diff --git a/go.mod b/go.mod
index bfa2981..fb58021 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module code.osinet.fr/fgm/izidic
 
 go 1.19
+
+require github.com/google/go-cmp v0.5.9
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..62841cd
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
diff --git a/izidic.go b/izidic.go
index 16a657f..7e17b1a 100644
--- a/izidic.go
+++ b/izidic.go
@@ -11,6 +11,7 @@ package izidic
 import (
 	"errors"
 	"fmt"
+	"sort"
 	"sync"
 )
 
@@ -37,6 +38,25 @@ func (dic *Container) Freeze() {
 	dic.frozen = true
 }
 
+// Names returns the names of all the parameters and instances defined on the container.
+func (dic *Container) Names() map[string][]string {
+	dump := map[string][]string{
+		"params":   make([]string, 0, len(dic.parameters)),
+		"services": make([]string, 0, len(dic.serviceDefs)),
+	}
+	dic.RLock()
+	defer dic.RUnlock()
+	for k := range dic.parameters {
+		dump["params"] = append(dump["params"], k)
+	}
+	sort.Strings(dump["params"])
+	for k := range dic.serviceDefs {
+		dump["services"] = append(dump["services"], k)
+	}
+	sort.Strings(dump["services"])
+	return dump
+}
+
 // Register registers a service with the container.
 func (dic *Container) Register(name string, fn Service) {
 	if dic.frozen {
diff --git a/izidic_test.go b/izidic_test.go
index fc34644..d2b7c5f 100644
--- a/izidic_test.go
+++ b/izidic_test.go
@@ -3,21 +3,25 @@ package izidic
 import (
 	"fmt"
 	"testing"
+
+	"github.com/google/go-cmp/cmp"
 )
 
-func TestContainer_Service(t *testing.T) {
-	const expected = "s1s2"
-	s1 := func(c *Container) (any, error) {
+var (
+	s1 = func(c *Container) (any, error) {
 		return "s1", nil
 	}
-	s2 := func(c *Container) (any, error) {
+	s2 = func(c *Container) (any, error) {
 		s1, err := c.Service("s1")
 		if err != nil {
 			return nil, fmt.Errorf("could not get service s1: %w", err)
 		}
 		return s1.(string) + "s2", nil
 	}
+)
 
+func TestContainer_Service(t *testing.T) {
+	const expected = "s1s2"
 	dic := New()
 	dic.Register("s1", s1)
 	dic.Register("s2", s2)
@@ -33,3 +37,24 @@ func TestContainer_Service(t *testing.T) {
 		t.Fatalf("got %q but expected %q", actual, expected)
 	}
 }
+
+func TestContainer_All(t *testing.T) {
+	var (
+		vpt *string
+		vt  string
+	)
+	dic := New()
+	dic.Store("p1", vt)
+	dic.Store("p2", vpt)
+	dic.Register("s1", s1)
+	dic.Register("s2", s2)
+
+	actual := dic.Names()
+	expected := map[string][]string{
+		"params":   {"p1", "p2"},
+		"services": {"s1", "s2"},
+	}
+	if !cmp.Equal(actual, expected) {
+		t.Logf("unequal results: %v", cmp.Diff(actual, expected))
+	}
+}