diff --git a/config/config.go b/config/config.go
index 1b943b7..7e601a0 100644
--- a/config/config.go
+++ b/config/config.go
@@ -7,36 +7,73 @@ import (
 	lib "git.sr.ht/~cco/go-scopes"
 )
 
-type Cfg struct {
-	*BaseCfg
-	ConfigFormat string
+// default config
+
+type DefaultCfg = defcfg
+
+type defcfg struct {
+	name     string
+	actions  []lib.ActionConfig
+	children []lib.Config
 }
 
-func Start(ctx lib.Context) {
+func (cfg *defcfg) Name() string {
+	return cfg.name
 }
 
-// definitions
+func (cfg *defcfg) SetName(n string) {
+	cfg.name = n
+}
+
+func (cfg *defcfg) Actions() []lib.ActionConfig {
+	return cfg.actions
+}
+
+func (cfg *defcfg) AddAction(pattern string, specs ...lib.ActionSpec) {
+	act := ActionConfig(pattern, specs)
+	cfg.actions = append(cfg.actions, act)
+}
+
+func (cfg *defcfg) Children() []lib.Config {
+	return cfg.children
+}
+
+func (cfg *defcfg) Add(c ...lib.Config) {
+	cfg.children = append(cfg.children, c...)
+}
+
+func (cfg *defcfg) Starter() lib.StartProc {
+	return DefaultStart
+}
+
+func (cfg *defcfg) Step() lib.StepProc {
+	return DefaultStep
+}
+
+func (cfg *defcfg) MessageHandler() lib.MessageHandler {
+	return DefaultMsgHandler
+}
+
+func (cfg *defcfg) DoneHandler() lib.StepProc {
+	return DefaultDoneHandler
+}
+
+func Default(name string) lib.Config {
+	return &defcfg{
+		name: name,
+	}
+}
+
+// base config
 
 type BaseCfg = base
 
 type base struct {
-	name        string
+	*defcfg
 	starter     lib.StartProc
 	step        lib.StepProc
 	msgHandler  lib.MessageHandler
 	doneHandler lib.StepProc
-	actions     []lib.ActionConfig
-	children    []lib.Config
-}
-
-// lib.Config implementation
-
-func (cfg *base) Name() string {
-	return cfg.name
-}
-
-func (cfg *base) SetName(n string) {
-	cfg.name = n
 }
 
 func (cfg *base) Starter() lib.StartProc {
@@ -55,19 +92,6 @@ func (cfg *base) DoneHandler() lib.StepProc {
 	return cfg.doneHandler
 }
 
-func (cfg *base) Actions() []lib.ActionConfig {
-	return cfg.actions
-}
-
-func (cfg *base) Children() []lib.Config {
-	return cfg.children
-}
-
-func (cfg *base) Add(c ...lib.Config) lib.Config {
-	cfg.children = append(cfg.children, c...)
-	return cfg
-}
-
 // implementation-specific methods and functions
 
 func (cfg *base) WithStep(step lib.StepProc) *base {
@@ -85,24 +109,20 @@ func (cfg *base) WithDoneHandler(hdlr lib.StepProc) *base {
 	return cfg
 }
 
-func (cfg *base) AddAction(pattern string, specs ...lib.ActionSpec) lib.Config {
-	act := ActionConfig(pattern, specs)
-	cfg.actions = append(cfg.actions, act)
-	return cfg
-}
-
 func Base(name string, starter lib.StartProc) *base {
 	return &base{
-		name:        name,
+		defcfg: &defcfg{
+			name: name,
+		},
 		starter:     starter,
 		step:        DefaultStep,
 		msgHandler:  DefaultMsgHandler,
 		doneHandler: DefaultDoneHandler,
-		actions:     nil,
 	}
 }
 
 // will be set by core.init()
+var DefaultStart lib.StartProc
 var DefaultStep lib.StepProc
 var DefaultMsgHandler lib.MessageHandler
 var DefaultDoneHandler lib.StepProc
diff --git a/core/core.go b/core/core.go
index ce418ad..aefbc93 100644
--- a/core/core.go
+++ b/core/core.go
@@ -46,7 +46,8 @@ func HandleDone(ctx lib.Context) bool {
 }
 
 func init() {
-	config.DefaultStep = Step // avoid import cycle
+	config.DefaultStart = Start // avoid import cycle
+	config.DefaultStep = Step
 	config.DefaultMsgHandler = HandleMessage
 	config.DefaultDoneHandler = HandleDone
 }
diff --git a/examples/demo/etc/etc.go b/examples/demo/etc/etc.go
index 631e70b..c97897b 100644
--- a/examples/demo/etc/etc.go
+++ b/examples/demo/etc/etc.go
@@ -10,6 +10,7 @@ import (
 func Config() lib.Config {
 	ovr := Overrides().Use
 	b := config.Base
+
 	app_c := app.Cfg{
 		BaseCfg: b("dummy", app.Start),
 		Home:    ovr(".", HOME),
@@ -18,10 +19,7 @@ func Config() lib.Config {
 			Logfile: ovr("log/scopes.log", LOGFILE),
 		},
 	}
-	app_c.Add(config.Cfg{
-		BaseCfg:      b("config", config.Start),
-		ConfigFormat: "etc",
-	})
+
 	return &app_c
 }
 
diff --git a/matrix/matrix.go b/matrix/matrix.go
index b1e0919..c899bfd 100644
--- a/matrix/matrix.go
+++ b/matrix/matrix.go
@@ -3,15 +3,14 @@ package matrix
 import (
 	lib "git.sr.ht/~cco/go-scopes"
 	"git.sr.ht/~cco/go-scopes/config"
-	"git.sr.ht/~cco/go-scopes/core"
 	"git.sr.ht/~cco/go-scopes/core/action"
 	"git.sr.ht/~cco/go-scopes/core/message"
 )
 
-func Start(ctx lib.Context) {
-	cfg := ctx.Config()
+func DefaultConfig(name string) lib.Config {
+	cfg := config.Default(name)
 	cfg.AddAction("create", action.Base(create))
-	core.Start(ctx)
+	return cfg
 }
 
 func create(act lib.Action) bool {
@@ -24,7 +23,7 @@ func create(act lib.Action) bool {
 }
 
 func createCell(ctx lib.Context) lib.Context {
-	cfg := config.Base("", core.Start)
+	cfg := DefaultConfig("")
 	cctx := ctx.ChildContext(cfg)
 	cfg.Starter()(cctx)
 	return cctx
diff --git a/scopes.go b/scopes.go
index 64a0291..63f9723 100644
--- a/scopes.go
+++ b/scopes.go
@@ -103,9 +103,9 @@ type Config interface {
 	MessageHandler() MessageHandler
 	DoneHandler() StepProc
 	Actions() []ActionConfig
-	AddAction(string, ...ActionSpec) Config
+	AddAction(string, ...ActionSpec)
 	Children() []Config
-	Add(...Config) Config
+	Add(...Config)
 }
 
 type ActionConfig interface {
diff --git a/tests/core_test.go b/tests/core_test.go
index ce86a45..a25d2e1 100644
--- a/tests/core_test.go
+++ b/tests/core_test.go
@@ -71,9 +71,9 @@ func ActionTest(t *testing.T) {
 			return true
 		}
 	}
-	cfg := config.Base("testing", core.None).
-		AddAction("start", action.Base(hdlrGen("started"))).
-		AddAction("scopes|doit|task", action.Base(hdlrGen("done")))
+	cfg := config.Base("testing", core.None)
+	cfg.AddAction("start", action.Base(hdlrGen("started")))
+	cfg.AddAction("scopes|doit|task", action.Base(hdlrGen("done")))
 	ctx := context.AppContext(cfg)
 	lib.HandleMsg(ctx, message.SimpleMessage("start"))
 	t.AssertEqual(result.data, "started")
diff --git a/tests/etc/etc.go b/tests/etc/etc.go
index 3396982..ceaaa17 100644
--- a/tests/etc/etc.go
+++ b/tests/etc/etc.go
@@ -27,11 +27,6 @@ func Config() lib.Config {
 	}
 	app_c.AddAction("demo", action.Base(action.Forward, "test-receiver"))
 
-	config_c := &config.Cfg{
-		BaseCfg:      b("config", config.Start),
-		ConfigFormat: "etc",
-	}
-
 	server_c := &server.Cfg{
 		BaseCfg: b("server", server.Start),
 		Port:    ovr("8123", SERVER_PORT),
@@ -43,10 +38,10 @@ func Config() lib.Config {
 	}
 	test_client.AddAction("demo", action.Base(client.Send))
 
-	test_rcvr := b("test-receiver", core.Start).
-		AddAction("demo", action.Base(AH_Receiver))
+	test_rcvr := b("test-receiver", core.Start)
+	test_rcvr.AddAction("demo", action.Base(AH_Receiver))
 
-	app_c.Add(config_c, server_c, test_client, test_rcvr)
+	app_c.Add(server_c, test_client, test_rcvr)
 
 	return app_c
 }
diff --git a/tests/etc/etc_mx.go b/tests/etc/etc_mx.go
index 07efd7b..70dcfba 100644
--- a/tests/etc/etc_mx.go
+++ b/tests/etc/etc_mx.go
@@ -5,7 +5,6 @@ import (
 	"git.sr.ht/~cco/go-scopes/app"
 	"git.sr.ht/~cco/go-scopes/common/testing"
 	"git.sr.ht/~cco/go-scopes/config"
-	"git.sr.ht/~cco/go-scopes/core"
 	"git.sr.ht/~cco/go-scopes/core/action"
 	"git.sr.ht/~cco/go-scopes/logging"
 	"git.sr.ht/~cco/go-scopes/matrix"
@@ -23,10 +22,10 @@ func ConfigMx() lib.Config {
 	}
 	app_c.AddAction("demo", action.Base(action.Forward, "test-receiver"))
 
-	test_rcvr := b("test-receiver", core.Start).
-		AddAction("demo", action.Base(AH_MxReceiver))
+	test_rcvr := config.Default("test-receiver")
+	test_rcvr.AddAction("demo", action.Base(AH_MxReceiver))
 
-	cell_0 := b("cell-0", matrix.Start)
+	cell_0 := matrix.DefaultConfig("cell-0")
 
 	app_c.Add(cell_0, test_rcvr)
 
diff --git a/tests/matrix_test.go b/tests/matrix_test.go
index 855c7c1..979c8a4 100644
--- a/tests/matrix_test.go
+++ b/tests/matrix_test.go
@@ -22,9 +22,9 @@ func TestMatrixApp(tb *tbase.T) {
 func MxTest(t *testing.T) {
 	ctx := t.Ctx
 	t.AssertEqual(len(ctx.Services()), 3)
-	rcvr := message.SimpleAddress("cell-0")
-	msg := message.SimpleMessage("create")
-	lib.Send(ctx, rcvr, msg)
+	rcvr := ctx.Services()["cell-0"]
+	msg := message.SimpleMessage("create").WithSender(rcvr)
+	rcvr.Send(msg)
 }
 
 // action handlers
diff --git a/tests/scopes_test.go b/tests/scopes_test.go
index 2af5e6a..6a5e281 100644
--- a/tests/scopes_test.go
+++ b/tests/scopes_test.go
@@ -24,7 +24,7 @@ func TestScopesApp(tb *tbase.T) {
 
 func AppTest(t *testing.T) {
 	ctx := t.Ctx
-	t.AssertEqual(len(ctx.Services()), 5)
+	t.AssertEqual(len(ctx.Services()), 4)
 }
 
 func ConfigTest(t *testing.T) {
@@ -32,8 +32,6 @@ func ConfigTest(t *testing.T) {
 	t.AssertEqual(cfg.Name(), "testing")
 	appCfg := cfg.(*app.Cfg)
 	t.AssertEqual(appCfg.Home, ".")
-	confCtx := t.Ctx.Services()["config"]
-	t.AssertEqual(confCtx.Config().Name(), "config")
 }
 
 func SendTest(t *testing.T) {