diff --git a/federationapi/federationapi_keys_test.go b/federationapi/federationapi_keys_test.go
index 4774c8820..31e9a4c73 100644
--- a/federationapi/federationapi_keys_test.go
+++ b/federationapi/federationapi_keys_test.go
@@ -102,7 +102,7 @@ func TestMain(m *testing.M) {
 		)
 
 		// Finally, build the server key APIs.
-		sbase := base.NewBaseDendrite(cfg, "Monolith", base.NoCacheMetrics)
+		sbase := base.NewBaseDendrite(cfg, "Monolith", base.DisableMetrics)
 		s.api = NewInternalAPI(sbase, s.fedclient, nil, s.cache, nil, true)
 	}
 
diff --git a/setup/base/base.go b/setup/base/base.go
index ef449cc35..da122bf8f 100644
--- a/setup/base/base.go
+++ b/setup/base/base.go
@@ -84,6 +84,7 @@ type BaseDendrite struct {
 	DNSCache               *gomatrixserverlib.DNSCache
 	Database               *sql.DB
 	DatabaseWriter         sqlutil.Writer
+	EnableMetrics          bool
 }
 
 const NoListener = ""
@@ -94,7 +95,7 @@ const HTTPClientTimeout = time.Second * 30
 type BaseDendriteOptions int
 
 const (
-	NoCacheMetrics BaseDendriteOptions = iota
+	DisableMetrics BaseDendriteOptions = iota
 	UseHTTPAPIs
 	PolylithMode
 )
@@ -105,12 +106,12 @@ const (
 func NewBaseDendrite(cfg *config.Dendrite, componentName string, options ...BaseDendriteOptions) *BaseDendrite {
 	platformSanityChecks()
 	useHTTPAPIs := false
-	cacheMetrics := true
+	enableMetrics := true
 	isMonolith := true
 	for _, opt := range options {
 		switch opt {
-		case NoCacheMetrics:
-			cacheMetrics = false
+		case DisableMetrics:
+			enableMetrics = false
 		case UseHTTPAPIs:
 			useHTTPAPIs = true
 		case PolylithMode:
@@ -158,7 +159,7 @@ func NewBaseDendrite(cfg *config.Dendrite, componentName string, options ...Base
 		}
 	}
 
-	cache, err := caching.NewInMemoryLRUCache(cacheMetrics)
+	cache, err := caching.NewInMemoryLRUCache(enableMetrics)
 	if err != nil {
 		logrus.WithError(err).Warnf("Failed to create cache")
 	}
@@ -243,6 +244,7 @@ func NewBaseDendrite(cfg *config.Dendrite, componentName string, options ...Base
 		apiHttpClient:          &apiClient,
 		Database:               db,     // set if monolith with global connection pool only
 		DatabaseWriter:         writer, // set if monolith with global connection pool only
+		EnableMetrics:          enableMetrics,
 	}
 }
 
diff --git a/syncapi/sync/requestpool.go b/syncapi/sync/requestpool.go
index 99d1e40c3..8ab130911 100644
--- a/syncapi/sync/requestpool.go
+++ b/syncapi/sync/requestpool.go
@@ -65,11 +65,13 @@ func NewRequestPool(
 	userAPI userapi.SyncUserAPI, keyAPI keyapi.SyncKeyAPI,
 	rsAPI roomserverAPI.SyncRoomserverAPI,
 	streams *streams.Streams, notifier *notifier.Notifier,
-	producer PresencePublisher,
+	producer PresencePublisher, enableMetrics bool,
 ) *RequestPool {
-	prometheus.MustRegister(
-		activeSyncRequests, waitingSyncRequests,
-	)
+	if enableMetrics {
+		prometheus.MustRegister(
+			activeSyncRequests, waitingSyncRequests,
+		)
+	}
 	rp := &RequestPool{
 		db:       db,
 		cfg:      cfg,
diff --git a/syncapi/syncapi.go b/syncapi/syncapi.go
index 6da8ce6d1..fc43e0bf0 100644
--- a/syncapi/syncapi.go
+++ b/syncapi/syncapi.go
@@ -65,7 +65,7 @@ func AddPublicRoutes(
 		JetStream: js,
 	}
 
-	requestPool := sync.NewRequestPool(syncDB, cfg, userAPI, keyAPI, rsAPI, streams, notifier, federationPresenceProducer)
+	requestPool := sync.NewRequestPool(syncDB, cfg, userAPI, keyAPI, rsAPI, streams, notifier, federationPresenceProducer, base.EnableMetrics)
 
 	userAPIStreamEventProducer := &producers.UserAPIStreamEventProducer{
 		JetStream: js,
diff --git a/syncapi/syncapi_test.go b/syncapi/syncapi_test.go
new file mode 100644
index 000000000..003280aeb
--- /dev/null
+++ b/syncapi/syncapi_test.go
@@ -0,0 +1,95 @@
+package syncapi
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	keyapi "github.com/matrix-org/dendrite/keyserver/api"
+	rsapi "github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/test"
+	userapi "github.com/matrix-org/dendrite/userapi/api"
+)
+
+var (
+	alice            = "@alice:localhost"
+	aliceAccessToken = "ALICE_BEARER_TOKEN"
+)
+
+type syncRoomserverAPI struct {
+	rsapi.RoomserverInternalAPI
+}
+
+type syncUserAPI struct {
+	userapi.UserInternalAPI
+}
+
+func (s *syncUserAPI) QueryAccessToken(ctx context.Context, req *userapi.QueryAccessTokenRequest, res *userapi.QueryAccessTokenResponse) error {
+	if req.AccessToken == aliceAccessToken {
+		res.Device = &userapi.Device{
+			ID:          "ID",
+			UserID:      alice,
+			AccessToken: aliceAccessToken,
+			AccountType: userapi.AccountTypeUser,
+			DisplayName: "Alice",
+		}
+		return nil
+	}
+	res.Err = "unknown user"
+	return nil
+}
+
+func (s *syncUserAPI) PerformLastSeenUpdate(ctx context.Context, req *userapi.PerformLastSeenUpdateRequest, res *userapi.PerformLastSeenUpdateResponse) error {
+	return nil
+}
+
+type syncKeyAPI struct {
+	keyapi.KeyInternalAPI
+}
+
+func TestSyncAPI(t *testing.T) {
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, close := test.CreateBaseDendrite(t, dbType)
+		defer close()
+		AddPublicRoutes(base, &syncUserAPI{}, &syncRoomserverAPI{}, &syncKeyAPI{})
+
+		testCases := []struct {
+			name     string
+			req      *http.Request
+			wantCode int
+		}{
+			{
+				name: "missing access token",
+				req: test.NewRequest(t, "GET", "/_matrix/client/v3/sync", test.WithQueryParams(map[string]string{
+					"timeout": "0",
+				})),
+				wantCode: 401,
+			},
+			{
+				name: "unknown access token",
+				req: test.NewRequest(t, "GET", "/_matrix/client/v3/sync", test.WithQueryParams(map[string]string{
+					"access_token": "foo",
+					"timeout":      "0",
+				})),
+				wantCode: 401,
+			},
+			{
+				name: "valid access token",
+				req: test.NewRequest(t, "GET", "/_matrix/client/v3/sync", test.WithQueryParams(map[string]string{
+					"access_token": aliceAccessToken,
+					"timeout":      "0",
+				})),
+				wantCode: 200,
+			},
+		}
+
+		for _, tc := range testCases {
+			w := httptest.NewRecorder()
+			base.PublicClientAPIMux.ServeHTTP(w, tc.req)
+			if w.Code != tc.wantCode {
+				t.Fatalf("%s: got HTTP %d want %d", tc.name, w.Code, tc.wantCode)
+			}
+		}
+	})
+}
diff --git a/test/base.go b/test/base.go
new file mode 100644
index 000000000..972d86056
--- /dev/null
+++ b/test/base.go
@@ -0,0 +1,70 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package test
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/matrix-org/dendrite/setup/base"
+	"github.com/matrix-org/dendrite/setup/config"
+)
+
+func CreateBaseDendrite(t *testing.T, dbType DBType) (*base.BaseDendrite, func()) {
+	var cfg config.Dendrite
+	cfg.Defaults(false)
+
+	switch dbType {
+	case DBTypePostgres:
+		cfg.Global.Defaults(true)   // autogen a signing key
+		cfg.MediaAPI.Defaults(true) // autogen a media path
+		connStr, close := PrepareDBConnectionString(t, dbType)
+		cfg.Global.DatabaseOptions = config.DatabaseOptions{
+			ConnectionString:       config.DataSource(connStr),
+			MaxOpenConnections:     10,
+			MaxIdleConnections:     2,
+			ConnMaxLifetimeSeconds: 60,
+		}
+		return base.NewBaseDendrite(&cfg, "Test", base.DisableMetrics), close
+	case DBTypeSQLite:
+		cfg.Defaults(true) // sets a sqlite db per component
+		return base.NewBaseDendrite(&cfg, "Test", base.DisableMetrics), func() {
+			// cleanup db files. This risks getting out of sync as we add more database strings :(
+			dbFiles := []config.DataSource{
+				cfg.AppServiceAPI.Database.ConnectionString,
+				cfg.FederationAPI.Database.ConnectionString,
+				cfg.KeyServer.Database.ConnectionString,
+				cfg.MSCs.Database.ConnectionString,
+				cfg.MediaAPI.Database.ConnectionString,
+				cfg.RoomServer.Database.ConnectionString,
+				cfg.SyncAPI.Database.ConnectionString,
+				cfg.UserAPI.AccountDatabase.ConnectionString,
+			}
+			for _, fileURI := range dbFiles {
+				path := strings.TrimPrefix(string(fileURI), "file:")
+				err := os.Remove(path)
+				if err != nil && !errors.Is(err, fs.ErrNotExist) {
+					t.Fatalf("failed to cleanup sqlite db '%s': %s", fileURI, err)
+				}
+			}
+		}
+	default:
+		t.Fatalf("unknown db type: %v", dbType)
+	}
+	return nil, nil
+}
diff --git a/test/http.go b/test/http.go
new file mode 100644
index 000000000..a458a3385
--- /dev/null
+++ b/test/http.go
@@ -0,0 +1,45 @@
+package test
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/url"
+	"testing"
+)
+
+type HTTPRequestOpt func(req *http.Request)
+
+func WithJSONBody(t *testing.T, body interface{}) HTTPRequestOpt {
+	t.Helper()
+	b, err := json.Marshal(body)
+	if err != nil {
+		t.Fatalf("WithJSONBody: %s", err)
+	}
+	return func(req *http.Request) {
+		req.Body = io.NopCloser(bytes.NewBuffer(b))
+	}
+}
+
+func WithQueryParams(qps map[string]string) HTTPRequestOpt {
+	var vals url.Values = map[string][]string{}
+	for k, v := range qps {
+		vals.Set(k, v)
+	}
+	return func(req *http.Request) {
+		req.URL.RawQuery = vals.Encode()
+	}
+}
+
+func NewRequest(t *testing.T, method, path string, opts ...HTTPRequestOpt) *http.Request {
+	t.Helper()
+	req, err := http.NewRequest(method, "http://localhost"+path, nil)
+	if err != nil {
+		t.Fatalf("failed to make new HTTP request %v %v : %v", method, path, err)
+	}
+	for _, o := range opts {
+		o(req)
+	}
+	return req
+}