+			urlPath:       "/@types/node/-/types-node-18.0.0.tgz",
+			wantName:      "@types/node",
+			wantVersion:   "18.0.0",
+			wantIsTarball: true,
+			wantIsScoped:  true,
+			wantErr:       false,
+		},
+		{
+			name:          "scoped package tarball with prerelease",
+			urlPath:       "/@babel/core/-/babel-core-7.20.0-beta.1.tgz",
+			wantName:      "@babel/core",
+			wantVersion:   "7.20.0-beta.1",
+			wantIsTarball: true,
+			wantIsScoped:  true,
+			wantErr:       false,
+		},
+		{
+			name:          "scoped package with hyphenated name",
+			urlPath:       "/@angular/common-http/-/angular-common-http-15.0.0.tgz",
+			wantName:      "@angular/common-http",
+			wantVersion:   "15.0.0",
+			wantIsTarball: true,
+			wantIsScoped:  true,
+			wantErr:       false,
+		},
+		{
+			name:          "scoped package tarball without scope prefix (Format 2)",
+			urlPath:       "/@prisma/studio-core-licensed/-/studio-core-licensed-0.0.0-dev.202601011229.tgz",
+			wantName:      "@prisma/studio-core-licensed",
+			wantVersion:   "0.0.0-dev.202601011229",
+			wantIsTarball: true,
+			wantIsScoped:  true,
+			wantErr:       false,
+		},
+		{
+			name:          "scoped package tarball with scope prefix (Format 1)",
+			urlPath:       "/@types/node/-/types-node-20.0.0.tgz",
+			wantName:      "@types/node",
+			wantVersion:   "20.0.0",
+			wantIsTarball: true,
+			wantIsScoped:  true,
+			wantErr:       false,
+		},
+
+		// Error cases
+		{
+			name:          "empty URL path",
+			urlPath:       "",
+			wantName:      "",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       true,
+		},
+		{
+			name:          "just slash",
+			urlPath:       "/",
+			wantName:      "",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       true,
+		},
+		{
+			name:          "scoped package missing package name",
+			urlPath:       "/@types",
+			wantName:      "",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       true,
+		},
+		{
+			name:          "unscoped package with too many segments",
+			urlPath:       "/lodash/4.17.21/extra/segment",
+			wantName:      "",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       true,
+		},
+		{
+			name:          "scoped package with too many segments",
+			urlPath:       "/@types/node/18.0.0/extra/segment",
+			wantName:      "",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       true,
+		},
+		{
+			name:          "malformed tarball - wrong prefix",
+			urlPath:       "/lodash/-/react-4.17.21.tgz",
+			wantName:      "",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       true,
+		},
+		{
+			name:          "malformed tarball - no .tgz extension",
+			urlPath:       "/lodash/-/lodash-4.17.21.tar.gz",
+			wantName:      "",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       true,
+		},
+		{
+			name:          "scoped tarball with wrong scope in filename",
+			urlPath:       "/@types/node/-/babel-node-18.0.0.tgz",
+			wantName:      "",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       true,
+		},
+
+		// Edge cases
+		{
+			name:          "package name with numbers",
+			urlPath:       "/vue3",
+			wantName:      "vue3",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+		{
+			name:          "package name with hyphens",
+			urlPath:       "/express-validator",
+			wantName:      "express-validator",
+			wantVersion:   "",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+		{
+			name:          "version with v prefix (uncommon but valid)",
+			urlPath:       "/lodash/v4.17.21",
+			wantName:      "lodash",
+			wantVersion:   "v4.17.21",
+			wantIsTarball: false,
+			wantIsScoped:  false,
+			wantErr:       false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := parseNpmRegistryURL(tt.urlPath)
+
+			if tt.wantErr {
+				assert.Error(t, err)
+				return
+			}
+
+			assert.NoError(t, err)
+			assert.Equal(t, tt.wantName, got.Name)
+			assert.Equal(t, tt.wantVersion, got.Version)
+			assert.Equal(t, tt.wantIsTarball, got.IsTarball)
+			assert.Equal(t, tt.wantIsScoped, got.IsScoped)
+		})
+	}
+}