diff --git a/core/internal/common/BUILD.bazel b/core/internal/common/BUILD.bazel
new file mode 100644
index 0000000..4312b88
--- /dev/null
+++ b/core/internal/common/BUILD.bazel
@@ -0,0 +1,20 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "grpc.go",
+        "service.go",
+        "setup.go",
+        "storage.go",
+        "util.go",
+    ],
+    importpath = "git.monogon.dev/source/nexantic.git/core/internal/common",
+    visibility = ["//core:__subpackages__"],
+    deps = [
+        "//core/api/api:go_default_library",
+        "//core/api/common:go_default_library",
+        "@org_golang_google_grpc//:go_default_library",
+        "@org_uber_go_zap//:go_default_library",
+    ],
+)
diff --git a/core/internal/common/grpc.go b/core/internal/common/grpc.go
new file mode 100644
index 0000000..5512a5c
--- /dev/null
+++ b/core/internal/common/grpc.go
@@ -0,0 +1,52 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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 common
+
+import (
+	"git.monogon.dev/source/nexantic.git/core/generated/api"
+
+	"google.golang.org/grpc"
+)
+
+type (
+	SmalltownClient struct {
+		conn *grpc.ClientConn
+
+		Cluster api.ClusterManagementClient
+		Setup   api.SetupServiceClient
+	}
+)
+
+func NewSmalltownAPIClient(address string) (*SmalltownClient, error) {
+	s := &SmalltownClient{}
+
+	conn, err := grpc.Dial(address, grpc.WithInsecure())
+	if err != nil {
+		return nil, err
+	}
+	s.conn = conn
+
+	// Setup all client connections
+	s.Cluster = api.NewClusterManagementClient(conn)
+	s.Setup = api.NewSetupServiceClient(conn)
+
+	return s, nil
+}
+
+func (s *SmalltownClient) Close() error {
+	return s.conn.Close()
+}
diff --git a/core/internal/common/service.go b/core/internal/common/service.go
new file mode 100644
index 0000000..3bdc1f9
--- /dev/null
+++ b/core/internal/common/service.go
@@ -0,0 +1,104 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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 common
+
+import (
+	"errors"
+	"go.uber.org/zap"
+	"sync"
+)
+
+var (
+	ErrAlreadyRunning = errors.New("service is already running")
+	ErrNotRunning     = errors.New("service is not running")
+)
+
+type (
+	// Service represents a subsystem of an application that can be used with a BaseService.
+	Service interface {
+		OnStart() error
+		OnStop() error
+	}
+
+	// BaseService implements utility functionality around a service.
+	BaseService struct {
+		impl Service
+		name string
+
+		Logger *zap.Logger
+
+		mutex   sync.Mutex
+		running bool
+	}
+)
+
+func NewBaseService(name string, logger *zap.Logger, impl Service) *BaseService {
+	return &BaseService{
+		Logger: logger,
+		name:   name,
+		impl:   impl,
+	}
+}
+
+// Start starts the service. This is an atomic operation and should not be called on an already running service.
+func (b *BaseService) Start() error {
+	b.mutex.Lock()
+	defer b.mutex.Unlock()
+
+	if b.running {
+		return ErrAlreadyRunning
+	}
+
+	err := b.impl.OnStart()
+	if err != nil {
+		b.Logger.Error("Failed to start service", zap.String("service", b.name), zap.Error(err))
+		return err
+	}
+
+	b.running = true
+	b.Logger.Info("Started service", zap.String("service", b.name))
+	return nil
+}
+
+// Stop stops the service. THis is an atomic operation and should only be called on a running service.
+func (b *BaseService) Stop() error {
+	b.mutex.Lock()
+	defer b.mutex.Unlock()
+
+	if !b.running {
+		return ErrNotRunning
+	}
+
+	err := b.impl.OnStart()
+	if err != nil {
+		b.Logger.Error("Failed to stop service", zap.String("service", b.name), zap.Error(err))
+
+		return err
+	}
+
+	b.running = false
+	b.Logger.Info("Stopped service", zap.String("service", b.name))
+	return nil
+}
+
+// IsRunning returns whether the service is currently running.
+func (b *BaseService) IsRunning() bool {
+	b.mutex.Lock()
+	defer b.mutex.Unlock()
+
+	return b.running
+}
diff --git a/core/internal/common/setup.go b/core/internal/common/setup.go
new file mode 100644
index 0000000..fd70d0a
--- /dev/null
+++ b/core/internal/common/setup.go
@@ -0,0 +1,35 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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 common
+
+type (
+	SetupService interface {
+		CurrentState() SmalltownState
+		GetJoinClusterToken() string
+		SetupNewCluster(name string, externalHost string) error
+		EnterJoinClusterMode() error
+		JoinCluster(name string, clusterString string, externalHost string) error
+	}
+
+	SmalltownState string
+)
+
+const (
+	StateSetupMode       SmalltownState = "setup"
+	StateClusterJoinMode SmalltownState = "join"
+	StateConfigured      SmalltownState = "configured"
+)
diff --git a/core/internal/common/storage.go b/core/internal/common/storage.go
new file mode 100644
index 0000000..caaa155
--- /dev/null
+++ b/core/internal/common/storage.go
@@ -0,0 +1,37 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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 common
+
+import "errors"
+
+type DataPlace uint32
+
+const (
+	PlaceESP  DataPlace = 0
+	PlaceData           = 1
+)
+
+var (
+	// ErrNotInitialized will be returned when trying to access a place that's not yet initialized
+	ErrNotInitialized = errors.New("This place is not initialized")
+	// ErrUnknownPlace will be returned when trying to access a place that's not known
+	ErrUnknownPlace = errors.New("This place is not known")
+)
+
+type StorageManager interface {
+	GetPathInPlace(place DataPlace, path string) (string, error)
+}
diff --git a/core/internal/common/util.go b/core/internal/common/util.go
new file mode 100644
index 0000000..fc8a72b
--- /dev/null
+++ b/core/internal/common/util.go
@@ -0,0 +1,33 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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 common
+
+import "git.monogon.dev/source/nexantic.git/core/generated/common"
+
+func MapToKVs(input map[string]string) []*common.KV {
+	kvs := make([]*common.KV, len(input))
+
+	i := 0
+	for key, item := range input {
+		kvs[i] = &common.KV{
+			Key:   key,
+			Value: []byte(item),
+		}
+	}
+
+	return kvs
+}