diff --git a/database/accessor/accessor-json-bytes.go b/database/accessor/accessor-json-bytes.go
index 08330d7..3115bf6 100644
--- a/database/accessor/accessor-json-bytes.go
+++ b/database/accessor/accessor-json-bytes.go
@@ -36,6 +36,10 @@ func (ja *JSONBytesAccessor) Set(key string, value interface{}) error {
 			if result.Type != gjson.True && result.Type != gjson.False {
 				return fmt.Errorf("tried to set field %s (%s) to a %T value", key, result.Type.String(), value)
 			}
+		case []string:
+			if !result.IsArray() {
+				return fmt.Errorf("tried to set field %s (%s) to a %T value", key, result.Type.String(), value)
+			}
 		}
 	}
 
@@ -47,6 +51,15 @@ func (ja *JSONBytesAccessor) Set(key string, value interface{}) error {
 	return nil
 }
 
+// Get returns the value found by the given json key and whether it could be successfully extracted.
+func (ja *JSONBytesAccessor) Get(key string) (value interface{}, ok bool) {
+	result := gjson.GetBytes(*ja.json, key)
+	if !result.Exists() {
+		return nil, false
+	}
+	return result.Value(), true
+}
+
 // GetString returns the string found by the given json key and whether it could be successfully extracted.
 func (ja *JSONBytesAccessor) GetString(key string) (value string, ok bool) {
 	result := gjson.GetBytes(*ja.json, key)
@@ -56,6 +69,24 @@ func (ja *JSONBytesAccessor) GetString(key string) (value string, ok bool) {
 	return result.String(), true
 }
 
+// GetStringArray returns the []string found by the given json key and whether it could be successfully extracted.
+func (ja *JSONBytesAccessor) GetStringArray(key string) (value []string, ok bool) {
+	result := gjson.GetBytes(*ja.json, key)
+	if !result.Exists() && !result.IsArray() {
+		return nil, false
+	}
+	slice := result.Array()
+	new := make([]string, len(slice))
+	for i, res := range slice {
+		if res.Type == gjson.String {
+			new[i] = res.String()
+		} else {
+			return nil, false
+		}
+	}
+	return new, true
+}
+
 // GetInt returns the int found by the given json key and whether it could be successfully extracted.
 func (ja *JSONBytesAccessor) GetInt(key string) (value int64, ok bool) {
 	result := gjson.GetBytes(*ja.json, key)
diff --git a/database/accessor/accessor-json-string.go b/database/accessor/accessor-json-string.go
index 1170418..c5c215d 100644
--- a/database/accessor/accessor-json-string.go
+++ b/database/accessor/accessor-json-string.go
@@ -36,6 +36,10 @@ func (ja *JSONAccessor) Set(key string, value interface{}) error {
 			if result.Type != gjson.True && result.Type != gjson.False {
 				return fmt.Errorf("tried to set field %s (%s) to a %T value", key, result.Type.String(), value)
 			}
+		case []string:
+			if !result.IsArray() {
+				return fmt.Errorf("tried to set field %s (%s) to a %T value", key, result.Type.String(), value)
+			}
 		}
 	}
 
@@ -47,6 +51,15 @@ func (ja *JSONAccessor) Set(key string, value interface{}) error {
 	return nil
 }
 
+// Get returns the value found by the given json key and whether it could be successfully extracted.
+func (ja *JSONAccessor) Get(key string) (value interface{}, ok bool) {
+	result := gjson.Get(*ja.json, key)
+	if !result.Exists() {
+		return nil, false
+	}
+	return result.Value(), true
+}
+
 // GetString returns the string found by the given json key and whether it could be successfully extracted.
 func (ja *JSONAccessor) GetString(key string) (value string, ok bool) {
 	result := gjson.Get(*ja.json, key)
@@ -56,6 +69,24 @@ func (ja *JSONAccessor) GetString(key string) (value string, ok bool) {
 	return result.String(), true
 }
 
+// GetStringArray returns the []string found by the given json key and whether it could be successfully extracted.
+func (ja *JSONAccessor) GetStringArray(key string) (value []string, ok bool) {
+	result := gjson.Get(*ja.json, key)
+	if !result.Exists() && !result.IsArray() {
+		return nil, false
+	}
+	slice := result.Array()
+	new := make([]string, len(slice))
+	for i, res := range slice {
+		if res.Type == gjson.String {
+			new[i] = res.String()
+		} else {
+			return nil, false
+		}
+	}
+	return new, true
+}
+
 // GetInt returns the int found by the given json key and whether it could be successfully extracted.
 func (ja *JSONAccessor) GetInt(key string) (value int64, ok bool) {
 	result := gjson.Get(*ja.json, key)
diff --git a/database/accessor/accessor-struct.go b/database/accessor/accessor-struct.go
index b56c9b7..6f245aa 100644
--- a/database/accessor/accessor-struct.go
+++ b/database/accessor/accessor-struct.go
@@ -86,6 +86,15 @@ func (sa *StructAccessor) Set(key string, value interface{}) error {
 	return nil
 }
 
+// Get returns the value found by the given json key and whether it could be successfully extracted.
+func (sa *StructAccessor) Get(key string) (value interface{}, ok bool) {
+	field := sa.object.FieldByName(key)
+	if !field.IsValid() || !field.CanInterface() {
+		return nil, false
+	}
+	return field.Interface(), true
+}
+
 // GetString returns the string found by the given json key and whether it could be successfully extracted.
 func (sa *StructAccessor) GetString(key string) (value string, ok bool) {
 	field := sa.object.FieldByName(key)
@@ -95,6 +104,20 @@ func (sa *StructAccessor) GetString(key string) (value string, ok bool) {
 	return field.String(), true
 }
 
+// GetStringArray returns the []string found by the given json key and whether it could be successfully extracted.
+func (sa *StructAccessor) GetStringArray(key string) (value []string, ok bool) {
+	field := sa.object.FieldByName(key)
+	if !field.IsValid() || field.Kind() != reflect.Slice || !field.CanInterface() {
+		return nil, false
+	}
+	v := field.Interface()
+	slice, ok := v.([]string)
+	if !ok {
+		return nil, false
+	}
+	return slice, true
+}
+
 // GetInt returns the int found by the given json key and whether it could be successfully extracted.
 func (sa *StructAccessor) GetInt(key string) (value int64, ok bool) {
 	field := sa.object.FieldByName(key)
diff --git a/database/accessor/accessor.go b/database/accessor/accessor.go
index aedad26..9fde0e0 100644
--- a/database/accessor/accessor.go
+++ b/database/accessor/accessor.go
@@ -6,7 +6,9 @@ const (
 
 // Accessor provides an interface to supply the query matcher a method to retrieve values from an object.
 type Accessor interface {
+	Get(key string) (value interface{}, ok bool)
 	GetString(key string) (value string, ok bool)
+	GetStringArray(key string) (value []string, ok bool)
 	GetInt(key string) (value int64, ok bool)
 	GetFloat(key string) (value float64, ok bool)
 	GetBool(key string) (value bool, ok bool)
diff --git a/database/accessor/accessor_test.go b/database/accessor/accessor_test.go
index d2a3a20..aab5137 100644
--- a/database/accessor/accessor_test.go
+++ b/database/accessor/accessor_test.go
@@ -3,10 +3,13 @@ package accessor
 import (
 	"encoding/json"
 	"testing"
+
+	"github.com/Safing/portbase/utils"
 )
 
 type TestStruct struct {
 	S    string
+	A    []string
 	I    int
 	I8   int8
 	I16  int16
@@ -25,6 +28,7 @@ type TestStruct struct {
 var (
 	testStruct = &TestStruct{
 		S:    "banana",
+		A:    []string{"black", "white"},
 		I:    42,
 		I8:   42,
 		I16:  42,
@@ -56,6 +60,19 @@ func testGetString(t *testing.T, acc Accessor, key string, shouldSucceed bool, e
 	}
 }
 
+func testGetStringArray(t *testing.T, acc Accessor, key string, shouldSucceed bool, expectedValue []string) {
+	v, ok := acc.GetStringArray(key)
+	switch {
+	case !ok && shouldSucceed:
+		t.Errorf("%s failed to get []string with key %s", acc.Type(), key)
+	case ok && !shouldSucceed:
+		t.Errorf("%s should have failed to get []string with key %s, it returned %v", acc.Type(), key, v)
+	}
+	if !utils.StringSliceEqual(v, expectedValue) {
+		t.Errorf("%s returned an unexpected value: wanted %v, got %v", acc.Type(), expectedValue, v)
+	}
+}
+
 func testGetInt(t *testing.T, acc Accessor, key string, shouldSucceed bool, expectedValue int64) {
 	v, ok := acc.GetInt(key)
 	switch {
@@ -127,6 +144,7 @@ func TestAccessor(t *testing.T) {
 	// get
 	for _, acc := range accs {
 		testGetString(t, acc, "S", true, "banana")
+		testGetStringArray(t, acc, "A", true, []string{"black", "white"})
 		testGetInt(t, acc, "I", true, 42)
 		testGetInt(t, acc, "I8", true, 42)
 		testGetInt(t, acc, "I16", true, 42)
@@ -145,6 +163,7 @@ func TestAccessor(t *testing.T) {
 	// set
 	for _, acc := range accs {
 		testSet(t, acc, "S", true, "coconut")
+		testSet(t, acc, "A", true, []string{"green", "blue"})
 		testSet(t, acc, "I", true, uint32(44))
 		testSet(t, acc, "I8", true, uint64(44))
 		testSet(t, acc, "I16", true, uint8(44))
@@ -163,6 +182,7 @@ func TestAccessor(t *testing.T) {
 	// get again to check if new values were set
 	for _, acc := range accs {
 		testGetString(t, acc, "S", true, "coconut")
+		testGetStringArray(t, acc, "A", true, []string{"green", "blue"})
 		testGetInt(t, acc, "I", true, 44)
 		testGetInt(t, acc, "I8", true, 44)
 		testGetInt(t, acc, "I16", true, 44)
@@ -185,6 +205,12 @@ func TestAccessor(t *testing.T) {
 		testSet(t, acc, "S", false, 1)
 		testSet(t, acc, "S", false, 1.1)
 
+		testSet(t, acc, "A", false, "1")
+		testSet(t, acc, "A", false, true)
+		testSet(t, acc, "A", false, false)
+		testSet(t, acc, "A", false, 1)
+		testSet(t, acc, "A", false, 1.1)
+
 		testSet(t, acc, "I", false, "1")
 		testSet(t, acc, "I8", false, "1")
 		testSet(t, acc, "I16", false, "1")
@@ -207,6 +233,7 @@ func TestAccessor(t *testing.T) {
 	// get again to check if values werent changed when an error occurred
 	for _, acc := range accs {
 		testGetString(t, acc, "S", true, "coconut")
+		testGetStringArray(t, acc, "A", true, []string{"green", "blue"})
 		testGetInt(t, acc, "I", true, 44)
 		testGetInt(t, acc, "I8", true, 44)
 		testGetInt(t, acc, "I16", true, 44)
@@ -225,6 +252,7 @@ func TestAccessor(t *testing.T) {
 	// test existence
 	for _, acc := range accs {
 		testExists(t, acc, "S", true)
+		testExists(t, acc, "A", true)
 		testExists(t, acc, "I", true)
 		testExists(t, acc, "I8", true)
 		testExists(t, acc, "I16", true)
diff --git a/database/controller.go b/database/controller.go
index 02e8d63..d981fc3 100644
--- a/database/controller.go
+++ b/database/controller.go
@@ -157,6 +157,20 @@ func (c *Controller) Query(q *query.Query, local, internal bool) (*iterator.Iter
 	return it, nil
 }
 
+// PushUpdate pushes a record update to subscribers.
+func (c *Controller) PushUpdate(r record.Record) {
+	if c != nil {
+		for _, sub := range c.subscriptions {
+			if r.Meta().CheckPermission(sub.local, sub.internal) && sub.q.Matches(r) {
+				select {
+				case sub.Feed <- r:
+				default:
+				}
+			}
+		}
+	}
+}
+
 func (c *Controller) readUnlockerAfterQuery(it *iterator.Iterator) {
 	<- it.Done
 	c.readLock.RUnlock()
diff --git a/database/controllers.go b/database/controllers.go
index 5b9d002..38d1591 100644
--- a/database/controllers.go
+++ b/database/controllers.go
@@ -30,7 +30,7 @@ func getController(name string) (*Controller, error) {
 	// get db registration
 	registeredDB, err := getDatabase(name)
 	if err != nil {
-		return nil, fmt.Errorf(`could not start database %s (type %s): %s`, name, registeredDB.StorageType, err)
+		return nil, fmt.Errorf(`could not start database %s: %s`, name, err)
 	}
 
 	// get location
@@ -56,13 +56,13 @@ func getController(name string) (*Controller, error) {
 }
 
 // InjectDatabase injects an already running database into the system.
-func InjectDatabase(name string, storageInt storage.Interface) error {
+func InjectDatabase(name string, storageInt storage.Interface) (*Controller, error) {
 	controllersLock.Lock()
 	defer controllersLock.Unlock()
 
 	_, ok := controllers[name]
 	if ok {
-		return errors.New(`database "%s" already loaded`)
+		return nil, errors.New(`database "%s" already loaded`)
 	}
 
   registryLock.Lock()
@@ -71,17 +71,17 @@ func InjectDatabase(name string, storageInt storage.Interface) error {
   // check if database is registered
   registeredDB, ok := registry[name]
   if !ok {
-    return fmt.Errorf(`database "%s" not registered`, name)
+    return nil, fmt.Errorf(`database "%s" not registered`, name)
   }
   if registeredDB.StorageType != "injected" {
-    return fmt.Errorf(`database not of type "injected"`)
+    return nil, fmt.Errorf(`database not of type "injected"`)
   }
 
   controller, err := newController(storageInt)
   if err != nil {
-    return fmt.Errorf(`could not create controller for database %s: %s`, name, err)
+    return nil, fmt.Errorf(`could not create controller for database %s: %s`, name, err)
   }
 
 	controllers[name] = controller
-	return nil
+	return controller, nil
 }
diff --git a/database/database_test.go b/database/database_test.go
index e997760..9aa5e7d 100644
--- a/database/database_test.go
+++ b/database/database_test.go
@@ -98,8 +98,8 @@ func testDatabase(t *testing.T, storageType string) {
 	for _ = range it.Next {
 		cnt++
 	}
-	if it.Error != nil {
-		t.Fatal(it.Error)
+	if it.Err != nil {
+		t.Fatal(it.Err)
 	}
 	if cnt != 2 {
 		t.Fatal("expected two records")
diff --git a/database/iterator/iterator.go b/database/iterator/iterator.go
index 7a1dff4..70451ea 100644
--- a/database/iterator/iterator.go
+++ b/database/iterator/iterator.go
@@ -6,9 +6,9 @@ import (
 
 // Iterator defines the iterator structure.
 type Iterator struct {
-	Next  chan record.Record
-	Done  chan struct{}
-	Error error
+	Next chan record.Record
+	Done chan struct{}
+	Err  error
 }
 
 // New creates a new Iterator.
@@ -18,3 +18,9 @@ func New() *Iterator {
 		Done: make(chan struct{}),
 	}
 }
+
+func (it *Iterator) Finish(err error) {
+	close(it.Next)
+	close(it.Done)
+	it.Err = err
+}
diff --git a/database/location.go b/database/location.go
index 0c095b6..80250cc 100644
--- a/database/location.go
+++ b/database/location.go
@@ -39,6 +39,11 @@ func ensureDirectory(dirPath string) error {
 	return nil
 }
 
+// GetDatabaseRoot returns the root directory of the database.
+func GetDatabaseRoot() string {
+	return rootDir
+}
+
 // getLocation returns the storage location for the given name and type.
 func getLocation(name, storageType string) (string, error) {
 	location := path.Join(rootDir, databasesSubDir, name, storageType)
diff --git a/database/maintenance.go b/database/maintenance.go
index d1399bd..05d8182 100644
--- a/database/maintenance.go
+++ b/database/maintenance.go
@@ -64,7 +64,7 @@ func MaintainRecordStates() error {
         toExpire = append(toExpire, r)
       }
     }
-    if it.Error != nil {
+    if it.Err != nil {
       return err
     }
 
diff --git a/database/record/wrapper.go b/database/record/wrapper.go
index 63bdb66..03c46bc 100644
--- a/database/record/wrapper.go
+++ b/database/record/wrapper.go
@@ -42,10 +42,11 @@ func NewRawWrapper(database, key string, data []byte) (*Wrapper, error) {
 		return nil, fmt.Errorf("could not unmarshal meta section: %s", err)
 	}
 
-	format, _, err := varint.Unpack8(data[offset:])
+	format, n, err := varint.Unpack8(data[offset:])
 	if err != nil {
 		return nil, fmt.Errorf("could not get dsd format: %s", err)
 	}
+	offset += n
 
 	return &Wrapper{
 		Base{
@@ -60,12 +61,7 @@ func NewRawWrapper(database, key string, data []byte) (*Wrapper, error) {
 }
 
 // NewWrapper returns a new record wrapper for the given data.
-func NewWrapper(key string, meta *Meta, data []byte) (*Wrapper, error) {
-	format, _, err := varint.Unpack8(data)
-	if err != nil {
-		return nil, fmt.Errorf("could not get dsd format: %s", err)
-	}
-
+func NewWrapper(key string, meta *Meta, format uint8, data []byte) (*Wrapper, error) {
 	dbName, dbKey := ParseKey(key)
 
 	return &Wrapper{
@@ -81,7 +77,7 @@ func NewWrapper(key string, meta *Meta, data []byte) (*Wrapper, error) {
 }
 
 // Marshal marshals the object, without the database key or metadata
-func (w *Wrapper) Marshal(r Record, storageType uint8) ([]byte, error) {
+func (w *Wrapper) Marshal(r Record, format uint8) ([]byte, error) {
 	if w.Meta() == nil {
 		return nil, errors.New("missing meta")
 	}
@@ -90,10 +86,15 @@ func (w *Wrapper) Marshal(r Record, storageType uint8) ([]byte, error) {
 		return nil, nil
 	}
 
-	if storageType != dsd.AUTO && storageType != w.Format {
+	if format != dsd.AUTO && format != w.Format {
 		return nil, errors.New("could not dump model, wrapped object format mismatch")
 	}
-	return w.Data, nil
+
+	data := make([]byte, len(w.Data)+1)
+	data[0] = w.Format
+	copy(data[1:], w.Data)
+
+	return data, nil
 }
 
 // MarshalRecord packs the object, including metadata, into a byte array for saving in a database.
@@ -146,7 +147,7 @@ func Unwrap(wrapped, new Record) error {
 		return fmt.Errorf("cannot unwrap %T", wrapped)
 	}
 
-	_, err := dsd.Load(wrapper.Data, new)
+	_, err := dsd.LoadAsFormat(wrapper.Data, wrapper.Format, new)
 	if err != nil {
 		return fmt.Errorf("failed to unwrap %T: %s", new, err)
 	}
@@ -159,9 +160,8 @@ func Unwrap(wrapped, new Record) error {
 
 // GetAccessor returns an accessor for this record, if available.
 func (w *Wrapper) GetAccessor(self Record) accessor.Accessor {
-	if len(w.Data) > 1 && w.Data[0] == JSON {
-		jsonData := w.Data[1:]
-		return accessor.NewJSONBytesAccessor(&jsonData)
+	if w.Format == JSON && len(w.Data) > 0 {
+		return accessor.NewJSONBytesAccessor(&w.Data)
 	}
 	return nil
 }
diff --git a/database/record/wrapper_test.go b/database/record/wrapper_test.go
index e2988f0..0e14156 100644
--- a/database/record/wrapper_test.go
+++ b/database/record/wrapper_test.go
@@ -16,10 +16,11 @@ func TestWrapper(t *testing.T) {
 	_ = m
 
 	// create test data
-	testData := []byte(`J{"a": "b"}`)
+	testData := []byte(`{"a": "b"}`)
+	encodedTestData := []byte(`J{"a": "b"}`)
 
 	// test wrapper
-	wrapper, err := NewWrapper("test:a", &Meta{}, testData)
+	wrapper, err := NewWrapper("test:a", &Meta{}, JSON, testData)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -34,7 +35,7 @@ func TestWrapper(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if !bytes.Equal(testData, encoded) {
+	if !bytes.Equal(encodedTestData, encoded) {
 		t.Error("marshal mismatch")
 	}
 
diff --git a/database/registry.go b/database/registry.go
index 1322854..7195bc9 100644
--- a/database/registry.go
+++ b/database/registry.go
@@ -116,7 +116,7 @@ func loadRegistry() error {
 
 	// parse
 	new := make(map[string]*Database)
-	err = json.Unmarshal(data, new)
+	err = json.Unmarshal(data, &new)
 	if err != nil {
 		return err
 	}
diff --git a/database/storage/badger/badger.go b/database/storage/badger/badger.go
index 0ff6abe..3df5a37 100644
--- a/database/storage/badger/badger.go
+++ b/database/storage/badger/badger.go
@@ -163,7 +163,7 @@ func (b *Badger) queryExecutor(queryIter *iterator.Iterator, q *query.Query, loc
 	})
 
 	if err != nil {
-		queryIter.Error = err
+		queryIter.Err = err
 	}
 	close(queryIter.Next)
 	close(queryIter.Done)
diff --git a/database/storage/badger/badger_test.go b/database/storage/badger/badger_test.go
index f89ee90..9a66172 100644
--- a/database/storage/badger/badger_test.go
+++ b/database/storage/badger/badger_test.go
@@ -101,7 +101,7 @@ func TestBadger(t *testing.T) {
 	for _ = range it.Next {
 		cnt++
 	}
-	if it.Error != nil {
+	if it.Err != nil {
 		t.Fatal(err)
 	}
 	if cnt != 1 {
diff --git a/database/storage/injectbase.go b/database/storage/injectbase.go
new file mode 100644
index 0000000..1d3a734
--- /dev/null
+++ b/database/storage/injectbase.go
@@ -0,0 +1,61 @@
+package storage
+
+import (
+	"errors"
+
+	"github.com/Safing/portbase/database/iterator"
+	"github.com/Safing/portbase/database/query"
+	"github.com/Safing/portbase/database/record"
+)
+
+var (
+	errNotImplemented = errors.New("not implemented")
+)
+
+// InjectBase is a dummy base structure to reduce boilerplate code for injected storage interfaces.
+type InjectBase struct{}
+
+// Get returns a database record.
+func (i *InjectBase) Get(key string) (record.Record, error) {
+	return nil, errNotImplemented
+}
+
+// Put stores a record in the database.
+func (i *InjectBase) Put(m record.Record) error {
+	return errNotImplemented
+}
+
+// Delete deletes a record from the database.
+func (i *InjectBase) Delete(key string) error {
+	return errNotImplemented
+}
+
+// Query returns a an iterator for the supplied query.
+func (i *InjectBase) Query(q *query.Query, local, internal bool) (*iterator.Iterator, error) {
+	return nil, errNotImplemented
+}
+
+// ReadOnly returns whether the database is read only.
+func (i *InjectBase) ReadOnly() bool {
+	return true
+}
+
+// Injected returns whether the database is injected.
+func (i *InjectBase) Injected() bool {
+	return true
+}
+
+// Maintain runs a light maintenance operation on the database.
+func (i *InjectBase) Maintain() error {
+	return nil
+}
+
+// MaintainThorough runs a thorough maintenance operation on the database.
+func (i *InjectBase) MaintainThorough() error {
+	return nil
+}
+
+// Shutdown shuts down the database.
+func (i *InjectBase) Shutdown() error {
+	return nil
+}