diff --git a/.drone.yml b/.drone.yml
index 6182098..0261f19 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -3,12 +3,12 @@ name: default
 
 services:
   - name: vault
-    image: vault:1.7.1
+    image: vault:1.13.3
     environment:
       VAULT_DEV_ROOT_TOKEN_ID: dev
       VAULT_DEV_LISTEN_ADDRESS: 0.0.0.0:8200
   - name: etcd
-    image: bitnami/etcd:3
+    image: bitnami/etcd:3.5.11
     environment:
       ALLOW_NONE_AUTHENTICATION: yes
 
diff --git a/client.go b/client.go
index 508115e..15739e0 100644
--- a/client.go
+++ b/client.go
@@ -8,8 +8,8 @@ import (
 	"sync/atomic"
 )
 
-func Must(namespace, appName string, providers ...interface{}) *Client {
-	client, err := New(namespace, appName, providers...)
+func Must(providers ...interface{}) *Client {
+	client, err := New(providers...)
 	if err != nil {
 		panic(err)
 	}
@@ -17,10 +17,8 @@ func Must(namespace, appName string, providers ...interface{}) *Client {
 	return client
 }
 
-func New(namespace, appName string, providers ...interface{}) (*Client, error) {
+func New(providers ...interface{}) (*Client, error) {
 	client := &Client{
-		namespace: namespace,
-		appName:   appName,
 		providers: make([]Provider, len(providers)),
 	}
 
@@ -66,7 +64,7 @@ func (p *provider) init(ctx context.Context) error {
 	return nil
 }
 
-func (p *provider) Watch(ctx context.Context, key Key, callback WatchCallback) error {
+func (p *provider) Watch(ctx context.Context, callback WatchCallback, path ...string) error {
 	if err := p.init(ctx); err != nil {
 		return fmt.Errorf("init read:%w", err)
 	}
@@ -76,21 +74,21 @@ func (p *provider) Watch(ctx context.Context, key Key, callback WatchCallback) e
 		return nil
 	}
 
-	if err := watch.Watch(ctx, key, callback); err != nil {
+	if err := watch.Watch(ctx, callback, path...); err != nil {
 		return fmt.Errorf("factory provider: %w", err)
 	}
 
 	return nil
 }
 
-func (p *provider) Read(ctx context.Context, key Key) (Variable, error) {
+func (p *provider) Value(ctx context.Context, path ...string) (Value, error) {
 	if err := p.init(ctx); err != nil {
-		return Variable{}, fmt.Errorf("init read:%w", err)
+		return nil, fmt.Errorf("init read:%w", err)
 	}
 
-	variable, err := p.provider.Read(ctx, key)
+	variable, err := p.provider.Value(ctx, path...)
 	if err != nil {
-		return Variable{}, fmt.Errorf("factory provider: %w", err)
+		return nil, fmt.Errorf("factory provider: %w", err)
 	}
 
 	return variable, nil
@@ -98,53 +96,34 @@ func (p *provider) Read(ctx context.Context, key Key) (Variable, error) {
 
 type Client struct {
 	providers []Provider
-	appName   string
-	namespace string
 }
 
-func (c *Client) key(name string) Key {
-	return Key{
-		Name:      name,
-		AppName:   c.appName,
-		Namespace: c.namespace,
-	}
+func (c *Client) Name() string {
+	return "client"
 }
 
 // Value get value by name.
-// nolint: ireturn
-func (c *Client) Value(ctx context.Context, name string) (Value, error) {
-	variable, err := c.Variable(ctx, name)
-	if err != nil {
-		return nil, fmt.Errorf("variable:%w", err)
-	}
-
-	return variable.Value, nil
-}
-
-func (c *Client) Variable(ctx context.Context, name string) (Variable, error) {
+func (c *Client) Value(ctx context.Context, path ...string) (Value, error) {
 	var (
-		variable Variable
-		err      error
+		value Value
+		err   error
 	)
 
-	key := c.key(name)
-
 	for _, provider := range c.providers {
-		variable, err = provider.Read(ctx, key)
-		if err == nil || !(errors.Is(err, ErrVariableNotFound) || errors.Is(err, ErrInitFactory)) {
+		value, err = provider.Value(ctx, path...)
+		if err == nil || !(errors.Is(err, ErrValueNotFound) || errors.Is(err, ErrInitFactory)) {
 			break
 		}
 	}
 
 	if err != nil {
-		return variable, fmt.Errorf("client failed get variable: %w", err)
+		return value, fmt.Errorf("client failed get value: %w", err)
 	}
 
-	return variable, nil
+	return value, nil
 }
 
-func (c *Client) Watch(ctx context.Context, name string, callback WatchCallback) error {
-	key := c.key(name)
+func (c *Client) Watch(ctx context.Context, callback WatchCallback, path ...string) error {
 
 	for idx, prov := range c.providers {
 		provider, ok := prov.(WatchProvider)
@@ -152,9 +131,9 @@ func (c *Client) Watch(ctx context.Context, name string, callback WatchCallback)
 			continue
 		}
 
-		err := provider.Watch(ctx, key, callback)
+		err := provider.Watch(ctx, callback, path...)
 		if err != nil {
-			if errors.Is(err, ErrVariableNotFound) || errors.Is(err, ErrInitFactory) {
+			if errors.Is(err, ErrValueNotFound) || errors.Is(err, ErrInitFactory) {
 				continue
 			}
 
diff --git a/client_example_test.go b/client_example_test.go
index 7550fb5..56de1aa 100644
--- a/client_example_test.go
+++ b/client_example_test.go
@@ -20,6 +20,11 @@ import (
 )
 
 func ExampleClient_Value() {
+	const (
+		namespace = "fdevs"
+		appName   = "config"
+	)
+
 	ctx := context.Background()
 	_ = os.Setenv("FDEVS_CONFIG_LISTEN", "8080")
 	_ = os.Setenv("FDEVS_CONFIG_HOST", "localhost")
@@ -51,11 +56,11 @@ func ExampleClient_Value() {
 	// read json config
 	jsonConfig := test.ReadFile("config.json")
 
-	config, err := config.New(test.Namespace, test.AppName,
+	config, err := config.New(
 		arg.New(),
-		env.New(),
-		etcd.NewProvider(etcdClient),
-		vault.NewSecretKV2(vaultClient),
+		env.New(test.Namespace, test.AppName),
+		etcd.NewProvider(namespace, appName, etcdClient),
+		vault.NewSecretKV2(namespace, appName, vaultClient),
 		json.New(jsonConfig),
 	)
 	if err != nil {
@@ -64,30 +69,30 @@ func ExampleClient_Value() {
 		return
 	}
 
-	dsn, err := config.Value(ctx, "example:dsn")
+	dsn, err := config.Value(ctx, "example", "dsn")
 	if err != nil {
-		log.Print(err)
+		log.Print("example:dsn", err)
 
 		return
 	}
 
 	port, err := config.Value(ctx, "listen")
 	if err != nil {
-		log.Print(err)
+		log.Print("listen", err)
 
 		return
 	}
 
 	enabled, err := config.Value(ctx, "maintain")
 	if err != nil {
-		log.Print(err)
+		log.Print("maintain", err)
 
 		return
 	}
 
 	title, err := config.Value(ctx, "app.name.title")
 	if err != nil {
-		log.Print(err)
+		log.Print("app.name.title", err)
 
 		return
 	}
@@ -125,6 +130,11 @@ func ExampleClient_Value() {
 }
 
 func ExampleClient_Watch() {
+	const (
+		namespace = "fdevs"
+		appName   = "config"
+	)
+
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
@@ -155,10 +165,10 @@ func ExampleClient_Watch() {
 		}
 	}()
 
-	watcher, err := config.New(test.Namespace, test.AppName,
-		watcher.New(time.Microsecond, env.New()),
+	watcher, err := config.New(
+		watcher.New(time.Microsecond, env.New(test.Namespace, test.AppName)),
 		watcher.New(time.Microsecond, yaml.NewWatch("test/fixture/config.yaml")),
-		etcd.NewProvider(etcdClient),
+		etcd.NewProvider(namespace, appName, etcdClient),
 	)
 	if err != nil {
 		log.Print(err)
@@ -169,10 +179,10 @@ func ExampleClient_Watch() {
 	wg := sync.WaitGroup{}
 	wg.Add(2)
 
-	err = watcher.Watch(ctx, "example_enable", func(ctx context.Context, oldVar, newVar config.Variable) {
-		fmt.Println("update ", oldVar.Provider, " variable:", oldVar.Name, ", old: ", oldVar.Value.Bool(), " new:", newVar.Value.Bool())
+	err = watcher.Watch(ctx, func(ctx context.Context, oldVar, newVar config.Value) {
+		fmt.Println("update example_enable old: ", oldVar.Bool(), " new:", newVar.Bool())
 		wg.Done()
-	})
+	}, "example_enable")
 	if err != nil {
 		log.Print(err)
 
@@ -181,10 +191,10 @@ func ExampleClient_Watch() {
 
 	_ = os.Setenv("FDEVS_CONFIG_EXAMPLE_ENABLE", "false")
 
-	err = watcher.Watch(ctx, "example_db_dsn", func(ctx context.Context, oldVar, newVar config.Variable) {
-		fmt.Println("update ", oldVar.Provider, " variable:", oldVar.Name, ", old: ", oldVar.Value.String(), " new:", newVar.Value.String())
+	err = watcher.Watch(ctx, func(ctx context.Context, oldVar, newVar config.Value) {
+		fmt.Println("update example_db_dsn old: ", oldVar.String(), " new:", newVar.String())
 		wg.Done()
-	})
+	}, "example_db_dsn")
 	if err != nil {
 		log.Print(err)
 
@@ -202,8 +212,8 @@ func ExampleClient_Watch() {
 	wg.Wait()
 
 	// Output:
-	// update  env  variable: FDEVS_CONFIG_EXAMPLE_ENABLE , old:  true  new: false
-	// update  etcd  variable: fdevs/config/example_db_dsn , old:  pgsql://user@pass:127.0.0.1:5432  new: mysql://localhost:5432
+	// update example_enable old:  true  new: false
+	// update example_db_dsn old:  pgsql://user@pass:127.0.0.1:5432  new: mysql://localhost:5432
 }
 
 func ExampleClient_Value_factory() {
@@ -219,10 +229,10 @@ func ExampleClient_Value_factory() {
 
 	os.Args = []string{"main.go", "--config-json=config.json", "--config-yaml=test/fixture/config.yaml"}
 
-	config, err := config.New(test.Namespace, test.AppName,
+	config, err := config.New(
 		arg.New(),
-		env.New(),
-		config.Factory(func(ctx context.Context, cfg config.ReadConfig) (config.Provider, error) {
+		env.New(test.Namespace, test.AppName),
+		config.Factory(func(ctx context.Context, cfg config.Provider) (config.Provider, error) {
 			val, err := cfg.Value(ctx, "config-json")
 			if err != nil {
 				return nil, fmt.Errorf("failed read config file:%w", err)
@@ -231,7 +241,7 @@ func ExampleClient_Value_factory() {
 
 			return json.New(jsonConfig), nil
 		}),
-		config.Factory(func(ctx context.Context, cfg config.ReadConfig) (config.Provider, error) {
+		config.Factory(func(ctx context.Context, cfg config.Provider) (config.Provider, error) {
 			val, err := cfg.Value(ctx, "config-yaml")
 			if err != nil {
 				return nil, fmt.Errorf("failed read config file:%w", err)
@@ -258,14 +268,14 @@ func ExampleClient_Value_factory() {
 		return
 	}
 
-	title, err := config.Value(ctx, "app.name.title")
+	title, err := config.Value(ctx, "app", "name", "title")
 	if err != nil {
 		log.Print(err)
 
 		return
 	}
 
-	yamlTitle, err := config.Value(ctx, "app/title")
+	yamlTitle, err := config.Value(ctx, "app", "title")
 	if err != nil {
 		log.Print(err)
 
diff --git a/definition/defenition.go b/definition/defenition.go
new file mode 100755
index 0000000..64385e1
--- /dev/null
+++ b/definition/defenition.go
@@ -0,0 +1,29 @@
+package definition
+
+import (
+	"fmt"
+)
+
+func New() Definition {
+	return Definition{}
+}
+
+type Definition struct {
+	options Options
+}
+
+func (d *Definition) Add(opts ...Option) *Definition {
+	d.options = append(d.options, opts...)
+
+	return d
+}
+
+func (d *Definition) View(handle func(Option) error) error {
+	for idx, opt := range d.options {
+		if err := handle(opt); err != nil {
+			return fmt.Errorf("%s[%d]:%w", opt.Kind(), idx, err)
+		}
+	}
+
+	return nil
+}
diff --git a/definition/generate/generator.go b/definition/generate/generator.go
new file mode 100644
index 0000000..fdb9e93
--- /dev/null
+++ b/definition/generate/generator.go
@@ -0,0 +1,70 @@
+package generate
+
+import (
+	"fmt"
+	"io"
+
+	"gitoa.ru/go-4devs/config/definition"
+)
+
+type Generator struct {
+	pkg string
+	ViewOption
+	Imp           Imports
+	errs          []error
+	defaultErrors []string
+}
+
+func (g Generator) Pkg() string {
+	return g.pkg
+}
+
+func (g Generator) Imports() []Import {
+	return g.Imp.Imports()
+}
+
+func (g Generator) Handle(w io.Writer, data Handler, opt definition.Option) error {
+	handle := get(opt.Kind())
+
+	return handle(w, data, opt)
+}
+
+func (g Generator) StructName() string {
+	return FuncName(g.Prefix + "_" + g.Struct + "_" + g.Suffix)
+}
+
+func (g Generator) Options() ViewOption {
+	return g.ViewOption
+}
+
+func (g Generator) Keys() []string {
+	return nil
+}
+
+func (g Generator) DefaultErrors() []string {
+	if len(g.defaultErrors) > 0 {
+		return g.defaultErrors
+	}
+
+	if len(g.ViewOption.Errors.Default) > 0 {
+		g.Imp.Adds("errors")
+	}
+
+	g.defaultErrors = make([]string, len(g.ViewOption.Errors.Default))
+	for idx, name := range g.ViewOption.Errors.Default {
+		short, err := g.AddType(name)
+		if err != nil {
+			g.errs = append(g.errs, fmt.Errorf("add default error[%d]:%w", idx, err))
+
+			return nil
+		}
+
+		g.defaultErrors[idx] = short
+	}
+
+	return g.defaultErrors
+}
+
+func (g *Generator) AddType(pkg string) (string, error) {
+	return g.Imp.AddType(pkg)
+}
diff --git a/definition/generate/helpers.go b/definition/generate/helpers.go
new file mode 100644
index 0000000..b3cdf0c
--- /dev/null
+++ b/definition/generate/helpers.go
@@ -0,0 +1,16 @@
+package generate
+
+import (
+	"errors"
+
+	"github.com/iancoleman/strcase"
+)
+
+var (
+	ErrNotFound     = errors.New("not found")
+	ErrAlreadyExist = errors.New("already exist")
+)
+
+func FuncName(in string) string {
+	return strcase.ToCamel(in)
+}
diff --git a/definition/generate/imports.go b/definition/generate/imports.go
new file mode 100644
index 0000000..fc40a59
--- /dev/null
+++ b/definition/generate/imports.go
@@ -0,0 +1,87 @@
+package generate
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+func NewImports() Imports {
+	return Imports{
+		data: make(map[string]string),
+	}
+}
+
+type Imports struct {
+	data map[string]string
+}
+
+func (i Imports) Imports() []Import {
+	imports := make([]Import, 0, len(i.data))
+	for name, alias := range i.data {
+		imports = append(imports, Import{
+			Package: name,
+			Alias:   alias,
+		})
+	}
+
+	return imports
+}
+
+func (i *Imports) Short(fullType string) (string, error) {
+	idx := strings.LastIndexByte(fullType, '.')
+	if idx == -1 {
+		return "", fmt.Errorf("unexpected")
+	}
+	if alias, ok := i.data[fullType[:idx]]; ok {
+		return alias + fullType[idx:], nil
+	}
+
+	return "", fmt.Errorf("%w alias for pkg %v", ErrNotFound, fullType[:idx])
+}
+
+func (i *Imports) AddType(fullType string) (string, error) {
+	idx := strings.LastIndexByte(fullType, '.')
+	if idx == -1 {
+		return "", fmt.Errorf("unexpected")
+	}
+
+	imp := i.Add(fullType[:idx])
+
+	return imp.Alias + fullType[idx:], nil
+
+}
+
+func (i *Imports) Adds(pkgs ...string) {
+	for _, pkg := range pkgs {
+		i.Add(pkg)
+	}
+}
+
+func (i *Imports) Add(pkg string) Import {
+	alias := pkg
+	idx := strings.LastIndexByte(pkg, '/')
+	if idx != -1 {
+		alias = pkg[idx+1:]
+	}
+	if al, ok := i.data[pkg]; ok {
+		return Import{Package: pkg, Alias: al}
+	}
+
+	for _, al := range i.data {
+		if al == alias {
+			alias += strconv.Itoa(len(i.data))
+		}
+	}
+	i.data[pkg] = alias
+
+	return Import{
+		Alias:   alias,
+		Package: pkg,
+	}
+}
+
+type Import struct {
+	Alias   string
+	Package string
+}
diff --git a/definition/generate/run.go b/definition/generate/run.go
new file mode 100644
index 0000000..a0a0029
--- /dev/null
+++ b/definition/generate/run.go
@@ -0,0 +1,38 @@
+package generate
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"gitoa.ru/go-4devs/config/definition"
+)
+
+func Run(w io.Writer, pkgName string, defs definition.Definition, viewOpt ViewOption) error {
+	gen := Generator{
+		pkg:        pkgName,
+		ViewOption: viewOpt,
+		Imp:        NewImports(),
+	}
+
+	gen.Imp.Adds("gitoa.ru/go-4devs/config", "fmt", "context")
+
+	var view bytes.Buffer
+	err := defs.View(func(o definition.Option) error {
+		return gen.Handle(&view, &gen, o)
+	})
+	if err != nil {
+		return fmt.Errorf("render options:%w", err)
+	}
+
+	if err := tpl.Execute(w, gen); err != nil {
+		return fmt.Errorf("render base:%w", err)
+	}
+
+	_, cerr := io.Copy(w, &view)
+	if cerr != nil {
+		return fmt.Errorf("copy error:%w", cerr)
+	}
+
+	return nil
+}
diff --git a/definition/generate/template.go b/definition/generate/template.go
new file mode 100644
index 0000000..34ed076
--- /dev/null
+++ b/definition/generate/template.go
@@ -0,0 +1,41 @@
+package generate
+
+import "text/template"
+
+var tpl = template.Must(template.New("tpls").Parse(baseTemplate))
+
+var baseTemplate = `// Code generated gitoa.ru/go-4devs/config DO NOT EDIT.
+package {{.Pkg}}
+
+import (
+    {{range .Imports}}
+    {{- .Alias }}"{{ .Package }}"
+    {{end}}
+)
+
+func With{{.StructName}}Log(log func(context.Context, string, ...any)) func(*{{.StructName}}) {
+	return func(ci *{{.StructName}}) {
+		ci.log = log
+	}
+}
+
+func New{{.StructName}}(prov config.Provider, opts ...func(*{{.StructName}})) {{.StructName}} {
+	i := {{.StructName}}{
+		Provider: prov,
+		log: func(_ context.Context, format string, args ...any) {
+			fmt.Printf(format, args...)
+		},
+	}
+
+	for _, opt := range opts {
+		opt(&i)
+	}
+
+	return i
+}
+
+type {{.StructName}} struct {
+	config.Provider
+	log   func(context.Context, string, ...any)
+}
+`
diff --git a/definition/generate/view.go b/definition/generate/view.go
new file mode 100644
index 0000000..31f5a68
--- /dev/null
+++ b/definition/generate/view.go
@@ -0,0 +1,60 @@
+package generate
+
+import (
+	"fmt"
+	"io"
+	"sync"
+
+	"gitoa.ru/go-4devs/config/definition"
+)
+
+var handlers = sync.Map{}
+
+func Add(kind string, h Handle) error {
+	_, ok := handlers.Load(kind)
+	if ok {
+		return fmt.Errorf("kind %v: %w", kind, ErrAlreadyExist)
+	}
+
+	handlers.Store(kind, h)
+	return nil
+}
+
+func get(kind string) Handle {
+	h, ok := handlers.Load(kind)
+	if !ok {
+		return func(w io.Writer, h Handler, o definition.Option) error {
+			return fmt.Errorf("handler by %v:%w", kind, ErrNotFound)
+		}
+	}
+
+	return h.(Handle)
+}
+
+func MustAdd(kind string, h Handle) {
+	if err := Add(kind, h); err != nil {
+		panic(err)
+	}
+}
+
+type Handle func(io.Writer, Handler, definition.Option) error
+
+type Handler interface {
+	StructName() string
+	Handle(io.Writer, Handler, definition.Option) error
+	Options() ViewOption
+	Keys() []string
+	AddType(fullName string) (string, error)
+	DefaultErrors() []string
+}
+
+type ViewOption struct {
+	Prefix, Suffix string
+	Context        bool
+	Struct         string
+	Errors         ViewErrors
+}
+
+type ViewErrors struct {
+	Default []string
+}
diff --git a/definition/group/group.go b/definition/group/group.go
new file mode 100755
index 0000000..32328c3
--- /dev/null
+++ b/definition/group/group.go
@@ -0,0 +1,27 @@
+package group
+
+import (
+	"gitoa.ru/go-4devs/config/definition"
+)
+
+const Kind = "group"
+
+var _ definition.Option = Group{}
+
+func New(name, desc string, opts ...definition.Option) Group {
+	return Group{
+		Name:        name,
+		Description: desc,
+		Options:     opts,
+	}
+}
+
+type Group struct {
+	Options     definition.Options
+	Name        string
+	Description string
+}
+
+func (o Group) Kind() string {
+	return Kind
+}
diff --git a/definition/group/view.go b/definition/group/view.go
new file mode 100644
index 0000000..250ad11
--- /dev/null
+++ b/definition/group/view.go
@@ -0,0 +1,85 @@
+package group
+
+import (
+	"fmt"
+	"io"
+	"text/template"
+
+	"gitoa.ru/go-4devs/config/definition"
+	"gitoa.ru/go-4devs/config/definition/generate"
+)
+
+func init() {
+	generate.MustAdd(Kind, handle)
+}
+
+func handle(w io.Writer, data generate.Handler, option definition.Option) error {
+	group, ok := option.(Group)
+	if !ok {
+		return fmt.Errorf("uexepected type:%T", option)
+	}
+	viewData := View{
+		Group:      group,
+		ParentName: data.StructName(),
+		ViewOption: data.Options(),
+	}
+
+	err := tpl.Execute(w, viewData)
+
+	if err != nil {
+		return fmt.Errorf("render group:%w", err)
+	}
+
+	childData := ChildData{
+		Handler:    data,
+		structName: viewData.StructName(),
+		keys:       append(data.Keys(), group.Name),
+	}
+	for idx, child := range group.Options {
+		if cerr := data.Handle(w, childData, child); cerr != nil {
+			return fmt.Errorf("render group child[%d]:%w", idx, cerr)
+		}
+	}
+
+	return nil
+}
+
+type ChildData struct {
+	generate.Handler
+	structName string
+	keys       []string
+}
+
+func (c ChildData) StructName() string {
+	return c.structName
+}
+
+func (v ChildData) Keys() []string {
+	return v.keys
+}
+
+type View struct {
+	Group
+	ParentName string
+	generate.ViewOption
+}
+
+func (v View) FuncName() string {
+	return generate.FuncName(v.Name)
+}
+
+func (v View) StructName() string {
+	return generate.FuncName(v.Prefix + v.Name + v.Suffix)
+}
+
+var tpl = template.Must(template.New("tpls").Parse(tplw))
+
+var tplw = `type {{.StructName}} struct {
+    {{.ParentName}}
+}
+
+// {{.FuncName}} {{.Description}}.
+func (i {{.ParentName}}) {{.FuncName}}() {{.StructName}} {
+	return {{.StructName}}{i}
+}
+`
diff --git a/definition/option.go b/definition/option.go
new file mode 100755
index 0000000..9a3bd57
--- /dev/null
+++ b/definition/option.go
@@ -0,0 +1,27 @@
+package definition
+
+type Option interface {
+	Kind() string
+}
+
+type Options []Option
+
+func (s Options) Len() int      { return len(s) }
+func (s Options) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+
+type Params []Param
+
+func (p Params) Get(name string) (any, bool) {
+	for _, param := range p {
+		if param.Name == name {
+			return param.Value, true
+		}
+	}
+
+	return nil, false
+}
+
+type Param struct {
+	Name  string
+	Value any
+}
diff --git a/definition/option/option.go b/definition/option/option.go
new file mode 100755
index 0000000..1936f2f
--- /dev/null
+++ b/definition/option/option.go
@@ -0,0 +1,100 @@
+package option
+
+import (
+	"gitoa.ru/go-4devs/config/definition"
+)
+
+var _ definition.Option = Option{}
+
+const (
+	Kind = "option"
+)
+
+const (
+	TypeString   = "string"
+	TypeInt      = "int"
+	TypeInt64    = "int64"
+	TypeUint     = "uint"
+	TypeUint64   = "uint64"
+	TypeFloat64  = "float64"
+	TypeBool     = "bool"
+	TypeTime     = "time.Time"
+	TypeDuration = "time.Duration"
+)
+
+func Default(v any) func(*Option) {
+	return func(o *Option) {
+		o.Default = v
+	}
+}
+
+func New(name, desc string, vtype any, opts ...func(*Option)) Option {
+	option := Option{
+		Name:        name,
+		Description: desc,
+		Type:        vtype,
+	}
+
+	for _, opt := range opts {
+		opt(&option)
+	}
+
+	return option
+}
+
+type Option struct {
+	Name        string
+	Description string
+	Type        any
+	Default     any
+	Params      definition.Params
+}
+
+func (o Option) WithParams(params ...definition.Param) Option {
+	return Option{
+		Name:        o.Name,
+		Description: o.Description,
+		Type:        o.Type,
+		Params:      append(params, o.Params...),
+	}
+}
+
+func (o Option) Kind() string {
+	return Kind
+}
+
+func Time(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeTime, opts...)
+}
+
+func Duration(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeDuration, opts...)
+}
+
+func String(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeString, opts...)
+}
+
+func Int(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeInt, opts...)
+}
+
+func Int64(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeInt64, opts...)
+}
+
+func Uint(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeUint, opts...)
+}
+
+func Uint64(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeUint64, opts...)
+}
+
+func Float64(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeFloat64, opts...)
+}
+
+func Bool(name, desc string, opts ...func(*Option)) Option {
+	return New(name, desc, TypeBool, opts...)
+}
diff --git a/definition/option/tpl/option.tmpl b/definition/option/tpl/option.tmpl
new file mode 100644
index 0000000..73f5532
--- /dev/null
+++ b/definition/option/tpl/option.tmpl
@@ -0,0 +1,33 @@
+// read{{.FuncName}} {{.Description}}.
+func (i {{.StructName}}) read{{.FuncName}}(ctx context.Context) (v {{.Type}},e error) {
+	val, err := i.Value(ctx, {{ .ParentKeys }}"{{ .Name }}")
+	if err != nil {
+        {{if .HasDefault}}
+        {{$default := .Default}}
+        {{range .DefaultErrors}}
+        if errors.Is(err,{{.}}){
+            return {{$default}}
+		}
+        {{end}}
+        {{end}}
+        return v, fmt.Errorf("read {{.Keys}}:%w",err)
+	}
+
+	{{.Parse "val" "v" .Keys }}
+}
+
+// Read{{.FuncName}} {{.Description}}.
+func (i {{.StructName}}) Read{{.FuncName}}(ctx context.Context) ({{.Type}}, error) {
+    return i.read{{.FuncName}}(ctx)
+}
+
+// {{.FuncName}} {{.Description}}.
+func (i {{.StructName}}) {{.FuncName}}({{if .Context}} ctx context.Context {{end}}) {{.Type}} {
+    {{if not .Context}} ctx := context.Background() {{end}}
+	val, err := i.read{{.FuncName}}(ctx)
+	if err != nil {
+		i.log(ctx, "get {{.Keys}}: %v", err)
+	}
+
+	return val
+}
diff --git a/definition/option/tpl/parse.tmpl b/definition/option/tpl/parse.tmpl
new file mode 100644
index 0000000..0cbc58b
--- /dev/null
+++ b/definition/option/tpl/parse.tmpl
@@ -0,0 +1,3 @@
+{{block "Parse" .}}
+return {{.ValName}}.Parse{{ .FuncType}}()
+{{end}}
\ No newline at end of file
diff --git a/definition/option/tpl/unmarshal_json.tmpl b/definition/option/tpl/unmarshal_json.tmpl
new file mode 100644
index 0000000..b54d7fb
--- /dev/null
+++ b/definition/option/tpl/unmarshal_json.tmpl
@@ -0,0 +1,8 @@
+{{block "UnmarshalJSON" . }}
+	pval, perr := {{.ValName}}.ParseString()
+	if perr != nil {
+		return {{.Value}}, fmt.Errorf("read {{.Keys}}:%w", perr)
+	}
+
+	return {{.Value}}, {{.Value}}.UnmarshalJSON([]byte(pval))
+{{end}}
\ No newline at end of file
diff --git a/definition/option/tpl/unmarshal_text.tmpl b/definition/option/tpl/unmarshal_text.tmpl
new file mode 100644
index 0000000..fbb8105
--- /dev/null
+++ b/definition/option/tpl/unmarshal_text.tmpl
@@ -0,0 +1,8 @@
+{{block "UnmarshalText" . }}
+	pval, perr := {{.ValName}}.ParseString()
+	if perr != nil {
+		return {{.Value}}, fmt.Errorf("read {{.Keys}}:%w", perr)
+	}
+
+	return {{.Value}}, {{.Value}}.UnmarshalText([]byte(pval))
+{{end}}
\ No newline at end of file
diff --git a/definition/option/view.go b/definition/option/view.go
new file mode 100644
index 0000000..777d4e4
--- /dev/null
+++ b/definition/option/view.go
@@ -0,0 +1,226 @@
+package option
+
+import (
+	"bytes"
+	"embed"
+	"encoding"
+	"encoding/json"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"text/template"
+	"time"
+
+	"gitoa.ru/go-4devs/config/definition"
+	"gitoa.ru/go-4devs/config/definition/generate"
+)
+
+//go:embed tpl/*
+var tpls embed.FS
+
+var tpl = template.Must(template.New("tpls").ParseFS(tpls, "tpl/*.tmpl"))
+
+func init() {
+	generate.MustAdd(Kind, Handle(tpl.Lookup("option.tmpl")))
+}
+
+func Handle(tpl *template.Template) generate.Handle {
+	return func(w io.Writer, h generate.Handler, o definition.Option) error {
+		opt, _ := o.(Option)
+		if err := tpl.Execute(w, View{Option: opt, Handler: h}); err != nil {
+			return fmt.Errorf("option tpl:%w", err)
+		}
+
+		return nil
+	}
+}
+
+type View struct {
+	Option
+	generate.Handler
+}
+
+func (v View) Context() bool {
+	return v.Options().Context
+}
+
+func (v View) FuncName() string {
+	if funcName, ok := v.Option.Params.Get(ViewParamFunctName); ok {
+		return funcName.(string)
+	}
+
+	return generate.FuncName(v.Name)
+}
+
+func (v View) Description() string {
+	if desc, ok := v.Option.Params.Get(ViewParamDescription); ok {
+		return desc.(string)
+	}
+
+	return v.Option.Description
+}
+
+func (v View) Default() string {
+	switch data := v.Option.Default.(type) {
+	case time.Time:
+		return fmt.Sprintf("time.Parse(%q,time.RFC3339Nano)", data.Format(time.RFC3339Nano))
+	case time.Duration:
+		return fmt.Sprintf("time.ParseDuration(%q)", data)
+	default:
+		return fmt.Sprintf("%#v, nil", data)
+	}
+}
+
+func (v View) HasDefault() bool {
+	return v.Option.Default != nil
+}
+
+func (v View) ParentKeys() string {
+	if len(v.Handler.Keys()) > 0 {
+		return `"` + strings.Join(v.Handler.Keys(), `","`) + `",`
+	}
+
+	return ""
+}
+
+func (v View) Type() string {
+	slice := ""
+	if vtype, ok := v.Option.Type.(string); ok {
+		if strings.Contains(vtype, ".") {
+			if name, err := v.AddType(vtype); err == nil {
+				return slice + name
+			}
+		}
+		return vtype
+	}
+
+	rtype := reflect.TypeOf(v.Option.Type)
+
+	if rtype.PkgPath() == "" {
+		return rtype.String()
+	}
+
+	if rtype.Kind() == reflect.Slice {
+		slice = "[]"
+	}
+
+	short, err := v.AddType(rtype.PkgPath() + "." + rtype.Name())
+	if err != nil {
+		return err.Error()
+	}
+
+	return slice + short
+}
+
+func (v View) FuncType() string {
+	return generate.FuncName(v.Type())
+}
+
+func (v View) Parse(valName string, value string, keys []string) string {
+
+	h := parser(v.Option.Type)
+
+	data, err := h(ParseData{
+		Value:   value,
+		ValName: valName,
+		Keys:    keys,
+		View:    v,
+	})
+	if err != nil {
+		return err.Error()
+	}
+
+	return data
+}
+
+var parses = map[string]func(data ParseData) (string, error){
+	typesIntreface[0].Name(): func(data ParseData) (string, error) {
+		var b bytes.Buffer
+
+		err := tpl.ExecuteTemplate(&b, "unmarshal_text.tmpl", data)
+		if err != nil {
+			return "", err
+		}
+
+		return b.String(), nil
+	},
+	typesIntreface[1].Name(): func(data ParseData) (string, error) {
+		var b bytes.Buffer
+
+		err := tpl.ExecuteTemplate(&b, "unmarshal_json.tmpl", data)
+		if err != nil {
+			return "", err
+		}
+
+		return b.String(), nil
+	},
+	TypeInt:     internal,
+	TypeInt64:   internal,
+	TypeBool:    internal,
+	TypeString:  internal,
+	TypeFloat64: internal,
+	TypeUint:    internal,
+	TypeUint64:  internal,
+	"time.Duration": func(data ParseData) (string, error) {
+		return fmt.Sprintf("return %s.ParseDuration()", data.ValName), nil
+	},
+	"time.Time": func(data ParseData) (string, error) {
+		return fmt.Sprintf("return %s.ParseTime()", data.ValName), nil
+	},
+	"any": func(data ParseData) (string, error) {
+		return fmt.Sprintf("return %[2]s, %[1]s.Unmarshal(&%[2]s)", data.ValName, data.Value), nil
+	},
+}
+
+func internal(data ParseData) (string, error) {
+	var b bytes.Buffer
+	err := tpl.ExecuteTemplate(&b, "parse.tmpl", data)
+	if err != nil {
+		return "", err
+	}
+
+	return b.String(), nil
+}
+
+var (
+	typesIntreface = [...]reflect.Type{
+		reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem(),
+		reflect.TypeOf((*json.Unmarshaler)(nil)).Elem(),
+	}
+)
+
+func parser(data any) func(ParseData) (string, error) {
+	vtype := reflect.TypeOf(data)
+	name := vtype.Name()
+	if v, ok := data.(string); ok {
+		name = v
+	}
+
+	if vtype.Kind() == reflect.Slice {
+		return parses["any"]
+	}
+
+	if h, ok := parses[name]; ok {
+		return h
+	}
+
+	for _, extypes := range typesIntreface {
+		if vtype.Implements(extypes) {
+			return parses[extypes.Name()]
+		}
+
+		if vtype.Kind() != reflect.Ptr && reflect.PointerTo(vtype).Implements(extypes) {
+			return parses[extypes.Name()]
+		}
+	}
+
+	return parses["any"]
+}
+
+type ParseData struct {
+	Value   string
+	ValName string
+	Keys    []string
+	View
+}
diff --git a/definition/option/view_params.go b/definition/option/view_params.go
new file mode 100644
index 0000000..36c4ee1
--- /dev/null
+++ b/definition/option/view_params.go
@@ -0,0 +1,6 @@
+package option
+
+const (
+	ViewParamFunctName   = "view.funcName"
+	ViewParamDescription = "view.description"
+)
diff --git a/definition/proto/proto.go b/definition/proto/proto.go
new file mode 100644
index 0000000..439487a
--- /dev/null
+++ b/definition/proto/proto.go
@@ -0,0 +1,27 @@
+package proto
+
+import (
+	"gitoa.ru/go-4devs/config/definition"
+)
+
+const Kind = "proto"
+
+func New(name, desc string, opt definition.Option, opts ...func(*Proto)) Proto {
+	pr := Proto{
+		Name:        name,
+		Description: desc,
+		Option:      opt,
+	}
+
+	return pr
+}
+
+type Proto struct {
+	Name        string
+	Description string
+	Option      definition.Option
+}
+
+func (p Proto) Kind() string {
+	return Kind
+}
diff --git a/definition/proto/view.go b/definition/proto/view.go
new file mode 100644
index 0000000..b046cac
--- /dev/null
+++ b/definition/proto/view.go
@@ -0,0 +1,76 @@
+package proto
+
+import (
+	"fmt"
+	"io"
+	"strings"
+	"text/template"
+
+	"gitoa.ru/go-4devs/config/definition"
+	"gitoa.ru/go-4devs/config/definition/generate"
+	"gitoa.ru/go-4devs/config/definition/option"
+)
+
+func init() {
+	generate.MustAdd(Kind, handle)
+}
+
+func handle(w io.Writer, data generate.Handler, opt definition.Option) error {
+	proto, ok := opt.(Proto)
+	if !ok {
+		return fmt.Errorf("uexepected type:%T", opt)
+	}
+	if viewOpt, ok := proto.Option.(option.Option); ok {
+		viewOpt = viewOpt.WithParams(
+			definition.Param{
+				Name:  option.ViewParamFunctName,
+				Value: generate.FuncName(proto.Name) + generate.FuncName(viewOpt.Name),
+			},
+			definition.Param{
+				Name:  option.ViewParamDescription,
+				Value: proto.Description + " " + viewOpt.Description,
+			},
+		)
+
+		return option.Handle(tpl)(w, data, viewOpt)
+	}
+
+	return fmt.Errorf("not support option type")
+}
+
+var tpl = template.Must(template.New("tpls").Funcs(template.FuncMap{"join": strings.Join}).Parse(templateOption))
+
+var templateOption = `// read{{.FuncName}} {{.Description}}.
+func (i {{.StructName}}) read{{.FuncName}}(ctx context.Context, key string) (v {{.Type}},e error) {
+	val, err := i.Value(ctx, {{ .ParentKeys }} key, "{{.Name}}")
+	if err != nil {
+        {{if .HasDefault}}
+        {{$default := .Default}}
+        {{range .DefaultErrors}}
+        if errors.Is(err,{{.}}){
+            return {{$default}}
+		}
+        {{end}}
+        {{end}}
+        return v, fmt.Errorf("read {{.Keys}}:%w",err)
+	}
+
+	{{.Parse "val" "v" .Keys }}
+}
+
+// Read{{.FuncName}} {{.Description}}.
+func (i {{.StructName}}) Read{{.FuncName}}(ctx context.Context, key string) ({{.Type}}, error) {
+    return i.read{{.FuncName}}(ctx, key)
+}
+
+// {{.FuncName}} {{.Description}}.
+func (i {{.StructName}}) {{.FuncName}}({{if .Context}} ctx context.Context, {{end}} key string) {{.Type}} {
+    {{if not .Context}} ctx := context.Background() {{end}}
+	val, err := i.read{{.FuncName}}(ctx, key)
+	if err != nil {
+		i.log(ctx, "get {{.Keys}}: %v", err)
+	}
+
+	return val
+}
+`
diff --git a/docker-compose.yml b/docker-compose.yml
index a41d67b..92a0b4c 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -2,7 +2,7 @@ version: '3'
 
 services:
   vault:
-    image: vault:latest
+    image: vault:1.13.3
     cap_add:
       - IPC_LOCK
     ports:
@@ -10,7 +10,7 @@ services:
     environment: 
       VAULT_DEV_ROOT_TOKEN_ID: "dev"
   etcd:
-    image: bitnami/etcd
+    image: bitnami/etcd:3.5.11
     environment: 
       ALLOW_NONE_AUTHENTICATION: "yes"
     ports: 
diff --git a/error.go b/error.go
index ddd9d74..93c30be 100644
--- a/error.go
+++ b/error.go
@@ -3,8 +3,8 @@ package config
 import "errors"
 
 var (
-	ErrVariableNotFound = errors.New("variable not found")
-	ErrInvalidValue     = errors.New("invalid value")
-	ErrUnknowType       = errors.New("unknow type")
-	ErrInitFactory      = errors.New("init factory")
+	ErrValueNotFound = errors.New("value not found")
+	ErrInvalidValue  = errors.New("invalid value")
+	ErrUnknowType    = errors.New("unknow type")
+	ErrInitFactory   = errors.New("init factory")
 )
diff --git a/go.mod b/go.mod
index 824d50a..18dcf20 100644
--- a/go.mod
+++ b/go.mod
@@ -1,11 +1,11 @@
 module gitoa.ru/go-4devs/config
 
-go 1.16
+go 1.18
 
 require (
 	github.com/hashicorp/vault/api v1.1.0
+	github.com/iancoleman/strcase v0.3.0
 	github.com/pelletier/go-toml v1.9.0
-	github.com/smartystreets/goconvey v1.6.4 // indirect
 	github.com/stretchr/testify v1.7.0
 	github.com/tidwall/gjson v1.7.5
 	go.etcd.io/etcd/api/v3 v3.5.0-alpha.0
@@ -13,3 +13,40 @@ require (
 	gopkg.in/ini.v1 v1.62.0
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
 )
+
+require (
+	github.com/coreos/go-semver v0.3.0 // indirect
+	github.com/coreos/go-systemd/v22 v22.1.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/gogo/protobuf v1.3.1 // indirect
+	github.com/golang/protobuf v1.3.5 // indirect
+	github.com/golang/snappy v0.0.1 // indirect
+	github.com/hashicorp/errwrap v1.0.0 // indirect
+	github.com/hashicorp/go-cleanhttp v0.5.1 // indirect
+	github.com/hashicorp/go-multierror v1.1.0 // indirect
+	github.com/hashicorp/go-retryablehttp v0.6.6 // indirect
+	github.com/hashicorp/go-rootcerts v1.0.2 // indirect
+	github.com/hashicorp/go-sockaddr v1.0.2 // indirect
+	github.com/hashicorp/hcl v1.0.0 // indirect
+	github.com/hashicorp/vault/sdk v0.1.14-0.20200519221838-e0cfd64bc267 // indirect
+	github.com/mitchellh/go-homedir v1.1.0 // indirect
+	github.com/mitchellh/mapstructure v1.3.2 // indirect
+	github.com/pierrec/lz4 v2.0.5+incompatible // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/ryanuber/go-glob v1.0.0 // indirect
+	github.com/smartystreets/goconvey v1.6.4 // indirect
+	github.com/tidwall/match v1.0.3 // indirect
+	github.com/tidwall/pretty v1.1.0 // indirect
+	go.etcd.io/etcd/pkg/v3 v3.5.0-alpha.0 // indirect
+	go.uber.org/atomic v1.6.0 // indirect
+	go.uber.org/multierr v1.5.0 // indirect
+	go.uber.org/zap v1.16.0 // indirect
+	golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529 // indirect
+	golang.org/x/net v0.0.0-20200602114024-627f9648deb9 // indirect
+	golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect
+	golang.org/x/text v0.3.0 // indirect
+	golang.org/x/time v0.0.0-20200416051211-89c76fbcd5d1 // indirect
+	google.golang.org/genproto v0.0.0-20200513103714-09dca8ec2884 // indirect
+	google.golang.org/grpc v1.32.0 // indirect
+	gopkg.in/square/go-jose.v2 v2.5.1 // indirect
+)
diff --git a/go.sum b/go.sum
index 21c49ad..2cead0e 100644
--- a/go.sum
+++ b/go.sum
@@ -106,6 +106,8 @@ github.com/hashicorp/vault/api v1.1.0/go.mod h1:R3Umvhlxi2TN7Ex2hzOowyeNb+SfbVWI
 github.com/hashicorp/vault/sdk v0.1.14-0.20200519221838-e0cfd64bc267 h1:e1ok06zGrWJW91rzRroyl5nRNqraaBe4d5hiKcVZuHM=
 github.com/hashicorp/vault/sdk v0.1.14-0.20200519221838-e0cfd64bc267/go.mod h1:WX57W2PwkrOPQ6rVQk+dy5/htHIaB4aBM70EwKThu10=
 github.com/hashicorp/yamux v0.0.0-20180604194846-3520598351bb/go.mod h1:+NfK9FKeTrX5uv1uIXGdwYDTeHna2qgaIlx54MXqjAM=
+github.com/iancoleman/strcase v0.3.0 h1:nTXanmYxhfFAMjZL34Ov6gkzEsSJZ5DbhxWjvSASxEI=
+github.com/iancoleman/strcase v0.3.0/go.mod h1:iwCmte+B7n89clKwxIoIXy/HfoL7AsD47ZCWhYzw7ho=
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
 github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
@@ -257,8 +259,9 @@ golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200122134326-e047566fdf82/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634 h1:bNEHhJCnrwMKNMmOx3yAynp5vs5/gRy+XWFtZFu7NBM=
 golang.org/x/sys v0.0.0-20201009025420-dfb3f7c4e634/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 h1:0A+M6Uqn+Eje4kHMK80dtF3JCXC4ykBgQG4Fe06QRhQ=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/time v0.0.0-20200416051211-89c76fbcd5d1 h1:NusfzzA6yGQ+ua51ck7E3omNUX/JuqbFSaRGqU8CcLI=
diff --git a/provider.go b/provider.go
index 9b1ffff..d7fa9c0 100644
--- a/provider.go
+++ b/provider.go
@@ -3,17 +3,18 @@ package config
 import "context"
 
 type Provider interface {
-	Read(ctx context.Context, key Key) (Variable, error)
+	Value(ctx context.Context, path ...string) (Value, error)
 }
 
-type WatchCallback func(ctx context.Context, oldVar, newVar Variable)
-
-type WatchProvider interface {
-	Watch(ctx context.Context, key Key, callback WatchCallback) error
+type NamedProvider interface {
+	Name() string
+	Provider
 }
 
-type ReadConfig interface {
-	Value(ctx context.Context, name string) (Value, error)
+type WatchCallback func(ctx context.Context, oldVar, newVar Value)
+
+type WatchProvider interface {
+	Watch(ctx context.Context, callback WatchCallback, path ...string) error
 }
 
-type Factory func(ctx context.Context, cfg ReadConfig) (Provider, error)
+type Factory func(ctx context.Context, cfg Provider) (Provider, error)
diff --git a/provider/arg/provider.go b/provider/arg/provider.go
index e106f05..620ea8d 100644
--- a/provider/arg/provider.go
+++ b/provider/arg/provider.go
@@ -7,23 +7,27 @@ import (
 	"strings"
 
 	"gitoa.ru/go-4devs/config"
-	"gitoa.ru/go-4devs/config/key"
 	"gitoa.ru/go-4devs/config/value"
 	"gopkg.in/yaml.v3"
 )
 
+const Name = "arg"
+
 var _ config.Provider = (*Provider)(nil)
 
 type Option func(*Provider)
 
-func WithKeyFactory(factory config.KeyFactory) Option {
+func WithKeyFactory(factory func(s ...string) string) Option {
 	return func(p *Provider) { p.key = factory }
 }
 
 func New(opts ...Option) *Provider {
 	prov := Provider{
-		key:  key.Name,
+		key: func(s ...string) string {
+			return strings.Join(s, "-")
+		},
 		args: make(map[string][]string, len(os.Args[1:])),
+		name: Name,
 	}
 
 	for _, opt := range opts {
@@ -35,7 +39,8 @@ func New(opts ...Option) *Provider {
 
 type Provider struct {
 	args map[string][]string
-	key  config.KeyFactory
+	key  func(...string) string
+	name string
 }
 
 // nolint: cyclop
@@ -98,45 +103,29 @@ func (p *Provider) parse() error {
 }
 
 func (p *Provider) Name() string {
-	return "arg"
-}
-
-func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
-	return p.key(ctx, key) != ""
+	return p.name
 }
 
-func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
+func (p *Provider) Value(ctx context.Context, path ...string) (config.Value, error) {
 	if err := p.parse(); err != nil {
-		return config.Variable{
-			Name:     "",
-			Value:    nil,
-			Provider: p.Name(),
-		}, err
+		return nil, err
 	}
 
-	name := p.key(ctx, key)
+	name := p.key(path...)
 	if val, ok := p.args[name]; ok {
 		switch {
 		case len(val) == 1:
-			return config.Variable{
-				Name:     name,
-				Provider: p.Name(),
-				Value:    value.JString(val[0]),
-			}, nil
+			return value.JString(val[0]), nil
 		default:
 			var yNode yaml.Node
 
 			if err := yaml.Unmarshal([]byte("["+strings.Join(val, ",")+"]"), &yNode); err != nil {
-				return config.Variable{}, fmt.Errorf("arg: failed unmarshal yaml:%w", err)
+				return nil, fmt.Errorf("arg: failed unmarshal yaml:%w", err)
 			}
 
-			return config.Variable{
-				Name:     name,
-				Provider: p.Name(),
-				Value:    value.Decode(yNode.Decode),
-			}, nil
+			return value.Decode(yNode.Decode), nil
 		}
 	}
 
-	return config.Variable{}, fmt.Errorf("%w: %s", config.ErrVariableNotFound, name)
+	return nil, fmt.Errorf("%s:%w", p.Name(), config.ErrValueNotFound)
 }
diff --git a/provider/arg/provider_test.go b/provider/arg/provider_test.go
index 44216a5..a27cf2e 100644
--- a/provider/arg/provider_test.go
+++ b/provider/arg/provider_test.go
@@ -31,15 +31,15 @@ func TestProvider(t *testing.T) {
 		"--end-after=2008-01-02T15:04:05+03:00",
 	}
 	read := []test.Read{
-		test.NewRead("listen", 8080),
-		test.NewRead("config", "config.hcl"),
-		test.NewRead("start-at", test.Time("2010-01-02T15:04:05Z")),
-		test.NewReadUnmarshal("url", &[]string{"http://4devs.io", "https://4devs.io"}, &[]string{}),
-		test.NewReadUnmarshal("timeout", &[]time.Duration{time.Minute, time.Hour}, &[]time.Duration{}),
-		test.NewReadUnmarshal("end-after", &[]time.Time{
+		test.NewRead(8080, "listen"),
+		test.NewRead("config.hcl", "config"),
+		test.NewRead(test.Time("2010-01-02T15:04:05Z"), "start-at"),
+		test.NewReadUnmarshal(&[]string{"http://4devs.io", "https://4devs.io"}, &[]string{}, "url"),
+		test.NewReadUnmarshal(&[]time.Duration{time.Minute, time.Hour}, &[]time.Duration{}, "timeout"),
+		test.NewReadUnmarshal(&[]time.Time{
 			test.Time("2009-01-02T15:04:05Z"),
 			test.Time("2008-01-02T15:04:05+03:00"),
-		}, &[]time.Time{}),
+		}, &[]time.Time{}, "end-after"),
 	}
 
 	prov := arg.New()
diff --git a/provider/env/provider.go b/provider/env/provider.go
index e55520a..b287b34 100644
--- a/provider/env/provider.go
+++ b/provider/env/provider.go
@@ -2,27 +2,30 @@ package env
 
 import (
 	"context"
+	"fmt"
 	"os"
 	"strings"
 
 	"gitoa.ru/go-4devs/config"
-	"gitoa.ru/go-4devs/config/key"
 	"gitoa.ru/go-4devs/config/value"
 )
 
+const Name = "env"
+
 var _ config.Provider = (*Provider)(nil)
 
 type Option func(*Provider)
 
-func WithKeyFactory(factory config.KeyFactory) Option {
+func WithKeyFactory(factory func(...string) string) Option {
 	return func(p *Provider) { p.key = factory }
 }
 
-func New(opts ...Option) *Provider {
+func New(namespace, appName string, opts ...Option) *Provider {
 	provider := Provider{
-		key: func(ctx context.Context, k config.Key) string {
-			return strings.ToUpper(key.NsAppName("_")(ctx, k))
+		key: func(path ...string) string {
+			return strings.ToUpper(strings.Join(path, "_"))
 		},
+		prefix: strings.ToUpper(namespace + "_" + appName + "_"),
 	}
 
 	for _, opt := range opts {
@@ -33,26 +36,20 @@ func New(opts ...Option) *Provider {
 }
 
 type Provider struct {
-	key config.KeyFactory
+	key    func(...string) string
+	name   string
+	prefix string
 }
 
 func (p *Provider) Name() string {
-	return "env"
-}
-
-func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
-	return p.key(ctx, key) != ""
+	return p.name
 }
 
-func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
-	name := p.key(ctx, key)
+func (p *Provider) Value(ctx context.Context, path ...string) (config.Value, error) {
+	name := p.prefix + p.key(path...)
 	if val, ok := os.LookupEnv(name); ok {
-		return config.Variable{
-			Name:     name,
-			Provider: p.Name(),
-			Value:    value.JString(val),
-		}, nil
+		return value.JString(val), nil
 	}
 
-	return config.Variable{}, config.ErrVariableNotFound
+	return nil, fmt.Errorf("%v:%w", p.Name(), config.ErrValueNotFound)
 }
diff --git a/provider/env/provider_test.go b/provider/env/provider_test.go
index 4096718..501f86a 100644
--- a/provider/env/provider_test.go
+++ b/provider/env/provider_test.go
@@ -14,11 +14,11 @@ func TestProvider(t *testing.T) {
 	os.Setenv("FDEVS_CONFIG_DSN", test.DSN)
 	os.Setenv("FDEVS_CONFIG_PORT", "8080")
 
-	provider := env.New()
+	provider := env.New("fdevs", "config")
 
 	read := []test.Read{
-		test.NewRead("dsn", test.DSN),
-		test.NewRead("port", 8080),
+		test.NewRead(test.DSN, "dsn"),
+		test.NewRead(8080, "port"),
 	}
 	test.Run(t, provider, read)
 }
diff --git a/provider/etcd/provider.go b/provider/etcd/provider.go
index 91d187d..5e2a848 100644
--- a/provider/etcd/provider.go
+++ b/provider/etcd/provider.go
@@ -3,14 +3,19 @@ package etcd
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"gitoa.ru/go-4devs/config"
-	"gitoa.ru/go-4devs/config/key"
 	"gitoa.ru/go-4devs/config/value"
 	pb "go.etcd.io/etcd/api/v3/mvccpb"
 	client "go.etcd.io/etcd/client/v3"
 )
 
+const (
+	Name      = "etcd"
+	Separator = "/"
+)
+
 var (
 	_ config.Provider      = (*Provider)(nil)
 	_ config.WatchProvider = (*Provider)(nil)
@@ -21,10 +26,14 @@ type Client interface {
 	client.Watcher
 }
 
-func NewProvider(client Client) *Provider {
+func NewProvider(namespace, appName string, client Client) *Provider {
 	p := Provider{
 		client: client,
-		key:    key.NsAppName("/"),
+		key: func(s ...string) string {
+			return strings.Join(s, Separator)
+		},
+		name:   Name,
+		prefix: namespace + Separator + appName,
 	}
 
 	return &p
@@ -32,34 +41,35 @@ func NewProvider(client Client) *Provider {
 
 type Provider struct {
 	client Client
-	key    config.KeyFactory
-}
-
-func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
-	return p.key(ctx, key) != ""
+	key    func(...string) string
+	name   string
+	prefix string
 }
 
 func (p *Provider) Name() string {
-	return "etcd"
+	return p.name
+}
+func (p *Provider) Key(s []string) string {
+	return p.prefix + Separator + p.key(s...)
 }
 
-func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
-	name := p.key(ctx, key)
+func (p *Provider) Value(ctx context.Context, path ...string) (config.Value, error) {
+	name := p.Key(path)
 
 	resp, err := p.client.Get(ctx, name, client.WithPrefix())
 	if err != nil {
-		return config.Variable{}, fmt.Errorf("%w: key:%s, prov:%s", err, name, p.Name())
+		return nil, fmt.Errorf("%w: key:%s, prov:%s", err, name, p.Name())
 	}
 
 	val, err := p.resolve(name, resp.Kvs)
 	if err != nil {
-		return config.Variable{}, fmt.Errorf("%w: key:%s, prov:%s", err, name, p.Name())
+		return nil, fmt.Errorf("%w: key:%s, prov:%s", err, name, p.Name())
 	}
 
 	return val, nil
 }
 
-func (p *Provider) Watch(ctx context.Context, key config.Key, callback config.WatchCallback) error {
+func (p *Provider) Watch(ctx context.Context, callback config.WatchCallback, path ...string) error {
 	go func(ctx context.Context, key string, callback config.WatchCallback) {
 		watch := p.client.Watch(ctx, key, client.WithPrevKV(), client.WithPrefix())
 		for w := range watch {
@@ -70,7 +80,7 @@ func (p *Provider) Watch(ctx context.Context, key config.Key, callback config.Wa
 				callback(ctx, oldVar, newVar)
 			}
 		}
-	}(ctx, p.key(ctx, key), callback)
+	}(ctx, p.Key(path), callback)
 
 	return nil
 }
@@ -87,23 +97,15 @@ func (p *Provider) getEventKvs(events []*client.Event) ([]*pb.KeyValue, []*pb.Ke
 	return kvs, old
 }
 
-func (p *Provider) resolve(key string, kvs []*pb.KeyValue) (config.Variable, error) {
+func (p *Provider) resolve(key string, kvs []*pb.KeyValue) (config.Value, error) {
 	for _, kv := range kvs {
 		switch {
 		case kv == nil:
-			return config.Variable{
-				Name:     key,
-				Provider: p.Name(),
-				Value:    nil,
-			}, nil
+			return nil, nil
 		case string(kv.Key) == key:
-			return config.Variable{
-				Value:    value.JBytes(kv.Value),
-				Name:     key,
-				Provider: p.Name(),
-			}, nil
+			return value.JBytes(kv.Value), nil
 		}
 	}
 
-	return config.Variable{}, fmt.Errorf("%w: name %s", config.ErrVariableNotFound, key)
+	return nil, fmt.Errorf("%w: name %s", config.ErrValueNotFound, key)
 }
diff --git a/provider/etcd/provider_test.go b/provider/etcd/provider_test.go
index c547c71..82021e9 100644
--- a/provider/etcd/provider_test.go
+++ b/provider/etcd/provider_test.go
@@ -23,17 +23,17 @@ func TestProvider(t *testing.T) {
 	et, err := test.NewEtcd(ctx)
 	require.NoError(t, err)
 
-	provider := etcd.NewProvider(et)
+	provider := etcd.NewProvider("fdevs", "config", et)
 	read := []test.Read{
-		test.NewRead("db_dsn", test.DSN),
-		test.NewRead("duration", 12*time.Minute),
-		test.NewRead("port", 8080),
-		test.NewRead("maintain", true),
-		test.NewRead("start_at", test.Time("2020-01-02T15:04:05Z")),
-		test.NewRead("percent", .064),
-		test.NewRead("count", uint(2020)),
-		test.NewRead("int64", int64(2021)),
-		test.NewRead("uint64", int64(2022)),
+		test.NewRead(test.DSN, "db_dsn"),
+		test.NewRead(12*time.Minute, "duration"),
+		test.NewRead(8080, "port"),
+		test.NewRead(true, "maintain"),
+		test.NewRead(test.Time("2020-01-02T15:04:05Z"), "start_at"),
+		test.NewRead(.064, "percent"),
+		test.NewRead(uint(2020), "count"),
+		test.NewRead(int64(2021), "int64"),
+		test.NewRead(int64(2022), "uint64"),
 		test.NewReadConfig("config"),
 	}
 	test.Run(t, provider, read)
@@ -49,11 +49,7 @@ func TestWatcher(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	key := config.Key{
-		AppName:   "config",
-		Namespace: "fdevs",
-		Name:      "test_watch",
-	}
+	key := "test_watch"
 
 	et, err := test.NewEtcd(ctx)
 	require.NoError(t, err)
@@ -65,24 +61,24 @@ func TestWatcher(t *testing.T) {
 
 	var cnt, cnt2 int32
 
-	prov := etcd.NewProvider(et)
+	prov := etcd.NewProvider("fdevs", "config", et)
 	wg := sync.WaitGroup{}
 	wg.Add(6)
 
-	watch := func(cnt *int32) func(ctx context.Context, oldVar, newVar config.Variable) {
-		return func(ctx context.Context, oldVar, newVar config.Variable) {
+	watch := func(cnt *int32) func(ctx context.Context, oldVar, newVar config.Value) {
+		return func(ctx context.Context, oldVar, newVar config.Value) {
 			switch *cnt {
 			case 0:
-				assert.Equal(t, value(*cnt), newVar.Value.String())
-				assert.Nil(t, oldVar.Value)
+				assert.Equal(t, value(*cnt), newVar.String())
+				assert.Nil(t, oldVar)
 			case 1:
-				assert.Equal(t, value(*cnt), newVar.Value.String())
-				assert.Equal(t, value(*cnt-1), oldVar.Value.String())
+				assert.Equal(t, value(*cnt), newVar.String())
+				assert.Equal(t, value(*cnt-1), oldVar.String())
 			case 2:
-				_, perr := newVar.Value.ParseString()
+				_, perr := newVar.ParseString()
 				assert.NoError(t, perr)
-				assert.Equal(t, "", newVar.Value.String())
-				assert.Equal(t, value(*cnt-1), oldVar.Value.String())
+				assert.Equal(t, "", newVar.String())
+				assert.Equal(t, value(*cnt-1), oldVar.String())
 			default:
 				assert.Fail(t, "unexpected watch")
 			}
@@ -92,8 +88,8 @@ func TestWatcher(t *testing.T) {
 		}
 	}
 
-	err = prov.Watch(ctx, key, watch(&cnt))
-	err = prov.Watch(ctx, key, watch(&cnt2))
+	err = prov.Watch(ctx, watch(&cnt), key)
+	err = prov.Watch(ctx, watch(&cnt2), key)
 	require.NoError(t, err)
 
 	time.AfterFunc(time.Second, func() {
diff --git a/provider/ini/provider.go b/provider/ini/provider.go
index e06c15b..b7b048c 100644
--- a/provider/ini/provider.go
+++ b/provider/ini/provider.go
@@ -10,55 +10,49 @@ import (
 	"gopkg.in/ini.v1"
 )
 
+const (
+	Name      = "ini"
+	Separator = "."
+)
+
 var _ config.Provider = (*Provider)(nil)
 
 func New(data *ini.File) *Provider {
-	const nameParts = 2
-
 	return &Provider{
 		data: data,
-		resolve: func(ctx context.Context, key config.Key) (string, string) {
-			keys := strings.SplitN(key.Name, "/", nameParts)
-			if len(keys) == 1 {
-				return "", keys[0]
+		resolve: func(path []string) (string, string) {
+			if len(path) == 1 {
+				return "", path[0]
 			}
 
-			return keys[0], keys[1]
+			return strings.Join(path[:len(path)-1], Separator), strings.ToUpper(path[len(path)-1])
 		},
+		name: Name,
 	}
 }
 
 type Provider struct {
 	data    *ini.File
-	resolve func(ctx context.Context, key config.Key) (string, string)
-}
-
-func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
-	section, name := p.resolve(ctx, key)
-
-	return section != "" && name != ""
+	resolve func(path []string) (string, string)
+	name    string
 }
 
 func (p *Provider) Name() string {
-	return "ini"
+	return p.name
 }
 
-func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
-	section, name := p.resolve(ctx, key)
+func (p *Provider) Value(ctx context.Context, path ...string) (config.Value, error) {
+	section, name := p.resolve(path)
 
 	iniSection, err := p.data.GetSection(section)
 	if err != nil {
-		return config.Variable{}, fmt.Errorf("%w: %s: %w", config.ErrVariableNotFound, p.Name(), err)
+		return nil, fmt.Errorf("%w: %s: %w", config.ErrValueNotFound, p.Name(), err)
 	}
 
 	iniKey, err := iniSection.GetKey(name)
 	if err != nil {
-		return config.Variable{}, fmt.Errorf("%w: %s: %w", config.ErrVariableNotFound, p.Name(), err)
+		return nil, fmt.Errorf("%w: %s: %w", config.ErrValueNotFound, p.Name(), err)
 	}
 
-	return config.Variable{
-		Name:     section + ":" + name,
-		Provider: p.Name(),
-		Value:    value.JString(iniKey.String()),
-	}, nil
+	return value.JString(iniKey.String()), nil
 }
diff --git a/provider/ini/provider_test.go b/provider/ini/provider_test.go
index 3d1572d..2a74152 100644
--- a/provider/ini/provider_test.go
+++ b/provider/ini/provider_test.go
@@ -14,13 +14,13 @@ func TestProvider(t *testing.T) {
 	file := test.NewINI()
 
 	read := []test.Read{
-		test.NewRead("project/PROJECT_BOARD_BASIC_KANBAN_TYPE", "To Do, In Progress, Done"),
-		test.NewRead("repository.editor/PREVIEWABLE_FILE_MODES", "markdown"),
-		test.NewRead("server/LOCAL_ROOT_URL", "http://0.0.0.0:3000/"),
-		test.NewRead("server/LFS_HTTP_AUTH_EXPIRY", 20*time.Minute),
-		test.NewRead("repository.pull-request/DEFAULT_MERGE_MESSAGE_SIZE", 5120),
-		test.NewRead("ui/SHOW_USER_EMAIL", true),
-		test.NewRead("cors/ENABLED", false),
+		test.NewRead("To Do, In Progress, Done", "project", "PROJECT_BOARD_BASIC_KANBAN_TYPE"),
+		test.NewRead("markdown", "repository.editor", "PREVIEWABLE_FILE_MODES"),
+		test.NewRead("http://0.0.0.0:3000/", "server", "LOCAL_ROOT_URL"),
+		test.NewRead(20*time.Minute, "server", "LFS_HTTP_AUTH_EXPIRY"),
+		test.NewRead(5120, "repository.pull-request", "DEFAULT_MERGE_MESSAGE_SIZE"),
+		test.NewRead(true, "ui", "SHOW_USER_EMAIL"),
+		test.NewRead(false, "cors", "enabled"),
 	}
 
 	prov := ini.New(file)
diff --git a/provider/json/provider.go b/provider/json/provider.go
index 13d1647..69eae81 100644
--- a/provider/json/provider.go
+++ b/provider/json/provider.go
@@ -3,20 +3,27 @@ package json
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/tidwall/gjson"
 	"gitoa.ru/go-4devs/config"
-	"gitoa.ru/go-4devs/config/key"
 	"gitoa.ru/go-4devs/config/value"
 )
 
+const (
+	Name      = "json"
+	Separator = "."
+)
+
 var _ config.Provider = (*Provider)(nil)
 
 func New(json []byte, opts ...Option) *Provider {
 	provider := Provider{
-		key:  key.Name,
+		key: func(s ...string) string {
+			return strings.Join(s, Separator)
+		},
 		data: json,
 	}
 
@@ -28,7 +35,7 @@ func New(json []byte, opts ...Option) *Provider {
 }
 
 func NewFile(path string, opts ...Option) (*Provider, error) {
-	file, err := ioutil.ReadFile(filepath.Clean(path))
+	file, err := os.ReadFile(filepath.Clean(path))
 	if err != nil {
 		return nil, fmt.Errorf("%w: unable to read config file %#q: file not found or unreadable", err, path)
 	}
@@ -40,27 +47,19 @@ type Option func(*Provider)
 
 type Provider struct {
 	data []byte
-	key  config.KeyFactory
-}
-
-func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
-	return p.key(ctx, key) != ""
+	key  func(...string) string
+	name string
 }
 
 func (p *Provider) Name() string {
-	return "json"
+	return p.name
 }
 
-func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
-	path := p.key(ctx, key)
-
-	if val := gjson.GetBytes(p.data, path); val.Exists() {
-		return config.Variable{
-			Name:     path,
-			Provider: p.Name(),
-			Value:    value.JString(val.String()),
-		}, nil
+func (p *Provider) Value(ctx context.Context, path ...string) (config.Value, error) {
+	key := p.key(path...)
+	if val := gjson.GetBytes(p.data, key); val.Exists() {
+		return value.JString(val.String()), nil
 	}
 
-	return config.Variable{}, config.ErrVariableNotFound
+	return nil, fmt.Errorf("%v:%w", p.Name(), config.ErrValueNotFound)
 }
diff --git a/provider/json/provider_test.go b/provider/json/provider_test.go
index c5fa00c..68457c2 100644
--- a/provider/json/provider_test.go
+++ b/provider/json/provider_test.go
@@ -16,11 +16,11 @@ func TestProvider(t *testing.T) {
 	prov := provider.New(js)
 	sl := []string{}
 	read := []test.Read{
-		test.NewRead("app.name.title", "config title"),
-		test.NewRead("app.name.timeout", time.Minute),
-		test.NewReadUnmarshal("app.name.var", &[]string{"name"}, &sl),
+		test.NewRead("config title", "app.name.title"),
+		test.NewRead(time.Minute, "app.name.timeout"),
+		test.NewReadUnmarshal(&[]string{"name"}, &sl, "app.name.var"),
 		test.NewReadConfig("cfg"),
-		test.NewRead("app.name.success", true),
+		test.NewRead(true, "app", "name", "success"),
 	}
 
 	test.Run(t, prov, read)
diff --git a/provider/toml/provider.go b/provider/toml/provider.go
index 6129413..073aa8b 100644
--- a/provider/toml/provider.go
+++ b/provider/toml/provider.go
@@ -3,13 +3,18 @@ package toml
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"github.com/pelletier/go-toml"
 	"gitoa.ru/go-4devs/config"
-	"gitoa.ru/go-4devs/config/key"
 	"gitoa.ru/go-4devs/config/value"
 )
 
+const (
+	Name      = "toml"
+	Separator = "."
+)
+
 var _ config.Provider = (*Provider)(nil)
 
 func NewFile(file string, opts ...Option) (*Provider, error) {
@@ -26,7 +31,9 @@ type Option func(*Provider)
 func configure(tree *toml.Tree, opts ...Option) *Provider {
 	prov := &Provider{
 		tree: tree,
-		key:  key.Name,
+		key: func(s []string) string {
+			return strings.Join(s, Separator)
+		},
 	}
 
 	for _, opt := range opts {
@@ -47,25 +54,18 @@ func New(data []byte, opts ...Option) (*Provider, error) {
 
 type Provider struct {
 	tree *toml.Tree
-	key  config.KeyFactory
-}
-
-func (p *Provider) IsSupport(ctx context.Context, key config.Key) bool {
-	return p.key(ctx, key) != ""
+	key  func([]string) string
+	name string
 }
 
 func (p *Provider) Name() string {
-	return "toml"
+	return p.name
 }
 
-func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
-	if k := p.key(ctx, key); p.tree.Has(k) {
-		return config.Variable{
-			Name:     k,
-			Provider: p.Name(),
-			Value:    Value{Value: value.Value{Val: p.tree.Get(k)}},
-		}, nil
+func (p *Provider) Value(ctx context.Context, path ...string) (config.Value, error) {
+	if k := p.key(path); p.tree.Has(k) {
+		return Value{Value: value.Value{Val: p.tree.Get(k)}}, nil
 	}
 
-	return config.Variable{}, config.ErrVariableNotFound
+	return nil, config.ErrValueNotFound
 }
diff --git a/provider/toml/provider_test.go b/provider/toml/provider_test.go
index 98cfe02..89c3abe 100644
--- a/provider/toml/provider_test.go
+++ b/provider/toml/provider_test.go
@@ -17,12 +17,12 @@ func TestProvider(t *testing.T) {
 	m := []int{}
 
 	read := []test.Read{
-		test.NewRead("database.server", "192.168.1.1"),
-		test.NewRead("title", "TOML Example"),
-		test.NewRead("servers.alpha.ip", "10.0.0.1"),
-		test.NewRead("database.enabled", true),
-		test.NewRead("database.connection_max", 5000),
-		test.NewReadUnmarshal("database.ports", &[]int{8001, 8001, 8002}, &m),
+		test.NewRead("192.168.1.1", "database.server"),
+		test.NewRead("TOML Example", "title"),
+		test.NewRead("10.0.0.1", "servers.alpha.ip"),
+		test.NewRead(true, "database.enabled"),
+		test.NewRead(5000, "database.connection_max"),
+		test.NewReadUnmarshal(&[]int{8001, 8001, 8002}, &m, "database", "ports"),
 	}
 
 	test.Run(t, prov, read)
diff --git a/provider/vault/secret.go b/provider/vault/secret.go
index 0e56ce4..1d1a650 100644
--- a/provider/vault/secret.go
+++ b/provider/vault/secret.go
@@ -4,25 +4,42 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log"
+	"strings"
 
 	"github.com/hashicorp/vault/api"
 	"gitoa.ru/go-4devs/config"
-	"gitoa.ru/go-4devs/config/key"
 	"gitoa.ru/go-4devs/config/value"
 )
 
+const (
+	Name      = "vault"
+	Separator = "/"
+	Prefix    = "secret/data/"
+	ValueName = "value"
+)
+
 var _ config.Provider = (*SecretKV2)(nil)
 
 type SecretOption func(*SecretKV2)
 
-func WithSecretResolve(f func(context.Context, config.Key) (string, string)) SecretOption {
+func WithSecretResolve(f func(key []string) (string, string)) SecretOption {
 	return func(s *SecretKV2) { s.resolve = f }
 }
 
-func NewSecretKV2(client *api.Client, opts ...SecretOption) *SecretKV2 {
+func NewSecretKV2(namespace, appName string, client *api.Client, opts ...SecretOption) *SecretKV2 {
 	prov := SecretKV2{
-		client:  client,
-		resolve: key.LastIndexField(":", "value", key.PrefixName("secret/data/", key.NsAppName("/"))),
+		client: client,
+		resolve: func(key []string) (string, string) {
+			keysLen := len(key)
+			if keysLen == 1 {
+				return "", key[0]
+			}
+
+			return strings.Join(key[:keysLen-1], Separator), key[keysLen-1]
+		},
+		name:   Name,
+		prefix: Prefix + namespace + Separator + appName,
 	}
 
 	for _, opt := range opts {
@@ -34,57 +51,69 @@ func NewSecretKV2(client *api.Client, opts ...SecretOption) *SecretKV2 {
 
 type SecretKV2 struct {
 	client  *api.Client
-	resolve func(ctx context.Context, key config.Key) (string, string)
+	resolve func(key []string) (string, string)
+	name    string
+	prefix  string
 }
 
-func (p *SecretKV2) IsSupport(ctx context.Context, key config.Key) bool {
-	path, _ := p.resolve(ctx, key)
+func (p *SecretKV2) Name() string {
+	return p.name
+}
+func (p *SecretKV2) Key(in []string) (string, string) {
+	path, val := p.resolve(in)
+	if path == "" {
+		return p.prefix, val
+	}
 
-	return path != ""
+	return p.prefix + Separator + path, val
 }
+func (p *SecretKV2) read(path, key string) (*api.Secret, error) {
+	secret, err := p.client.Logical().Read(path)
+	if err != nil {
+		return nil, err
+	}
+	if secret == nil && key != ValueName {
+		return p.read(path+Separator+key, ValueName)
+	}
 
-func (p *SecretKV2) Name() string {
-	return "vault"
+	return secret, err
 }
 
-func (p *SecretKV2) Read(ctx context.Context, key config.Key) (config.Variable, error) {
-	path, field := p.resolve(ctx, key)
+func (p *SecretKV2) Value(ctx context.Context, key ...string) (config.Value, error) {
+	path, field := p.Key(key)
 
-	secret, err := p.client.Logical().Read(path)
+	secret, err := p.read(path, field)
 	if err != nil {
-		return config.Variable{}, fmt.Errorf("%w: path:%s, field:%s, provider:%s", err, path, field, p.Name())
+		return nil, fmt.Errorf("%w: path:%s, field:%s, provider:%s", err, path, field, p.Name())
 	}
 
 	if secret == nil || len(secret.Data) == 0 {
-		return config.Variable{}, fmt.Errorf("%w: path:%s, field:%s, provider:%s", config.ErrVariableNotFound, path, field, p.Name())
+		log.Println(secret == nil)
+		return nil, fmt.Errorf("%w: path:%s, field:%s, provider:%s", config.ErrValueNotFound, path, field, p.Name())
 	}
 
 	if len(secret.Warnings) > 0 {
-		return config.Variable{},
-			fmt.Errorf("%w: warn: %s, path:%s, field:%s, provider:%s", config.ErrVariableNotFound, secret.Warnings, path, field, p.Name())
+		return nil,
+			fmt.Errorf("%w: warn: %s, path:%s, field:%s, provider:%s", config.ErrValueNotFound, secret.Warnings, path, field, p.Name())
 	}
 
 	data, ok := secret.Data["data"].(map[string]interface{})
 	if !ok {
-		return config.Variable{}, fmt.Errorf("%w: path:%s, field:%s, provider:%s", config.ErrVariableNotFound, path, field, p.Name())
+		return nil, fmt.Errorf("%w: path:%s, field:%s, provider:%s", config.ErrValueNotFound, path, field, p.Name())
 	}
 
 	if val, ok := data[field]; ok {
-		return config.Variable{
-			Name:     path + field,
-			Provider: p.Name(),
-			Value:    value.JString(fmt.Sprint(val)),
-		}, nil
+		return value.JString(fmt.Sprint(val)), nil
+	}
+
+	if val, ok := data[ValueName]; ok {
+		return value.JString(fmt.Sprint(val)), nil
 	}
 
 	md, err := json.Marshal(data)
 	if err != nil {
-		return config.Variable{}, fmt.Errorf("%w: %w", config.ErrInvalidValue, err)
+		return nil, fmt.Errorf("%w: %w", config.ErrInvalidValue, err)
 	}
 
-	return config.Variable{
-		Name:     path + field,
-		Provider: p.Name(),
-		Value:    value.JBytes(md),
-	}, nil
+	return value.JBytes(md), nil
 }
diff --git a/provider/vault/secret_test.go b/provider/vault/secret_test.go
index 330286f..0501904 100644
--- a/provider/vault/secret_test.go
+++ b/provider/vault/secret_test.go
@@ -15,12 +15,12 @@ func TestProvider(t *testing.T) {
 	cl, err := test.NewVault()
 	require.NoError(t, err)
 
-	provider := vault.NewSecretKV2(cl)
+	provider := vault.NewSecretKV2("fdevs", "config", cl)
 
 	read := []test.Read{
 		test.NewReadConfig("database"),
-		test.NewRead("db:dsn", test.DSN),
-		test.NewRead("db:timeout", time.Minute),
+		test.NewRead(test.DSN, "db", "dsn"),
+		test.NewRead(time.Minute, "db", "timeout"),
 	}
 	test.Run(t, provider, read)
 }
diff --git a/provider/watcher/provider.go b/provider/watcher/provider.go
index fece95c..b821c3d 100644
--- a/provider/watcher/provider.go
+++ b/provider/watcher/provider.go
@@ -14,10 +14,10 @@ var (
 	_ config.WatchProvider = (*Provider)(nil)
 )
 
-func New(duration time.Duration, provider config.Provider, opts ...Option) *Provider {
+func New(duration time.Duration, provider config.NamedProvider, opts ...Option) *Provider {
 	prov := &Provider{
-		Provider: provider,
-		ticker:   time.NewTicker(duration),
+		NamedProvider: provider,
+		ticker:        time.NewTicker(duration),
 		logger: func(_ context.Context, msg string) {
 			log.Print(msg)
 		},
@@ -39,13 +39,13 @@ func WithLogger(l func(context.Context, string)) Option {
 type Option func(*Provider)
 
 type Provider struct {
-	config.Provider
+	config.NamedProvider
 	ticker *time.Ticker
 	logger func(context.Context, string)
 }
 
-func (p *Provider) Watch(ctx context.Context, key config.Key, callback config.WatchCallback) error {
-	oldVar, err := p.Provider.Read(ctx, key)
+func (p *Provider) Watch(ctx context.Context, callback config.WatchCallback, key ...string) error {
+	oldVar, err := p.NamedProvider.Value(ctx, key...)
 	if err != nil {
 		return fmt.Errorf("failed watch variable: %w", err)
 	}
@@ -54,7 +54,7 @@ func (p *Provider) Watch(ctx context.Context, key config.Key, callback config.Wa
 		for {
 			select {
 			case <-p.ticker.C:
-				newVar, err := p.Provider.Read(ctx, key)
+				newVar, err := p.NamedProvider.Value(ctx, key...)
 				if err != nil {
 					p.logger(ctx, err.Error())
 				} else if !newVar.IsEquals(oldVar) {
diff --git a/provider/watcher/provider_test.go b/provider/watcher/provider_test.go
index 47611c9..d4d089f 100644
--- a/provider/watcher/provider_test.go
+++ b/provider/watcher/provider_test.go
@@ -22,14 +22,10 @@ func (p *provider) Name() string {
 	return "test"
 }
 
-func (p *provider) Read(context.Context, config.Key) (config.Variable, error) {
+func (p *provider) Value(context.Context, ...string) (config.Value, error) {
 	p.cnt++
 
-	return config.Variable{
-		Name:     "tmpname",
-		Provider: p.Name(),
-		Value:    value.JString(fmt.Sprint(p.cnt)),
-	}, nil
+	return value.JString(fmt.Sprint(p.cnt)), nil
 }
 
 func TestWatcher(t *testing.T) {
@@ -46,11 +42,11 @@ func TestWatcher(t *testing.T) {
 
 	err := w.Watch(
 		ctx,
-		config.Key{Name: "tmpname"},
-		func(ctx context.Context, oldVar, newVar config.Variable) {
+		func(ctx context.Context, oldVar, newVar config.Value) {
 			atomic.AddInt32(&cnt, 1)
 			wg.Done()
 		},
+		"tmpname",
 	)
 	require.NoError(t, err)
 	wg.Wait()
diff --git a/provider/yaml/provider.go b/provider/yaml/provider.go
index 7e173a1..eefc5f0 100644
--- a/provider/yaml/provider.go
+++ b/provider/yaml/provider.go
@@ -4,22 +4,21 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io/ioutil"
-	"strings"
+	"os"
 
 	"gitoa.ru/go-4devs/config"
 	"gitoa.ru/go-4devs/config/value"
 	"gopkg.in/yaml.v3"
 )
 
-var _ config.Provider = (*Provider)(nil)
+const (
+	Name = "yaml"
+)
 
-func keyFactory(_ context.Context, key config.Key) []string {
-	return strings.Split(key.Name, "/")
-}
+var _ config.Provider = (*Provider)(nil)
 
 func NewFile(name string, opts ...Option) (*Provider, error) {
-	in, err := ioutil.ReadFile(name)
+	in, err := os.ReadFile(name)
 	if err != nil {
 		return nil, fmt.Errorf("yaml_file: read error: %w", err)
 	}
@@ -38,7 +37,7 @@ func New(yml []byte, opts ...Option) (*Provider, error) {
 
 func create(opts ...Option) *Provider {
 	prov := Provider{
-		key: keyFactory,
+		name: Name,
 	}
 
 	for _, opt := range opts {
@@ -52,22 +51,20 @@ type Option func(*Provider)
 
 type Provider struct {
 	data node
-	key  func(context.Context, config.Key) []string
+	name string
 }
 
 func (p *Provider) Name() string {
-	return "yaml"
+	return p.name
 }
 
-func (p *Provider) Read(ctx context.Context, key config.Key) (config.Variable, error) {
-	k := p.key(ctx, key)
+func (p *Provider) Value(_ context.Context, path ...string) (config.Value, error) {
 
-	return p.data.read(p.Name(), k)
+	return p.data.read(p.Name(), path)
 }
 
 func (p *Provider) With(data *yaml.Node) *Provider {
 	return &Provider{
-		key:  p.key,
 		data: node{Node: data},
 	}
 }
@@ -76,21 +73,17 @@ type node struct {
 	*yaml.Node
 }
 
-func (n *node) read(name string, keys []string) (config.Variable, error) {
+func (n *node) read(name string, keys []string) (config.Value, error) {
 	val, err := getData(n.Node.Content[0].Content, keys)
 	if err != nil {
-		if errors.Is(err, config.ErrVariableNotFound) {
-			return config.Variable{}, fmt.Errorf("%w: %s", config.ErrVariableNotFound, name)
+		if errors.Is(err, config.ErrValueNotFound) {
+			return nil, fmt.Errorf("%w: %s", config.ErrValueNotFound, name)
 		}
 
-		return config.Variable{}, fmt.Errorf("%w: %s", err, name)
+		return nil, fmt.Errorf("%w: %s", err, name)
 	}
 
-	return config.Variable{
-		Name:     strings.Join(keys, "."),
-		Provider: name,
-		Value:    value.Decode(val),
-	}, nil
+	return value.Decode(val), nil
 }
 
 func getData(node []*yaml.Node, keys []string) (func(interface{}) error, error) {
@@ -104,5 +97,5 @@ func getData(node []*yaml.Node, keys []string) (func(interface{}) error, error)
 		}
 	}
 
-	return nil, config.ErrVariableNotFound
+	return nil, config.ErrValueNotFound
 }
diff --git a/provider/yaml/provider_test.go b/provider/yaml/provider_test.go
index c4e970c..e5105db 100644
--- a/provider/yaml/provider_test.go
+++ b/provider/yaml/provider_test.go
@@ -16,9 +16,9 @@ func TestProvider(t *testing.T) {
 	require.Nil(t, err)
 
 	read := []test.Read{
-		test.NewRead("duration_var", 21*time.Minute),
-		test.NewRead("app/name/bool_var", true),
-		test.NewRead("time_var", test.Time("2020-01-02T15:04:05Z")),
+		test.NewRead(21*time.Minute, "duration_var"),
+		test.NewRead(true, "app", "name", "bool_var"),
+		test.NewRead(test.Time("2020-01-02T15:04:05Z"), "time_var"),
 		test.NewReadConfig("cfg"),
 	}
 
diff --git a/provider/yaml/watch.go b/provider/yaml/watch.go
index 2da862a..a88fc67 100644
--- a/provider/yaml/watch.go
+++ b/provider/yaml/watch.go
@@ -3,16 +3,19 @@ package yaml
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
+	"os"
 
 	"gitoa.ru/go-4devs/config"
 	"gopkg.in/yaml.v3"
 )
 
+const NameWatch = "yaml_watch"
+
 func NewWatch(name string, opts ...Option) *Watch {
 	f := Watch{
 		file: name,
 		prov: create(opts...),
+		name: NameWatch,
 	}
 
 	return &f
@@ -21,22 +24,23 @@ func NewWatch(name string, opts ...Option) *Watch {
 type Watch struct {
 	file string
 	prov *Provider
+	name string
 }
 
 func (p *Watch) Name() string {
-	return "yaml_watch"
+	return p.name
 }
 
-func (p *Watch) Read(ctx context.Context, key config.Key) (config.Variable, error) {
-	in, err := ioutil.ReadFile(p.file)
+func (p *Watch) Value(ctx context.Context, path ...string) (config.Value, error) {
+	in, err := os.ReadFile(p.file)
 	if err != nil {
-		return config.Variable{}, fmt.Errorf("yaml_file: read error: %w", err)
+		return nil, fmt.Errorf("yaml_file: read error: %w", err)
 	}
 
 	var yNode yaml.Node
 	if err = yaml.Unmarshal(in, &yNode); err != nil {
-		return config.Variable{}, fmt.Errorf("yaml_file: unmarshal error: %w", err)
+		return nil, fmt.Errorf("yaml_file: unmarshal error: %w", err)
 	}
 
-	return p.prov.With(&yNode).Read(ctx, key)
+	return p.prov.With(&yNode).Value(ctx, path...)
 }
diff --git a/test/provider_suite.go b/test/provider_suite.go
index 7635c79..c71ae92 100644
--- a/test/provider_suite.go
+++ b/test/provider_suite.go
@@ -35,7 +35,7 @@ type ProviderSuite struct {
 }
 
 type Read struct {
-	Key    config.Key
+	Key    []string
 	Assert func(t *testing.T, v config.Value)
 }
 
@@ -46,22 +46,18 @@ type Config struct {
 	Enabled  bool
 }
 
-func NewReadConfig(key string) Read {
+func NewReadConfig(key ...string) Read {
 	ex := &Config{
 		Duration: 21 * time.Minute,
 		Enabled:  true,
 	}
 
-	return NewReadUnmarshal(key, ex, &Config{})
+	return NewReadUnmarshal(ex, &Config{}, key...)
 }
 
-func NewReadUnmarshal(key string, expected, target interface{}) Read {
+func NewReadUnmarshal(expected, target interface{}, key ...string) Read {
 	return Read{
-		Key: config.Key{
-			Namespace: "fdevs",
-			AppName:   "config",
-			Name:      key,
-		},
+		Key: key,
 		Assert: func(t *testing.T, v config.Value) {
 			t.Helper()
 			require.NoErrorf(t, v.Unmarshal(target), "unmarshal")
@@ -77,13 +73,9 @@ func Time(value string) time.Time {
 }
 
 // nolint: cyclop
-func NewRead(key string, expected interface{}) Read {
+func NewRead(expected interface{}, key ...string) Read {
 	return Read{
-		Key: config.Key{
-			Namespace: "fdevs",
-			AppName:   "config",
-			Name:      key,
-		},
+		Key: key,
 		Assert: func(t *testing.T, v config.Value) {
 			t.Helper()
 			var (
@@ -134,9 +126,9 @@ func (ps *ProviderSuite) TestReadKeys() {
 	ctx := context.Background()
 
 	for _, read := range ps.read {
-		val, err := ps.provider.Read(ctx, read.Key)
-		require.NoError(ps.T(), err, read.Key.String())
-		read.Assert(ps.T(), val.Value)
+		val, err := ps.provider.Value(ctx, read.Key...)
+		require.NoError(ps.T(), err, read.Key)
+		read.Assert(ps.T(), val)
 	}
 }
 
diff --git a/value.go b/value.go
index 8d9e86e..26cd231 100644
--- a/value.go
+++ b/value.go
@@ -8,6 +8,7 @@ type Value interface {
 	ReadValue
 	ParseValue
 	UnmarshalValue
+	IsEquals(Value) bool
 }
 
 type UnmarshalValue interface {
diff --git a/value/decode.go b/value/decode.go
index 8258fda..eaf8a61 100644
--- a/value/decode.go
+++ b/value/decode.go
@@ -108,3 +108,7 @@ func (s Decode) Time() time.Time {
 
 	return in
 }
+
+func (s Decode) IsEquals(in config.Value) bool {
+	return s.String() == in.String()
+}
diff --git a/value/jbytes.go b/value/jbytes.go
index d500db3..051d637 100644
--- a/value/jbytes.go
+++ b/value/jbytes.go
@@ -110,3 +110,7 @@ func (s JBytes) Time() time.Time {
 
 	return in
 }
+
+func (s JBytes) IsEquals(in config.Value) bool {
+	return s.String() == in.String()
+}
diff --git a/value/jstring.go b/value/jstring.go
index fa80cb7..e9d752c 100644
--- a/value/jstring.go
+++ b/value/jstring.go
@@ -110,3 +110,7 @@ func (s JString) Time() time.Time {
 
 	return in
 }
+
+func (s JString) IsEquals(in config.Value) bool {
+	return s.String() == in.String()
+}
diff --git a/value/value.go b/value/value.go
index 727fd86..f2d5f79 100644
--- a/value/value.go
+++ b/value/value.go
@@ -156,3 +156,7 @@ func (s Value) ParseTime() (time.Time, error) {
 
 	return time.Time{}, config.ErrInvalidValue
 }
+
+func (s Value) IsEquals(in config.Value) bool {
+	return s.String() == in.String()
+}