diff --git a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/Binary.kt b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/Binary.kt
deleted file mode 100644
index 2b502f12..00000000
--- a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/Binary.kt
+++ /dev/null
@@ -1,6 +0,0 @@
-package hep.dataforge.io
-
-import kotlinx.io.core.Input
-
-//TODO replace by abstraction
-typealias Binary = Input
\ No newline at end of file
diff --git a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/BinaryMetaFormat.kt b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/BinaryMetaFormat.kt
index fc983072..0e73934a 100644
--- a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/BinaryMetaFormat.kt
+++ b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/BinaryMetaFormat.kt
@@ -8,8 +8,8 @@ import kotlinx.io.core.readText
 import kotlinx.io.core.writeText
 
 object BinaryMetaFormat : MetaFormat {
-    override fun write(meta: Meta, out: Output) {
-        out.writeMeta(meta)
+    override fun write(obj: Meta, out: Output) {
+        out.writeMeta(obj)
     }
 
     override fun read(input: Input): Meta {
diff --git a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/Envelope.kt b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/Envelope.kt
index 56a7e9be..1a9e58d7 100644
--- a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/Envelope.kt
+++ b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/Envelope.kt
@@ -3,10 +3,11 @@ package hep.dataforge.io
 import hep.dataforge.meta.Meta
 import hep.dataforge.meta.get
 import hep.dataforge.meta.string
+import kotlinx.io.core.Input
 
 interface Envelope {
     val meta: Meta
-    val data: Binary?
+    val data: Input?
 
     companion object {
 
@@ -18,9 +19,16 @@ interface Envelope {
         const val ENVELOPE_DATA_TYPE_KEY = "$ENVELOPE_NODE.dataType"
         const val ENVELOPE_DESCRIPTION_KEY = "$ENVELOPE_NODE.description"
         //const val ENVELOPE_TIME_KEY = "@envelope.time"
+
     }
 }
 
+class SimpleEnvelope(override val meta: Meta, val dataProvider: () -> Input?) : Envelope{
+    override val data: Input?
+        get() = dataProvider()
+
+}
+
 /**
  * The purpose of the envelope
  *
@@ -40,4 +48,5 @@ val Envelope.dataType: String? get() = meta[Envelope.ENVELOPE_DATA_TYPE_KEY].str
  *
  * @return
  */
-val Envelope.description: String? get() = meta[Envelope.ENVELOPE_DESCRIPTION_KEY].string
\ No newline at end of file
+val Envelope.description: String? get() = meta[Envelope.ENVELOPE_DESCRIPTION_KEY].string
+
diff --git a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/IOFormat.kt b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/IOFormat.kt
new file mode 100644
index 00000000..ce58c05d
--- /dev/null
+++ b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/IOFormat.kt
@@ -0,0 +1,10 @@
+package hep.dataforge.io
+
+import kotlinx.io.core.Input
+import kotlinx.io.core.Output
+
+
+interface IOFormat<T : Any> {
+    fun write(obj: T, out: Output)
+    fun read(input: Input): T
+}
\ No newline at end of file
diff --git a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/JsonMetaFormat.kt b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/JsonMetaFormat.kt
index 6b53a2fa..bd6fa81a 100644
--- a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/JsonMetaFormat.kt
+++ b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/JsonMetaFormat.kt
@@ -14,8 +14,8 @@ import kotlinx.serialization.json.*
 
 object JsonMetaFormat : MetaFormat {
 
-    override fun write(meta: Meta, out: Output) {
-        val str = meta.toJson().toString()
+    override fun write(obj: Meta, out: Output) {
+        val str = obj.toJson().toString()
         out.writeText(str)
     }
 
diff --git a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/MetaFormat.kt b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/MetaFormat.kt
index 50e91248..61969536 100644
--- a/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/MetaFormat.kt
+++ b/dataforge-io/src/commonMain/kotlin/hep/dataforge/io/MetaFormat.kt
@@ -1,15 +1,14 @@
 package hep.dataforge.io
 
 import hep.dataforge.meta.Meta
-import kotlinx.io.core.*
+import kotlinx.io.core.BytePacketBuilder
+import kotlinx.io.core.ByteReadPacket
+import kotlinx.io.core.toByteArray
 
 /**
  * A format for meta serialization
  */
-interface MetaFormat {
-    fun write(meta: Meta, out: Output)
-    fun read(input: Input): Meta
-}
+interface MetaFormat: IOFormat<Meta>
 
 /**
  * ServiceLoader compatible factory