diff --git a/ipn/handle.go b/ipn/handle.go
deleted file mode 100644
index 225f1b6ed..000000000
--- a/ipn/handle.go
+++ /dev/null
@@ -1,176 +0,0 @@
-// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package ipn
-
-import (
-	"net/netip"
-	"sync"
-	"time"
-
-	"tailscale.com/tailcfg"
-	"tailscale.com/types/logger"
-	"tailscale.com/types/netmap"
-)
-
-type Handle struct {
-	b    Backend
-	logf logger.Logf
-
-	// Mutex protects everything below
-	mu                sync.Mutex
-	xnotify           func(Notify)
-	frontendLogID     string
-	netmapCache       *netmap.NetworkMap
-	engineStatusCache EngineStatus
-	stateCache        State
-	prefsCache        *Prefs
-}
-
-func NewHandle(b Backend, logf logger.Logf, notify func(Notify), opts Options) (*Handle, error) {
-	h := &Handle{
-		b:    b,
-		logf: logf,
-	}
-
-	h.SetNotifyCallback(notify)
-	err := h.Start(opts)
-	if err != nil {
-		return nil, err
-	}
-
-	return h, nil
-}
-
-func (h *Handle) SetNotifyCallback(notify func(Notify)) {
-	h.mu.Lock()
-	h.xnotify = notify
-	h.mu.Unlock()
-
-	h.b.SetNotifyCallback(h.notify)
-}
-
-func (h *Handle) Start(opts Options) error {
-	h.mu.Lock()
-	h.frontendLogID = opts.FrontendLogID
-	h.netmapCache = nil
-	h.engineStatusCache = EngineStatus{}
-	h.stateCache = NoState
-	if opts.Prefs != nil {
-		h.prefsCache = opts.Prefs.Clone()
-	}
-	h.mu.Unlock()
-	return h.b.Start(opts)
-}
-
-func (h *Handle) Reset() {
-	st := NoState
-	h.notify(Notify{State: &st})
-}
-
-func (h *Handle) notify(n Notify) {
-	h.mu.Lock()
-	if n.BackendLogID != nil {
-		h.logf("Handle: logs: be:%v fe:%v",
-			*n.BackendLogID, h.frontendLogID)
-	}
-	if n.State != nil {
-		h.stateCache = *n.State
-	}
-	if n.Prefs != nil {
-		h.prefsCache = n.Prefs.Clone()
-	}
-	if n.NetMap != nil {
-		h.netmapCache = n.NetMap
-	}
-	if n.Engine != nil {
-		h.engineStatusCache = *n.Engine
-	}
-	h.mu.Unlock()
-
-	if h.xnotify != nil {
-		// Forward onward to our parent's notifier
-		h.xnotify(n)
-	}
-}
-
-func (h *Handle) Prefs() *Prefs {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	return h.prefsCache.Clone()
-}
-
-func (h *Handle) UpdatePrefs(updateFn func(p *Prefs)) {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	new := h.prefsCache.Clone()
-	updateFn(new)
-	h.prefsCache = new
-	h.b.SetPrefs(new)
-}
-
-func (h *Handle) State() State {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	return h.stateCache
-}
-
-func (h *Handle) EngineStatus() EngineStatus {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	return h.engineStatusCache
-}
-
-func (h *Handle) LocalAddrs() []netip.Prefix {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	nm := h.netmapCache
-	if nm != nil {
-		return nm.Addresses
-	}
-	return []netip.Prefix{}
-}
-
-func (h *Handle) NetMap() *netmap.NetworkMap {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	return h.netmapCache
-}
-
-func (h *Handle) Expiry() time.Time {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	nm := h.netmapCache
-	if nm != nil {
-		return nm.Expiry
-	}
-	return time.Time{}
-}
-
-func (h *Handle) AdminPageURL() string {
-	return h.prefsCache.AdminPageURL()
-}
-
-func (h *Handle) StartLoginInteractive() {
-	h.b.StartLoginInteractive()
-}
-
-func (h *Handle) Login(token *tailcfg.Oauth2Token) {
-	h.b.Login(token)
-}
-
-func (h *Handle) Logout() {
-	h.b.Logout()
-}
-
-func (h *Handle) RequestEngineStatus() {
-	h.b.RequestEngineStatus()
-}
diff --git a/ipn/message_test.go b/ipn/message_test.go
index e3b3b7d12..cc95e938a 100644
--- a/ipn/message_test.go
+++ b/ipn/message_test.go
@@ -6,12 +6,8 @@ package ipn
 
 import (
 	"bytes"
-	"context"
-	"encoding/json"
 	"testing"
-	"time"
 
-	"tailscale.com/tailcfg"
 	"tailscale.com/tstest"
 )
 
@@ -61,133 +57,6 @@ func TestReadWrite(t *testing.T) {
 	}
 }
 
-func TestClientServer(t *testing.T) {
-	tstest.PanicOnLog()
-	tstest.ResourceCheck(t)
-
-	b := &FakeBackend{}
-	var bs *BackendServer
-	var bc *BackendClient
-	serverToClientCh := make(chan []byte, 16)
-	defer close(serverToClientCh)
-	go func() {
-		for b := range serverToClientCh {
-			bc.GotNotifyMsg(b)
-		}
-	}()
-	serverToClient := func(n Notify) {
-		b, err := json.Marshal(n)
-		if err != nil {
-			panic(err.Error())
-		}
-		serverToClientCh <- append([]byte{}, b...)
-	}
-	clientToServer := func(b []byte) {
-		bs.GotCommandMsg(context.TODO(), b)
-	}
-	slogf := func(fmt string, args ...any) {
-		t.Logf("s: "+fmt, args...)
-	}
-	clogf := func(fmt string, args ...any) {
-		t.Logf("c: "+fmt, args...)
-	}
-	bs = NewBackendServer(slogf, b, serverToClient)
-	// Verify that this doesn't break bs's callback:
-	NewBackendServer(slogf, b, nil)
-	bc = NewBackendClient(clogf, clientToServer)
-
-	ch := make(chan Notify, 256)
-	notify := func(n Notify) { ch <- n }
-	h, err := NewHandle(bc, clogf, notify, Options{
-		Prefs: &Prefs{
-			ControlURL: "http://example.com/fake",
-		},
-	})
-	if err != nil {
-		t.Fatalf("NewHandle error: %v\n", err)
-	}
-
-	notes := Notify{}
-	nn := []Notify{}
-	processNote := func(n Notify) {
-		nn = append(nn, n)
-		if n.State != nil {
-			t.Logf("state change: %v", *n.State)
-			notes.State = n.State
-		}
-		if n.Prefs != nil {
-			notes.Prefs = n.Prefs
-		}
-		if n.NetMap != nil {
-			notes.NetMap = n.NetMap
-		}
-		if n.Engine != nil {
-			notes.Engine = n.Engine
-		}
-		if n.BrowseToURL != nil {
-			notes.BrowseToURL = n.BrowseToURL
-		}
-	}
-	notesState := func() State {
-		if notes.State != nil {
-			return *notes.State
-		}
-		return NoState
-	}
-
-	flushUntil := func(wantFlush State) {
-		t.Helper()
-		timer := time.NewTimer(1 * time.Second)
-	loop:
-		for {
-			select {
-			case n := <-ch:
-				processNote(n)
-				if notesState() == wantFlush {
-					break loop
-				}
-			case <-timer.C:
-				t.Fatalf("timeout waiting for state %v, got %v", wantFlush, notes.State)
-			}
-		}
-		timer.Stop()
-	loop2:
-		for {
-			select {
-			case n := <-ch:
-				processNote(n)
-			default:
-				break loop2
-			}
-		}
-		if got, want := h.State(), notesState(); got != want {
-			t.Errorf("h.State()=%v, notes.State=%v (on flush until %v)\n", got, want, wantFlush)
-		}
-	}
-
-	flushUntil(NeedsLogin)
-
-	h.StartLoginInteractive()
-	flushUntil(Running)
-	if notes.NetMap == nil && h.NetMap() != nil {
-		t.Errorf("notes.NetMap == nil while h.NetMap != nil\nnotes:\n%v", nn)
-	}
-
-	h.UpdatePrefs(func(p *Prefs) {
-		p.WantRunning = false
-	})
-	flushUntil(Stopped)
-
-	h.Logout()
-	flushUntil(NeedsLogin)
-
-	h.Login(&tailcfg.Oauth2Token{
-		AccessToken: "google_id_token",
-		TokenType:   GoogleIDTokenType,
-	})
-	flushUntil(Running)
-}
-
 func TestNilBackend(t *testing.T) {
 	var called *Notify
 	bs := NewBackendServer(t.Logf, nil, func(n Notify) {