diff --git a/README.md b/README.md
index ed8a581663..833813f860 100644
--- a/README.md
+++ b/README.md
@@ -186,6 +186,12 @@ $ nix run .#t1.<config-name>.ip.emu-omreader -- run --dump-methods
 
   ##### `dlen` : Integer
 
+  ##### `extensionsJson` : Json
+
+  | Field                           | Type   |
+  |---------------------------------|--------|
+  | `[*]`                           | string |
+
   ##### `decoderInstructionsJson` | `decoderInstructionsJsonPretty` : Json
 
   | Field                           | Type   |
diff --git a/omreader/src/Main.scala b/omreader/src/Main.scala
index 78a3773493..dc783cd36f 100644
--- a/omreader/src/Main.scala
+++ b/omreader/src/Main.scala
@@ -47,6 +47,11 @@ object Main {
     println(simplyGetT1Reader(mlirbcFile).dlen)
   }
 
+  @main
+  def extensionsJson(@arg(name = "mlirbc-file") mlirbcFile: os.Path) = {
+    println(simplyGetT1Reader(mlirbcFile).extensionsJson)
+  }
+
   @main
   def decoderInstructionsJson(@arg(name = "mlirbc-file") mlirbcFile: os.Path) = {
     println(simplyGetT1Reader(mlirbcFile).decoderInstructionsJson)
diff --git a/omreaderlib/src/Interface.scala b/omreaderlib/src/Interface.scala
index 56e5293f12..503a276fa4 100644
--- a/omreaderlib/src/Interface.scala
+++ b/omreaderlib/src/Interface.scala
@@ -69,6 +69,11 @@ class T1Reader private[omreaderlib](evaluator: PanamaCIRCTOMEvaluator, basePath:
   }
   def decoderInstructionsJson: String = ujson.write(decoderInstructionsJsonImpl)
   def decoderInstructionsJsonPretty: String = ujson.write(decoderInstructionsJsonImpl, 2)
+  def extensionsJson: String = {
+    val extensions = t1.field("extensions").asInstanceOf[PanamaCIRCTOMEvaluatorValueList]
+    val j = extensions.elements.map(_.asInstanceOf[PanamaCIRCTOMEvaluatorValuePrimitiveString].toString)
+    ujson.write(j)
+  }
 
   def dumpMethods(): Unit = {
     val mirror = runtimeMirror(getClass.getClassLoader).reflect(this)
diff --git a/t1/src/T1.scala b/t1/src/T1.scala
index 64daf2ddc4..3efd4ba48f 100644
--- a/t1/src/T1.scala
+++ b/t1/src/T1.scala
@@ -37,6 +37,12 @@ class T1OM extends Class {
   val dlenIn = IO(Input(Property[Int]()))
   dlen := dlenIn
 
+  @public
+  val extensions = IO(Output(Property[Seq[String]]()))
+  @public
+  val extensionsIn = IO(Input(Property[Seq[String]]()))
+  extensions := extensionsIn
+
   @public
   val lanes = IO(Output(Property[Seq[AnyClassType]]()))
   @public
@@ -340,6 +346,7 @@ class T1(val parameter: T1Parameter)
 
   omInstance.vlenIn := Property(parameter.vLen)
   omInstance.dlenIn := Property(parameter.dLen)
+  omInstance.extensionsIn := Property(parameter.extensions)
 
   /** the LSU Module */