diff --git a/pkg/args/args.go b/pkg/args/args.go
index a840c6e..305b9af 100644
--- a/pkg/args/args.go
+++ b/pkg/args/args.go
@@ -92,6 +92,11 @@ func (a *Args) Include(other Iterator) {
 	}
 }
 
+// Len return the number of arguments.
+func (a *Args) Len() int {
+	return len(a.Keys)
+}
+
 // Iter iterates over the args key/values
 func (a *Args) Iter() iter.Seq2[string, ipld.Node] {
 	return func(yield func(string, ipld.Node) bool) {
diff --git a/pkg/args/readonly.go b/pkg/args/readonly.go
index 62c6587..0e4e44f 100644
--- a/pkg/args/readonly.go
+++ b/pkg/args/readonly.go
@@ -14,6 +14,10 @@ func (r ReadOnly) GetNode(key string) (ipld.Node, error) {
 	return r.args.GetNode(key)
 }
 
+func (r ReadOnly) Len() int {
+	return r.args.Len()
+}
+
 func (r ReadOnly) Iter() iter.Seq2[string, ipld.Node] {
 	return r.args.Iter()
 }
diff --git a/pkg/meta/meta.go b/pkg/meta/meta.go
index bf12815..9273bbc 100644
--- a/pkg/meta/meta.go
+++ b/pkg/meta/meta.go
@@ -192,6 +192,11 @@ func (m *Meta) Include(other Iterator) {
 	}
 }
 
+// Len returns the number of key/values.
+func (m *Meta) Len() int {
+	return len(m.Values)
+}
+
 // Iter iterates over the meta key/values
 func (m *Meta) Iter() iter.Seq2[string, ipld.Node] {
 	return func(yield func(string, ipld.Node) bool) {
diff --git a/pkg/meta/readonly.go b/pkg/meta/readonly.go
index 26d667d..4e6ddfb 100644
--- a/pkg/meta/readonly.go
+++ b/pkg/meta/readonly.go
@@ -43,6 +43,10 @@ func (r ReadOnly) GetNode(key string) (ipld.Node, error) {
 	return r.meta.GetNode(key)
 }
 
+func (r ReadOnly) Len() int {
+	return r.meta.Len()
+}
+
 func (r ReadOnly) Iter() iter.Seq2[string, ipld.Node] {
 	return r.meta.Iter()
 }